Foundations of Essential Oil Therapy

Watch About the Aromatherapy Consultation with Jade

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Introduction

The art and science of blending is one of the most fascinating, dynamic, and creative aspects of aromatherapy. Considered a mystery to some and a science to others, this chapter has been designed to support and enhance skills for effective yet creative and unique blending. Designing a unique blend for each client is the very heart of holistic aromatherapy.

In the words of Maury, “To reach the individual we need an individual remedy. Each of us is a unique message. It is only the unique remedy which will suffice. We must, therefore, seek odoriferous substances which present affinities with the human being we intend to treat, those which will compensate for his deficiencies and those which will make his faculties blossom. It was by searching for this remedy that we encountered the individual prescription which on all points represents the identity of the individual.”

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STAGE ONE: THE CONSULTATION (ASSESSMENT)

A consultation is designed to collect information or data regarding the client’s current state of health; general lifestyle, including diet and exercise; emotional well-being; and current/past medical history.

A consultation supports the therapist’s understanding of the nature of the condition, how it is affecting the individual client, and what intervention would be most beneficial.

A consultation is not designed to diagnose an illness or disorder as these are beyond the scope of practice for aromatherapists and other complementary healthcare practitioners. Only physicians are able to diagnose.

Within a holistic framework, the consultation is designed to:

• Gather information from the client including the client’s current state of health, general lifestyle (including diet and exercise), emotional well-being, and current/past medical history
• Evaluate the nature of the condition to be addressed, whether it be physical, emotional/mental, spiritual/energetic, or a combination of all three
• Provide the foundation for designing and performing a safe, knowledgeable, and effective treatment based upon the individual’s needs
• Build a professional relationship between client and practitioner

A sample consultation form is provided on the next page. This form should be used for your case studies. Feel free to make changes or adjustments to the questions as desired. You may also use your own intake form, if you have one. Just remember to ask a balance of questions for emotional and physical health/well-being.

Blank Consultation form. or Blank consultation (word doc)

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Aromatherapy and Stress

Having covered some of the basic anatomy and physiology of olfaction, it should come as no surprise that essential oils and their aromas can play a role in reducing not only stress but stress-related disorders. According to Sapolsky (2004), “the diseases of modern times are ones of slow accumulation of damage, such as heart disease, cancer, cerebrovascular disorders. We have also come to recognize the vastly complex intertwining of our biology and our emotions, the endless ways in which our personality, feelings, and thoughts both reflect and influence the events in our bodies. We have come to appreciate that stress can make us sick, and a critical shift in medicine has been the recognition that many of the damaging diseases of slow accumulation can be either caused or made far worse by stress”.

So, what is stress? Stress, or the stress response, can be defined as the body’s response to any demand made upon it. A stressor is anything that can trigger a stress response. Each stressor may initiate a different reaction depending on the type of stressor, the duration it persists, the individual’s abilities to cope, and the amount of social support the individual has in his/her life.

The two types of stressors include external stressors and internal stressors. According to the University of Maryland Medical Center (2004), external stressors include adverse physical conditions (such as pain or hot or cold temperatures) or stressful psychological environments (such as poor working conditions or abusive relationships). Internal stressors can be physical (infections, inflammation) or psychological. An example of an internal psychological stressor is intense worry about a harmful event that may or may not occur. Sapolksy, in his book “Why Zebras Don’t Get Ulcers,” elucidates on this further by saying, “Sustained psychological stress is a recent invention, mostly limited to humans and other social primates. We can experience wildly strong emotions (provoking our bodies into a stress response) linked to mere thoughts”.

Duration of Stressors

Not all stress is bad stress. Stress is to the human condition what tension is to the violin string—too little and the music is dull and raspy; too much and the music is shrill or the string snaps. Understanding the types of stressors, as well as their possible duration, can be beneficial in creating techniques that can support one’s ability to cope with stress. Stress can be acute (short-lived), episodic, or chronic (longer time frame).

Acute vs. Chronic Stress: What’s the Difference?

Acute stress is the most common form of stress we all experience on a day-to-day basis. Acute stress is the body’s immediate response to a perceived threat or challenge. It’s characterized by a rapid onset and short duration, typically lasting from a few minutes to a few hours. The acute stress response, also known as the “fight-or-flight” response, is a survival mechanism that prepares us to confront or escape danger.

Acute stress is short-term and can be thrilling and exciting in small doses, but too much can be exhausting and overwhelming. An example of acute stress is when you are on a time schedule, and you’re running late. Acute stress doesn’t have time to do extensive damage to your health because it is short-term stress.

The most common symptoms of acute stress include emotional distress, a combination of anger, irritability, or anxiety and depression; tension headaches; muscular aches and pains; upset digestive system, including heartburn, flatulence, diarrhea, constipation, or irritable bowel syndrome; rapid heartbeat; sweaty palms; migraines; shortness of breath; or chest pain. All forms of acute stress tend to be manageable.

Episodic acute stress is similar to what has been commonly called type A personality. It occurs when an individual is always in a rush; they take on too much, have too many irons in the fire, and seem always to be doing something or going somewhere. If something can go wrong, it often does. Episodic acute stress is similar to acute stress. However, episodic stress has acute stressors daily or even hourly.

In some instances, the individual has made it a way of life. Individuals who live with acute episodic stress are often over-aroused, short-tempered, irritable, anxious, and tense. They seem to live off their own nervous energy. Symptoms of episodic stress include persistent tension headaches, migraines, hypertension, chest pain, and heart disease.

In contrast, chronic stress is the persistent activation of the stress response over weeks, months, or even years. Chronic stressors are often psychological in nature, such as job strain, financial hardship, or relationship conflicts. Unlike acute stressors, which the body is well-equipped to handle, chronic stress can take a heavy toll on our physical and mental health.

Chronic stress can be caused by many different life events, including poverty, dysfunctional families, long-term relationship problems, persistent financial worries, loneliness, challenging marriages, or a despised job or career.

The Stress Paradox

Stress is an inevitable part of life, and we all experience it to varying degrees. Like the tension on a violin string, stress can either create beautiful music or cause the string to snap. We need a certain amount of stress to keep us motivated and engaged, but too much stress can lead to a host of physical and mental health problems. In this lesson, we’ll explore the nature of stress, its impact on our bodies and minds, and strategies for managing it effectively.

The Many Faces of Stress

As you have learned in the first section of this lesson, stress comes in many forms, from the acute stress of a job interview to the chronic stress of financial hardship or a difficult relationship. Stressors can be physical, like an injury or illness, or psychological, like worry or anxiety. They can be major life events, like moving to a new city, or daily hassles, like traffic jams or long lines at the grocery store. What’s important to recognize is that our individual perceptions and responses to stress are shaped by a complex interplay of factors, including our genes, personality, life experiences, and social and cultural context.

The Body’s Balancing Act: Homeostasis and Allostasis

To understand the impact of stress on health, it’s important to grasp two key concepts: homeostasis and allostasis. Homeostasis refers to the body’s ability to maintain a stable internal environment despite changes in the external environment. It involves regulating various physiological parameters, such as body temperature and blood sugar levels, within a narrow range of values.

Allostasis, on the other hand, is the process of achieving stability through change. It involves the active adjustment of physiological systems in response to challenges or demands, allowing the body to adapt to changing circumstances. While homeostasis is essential for maintaining vital functions, allostasis enables us to cope with stressors and promote survival.

The Price of Adaptation: Allostatic Load

When the stress response is activated repeatedly or for prolonged periods, as in the case of chronic stress, it can lead to wear and tear on the body known as allostatic load. Allostatic load represents the cumulative burden of chronic stress and the cost of constantly adapting to life’s challenges.

Over time, allostatic load can contribute to the development of various health problems, including cardiovascular disease, metabolic disorders, immune dysfunction, and mental health issues. It can also accelerate the aging process and increase the risk of cognitive decline and neurodegenerative disorders.

Understanding the Balancing Act:
The Sympathetic and Parasympathetic Nervous Systems

The autonomic nervous system is a complex network of nerves that works tirelessly to keep our bodies functioning properly, even when we’re not consciously thinking about it. This system is divided into two main branches: the sympathetic nervous system and the parasympathetic nervous system. These two branches work together to maintain a delicate balance in our bodies, helping us respond to both external and internal changes.

The sympathetic nervous system is often referred to as the “fight or flight” response. When we encounter a stressful situation, this system kicks into gear, preparing our bodies to either confront the challenge or run away from it. It does this by increasing our heart rate, raising our blood pressure, and sending extra blood to our muscles. This can be very helpful in emergency situations, but if we’re constantly stressed, our sympathetic nervous system can become overactive, leading to health problems.

On the other hand, the parasympathetic nervous system is responsible for helping us relax and rest. It’s sometimes called the “rest and digest” system because it helps our bodies recover from stress and promotes activities like digestion and sleep. When the parasympathetic system is activated, our heart rate slows down, our blood pressure drops, and our muscles relax.

Ideally, these two systems should work together in harmony, allowing us to respond to stress when necessary and then return to a state of relaxation. However, in our modern world, many people find themselves in a constant state of stress, which means their sympathetic nervous system is working overtime. This can lead to an imbalance between the two branches of the autonomic nervous system, which can contribute to a wide range of health issues, from high blood pressure and heart disease to digestive problems and chronic pain.

To maintain good health, it’s important to find ways to balance the activity of the sympathetic and parasympathetic nervous systems. This can include practicing relaxation techniques like deep breathing or meditation, getting regular exercise, and making time for activities that bring us joy and help us unwind. By taking steps to manage stress and promote relaxation, we can help keep our autonomic nervous system in balance and support our overall health and well-being.

The Stress Response: A Symphony of Hormones

The body’s response to stress is orchestrated by two main systems: the sympathetic-adrenal-medullary (SAM) axis and the hypothalamic-pituitary-adrenal (HPA) axis. When we perceive a stressor, the SAM axis is activated first, triggering the release of epinephrine (adrenaline) and norepinephrine from the adrenal glands. These hormones rapidly prepare the body for action by increasing heart rate, blood pressure, and blood sugar levels, among other effects.

If the stressor persists, the HPA axis kicks in, leading to the release of cortisol from the adrenal cortex. Cortisol is a powerful stress hormone that helps to sustain the stress response by mobilizing stored energy, suppressing immune function, and modulating brain areas involved in learning, memory, and emotion. While cortisol is essential for coping with stress in the short term, chronic elevation of cortisol levels can have detrimental effects on health.

Conditions Commonly Caused By or Made Worse By Stress
Angina	Hypertension	Premenstrual syndrome
Anxiety	Diabetes – Type II Adult Onset	Reduced feelings of pleasure
Asthma	Headaches/Migraines	Rheumatoid arthritis
Autoimmune disorders	Immune suppression	Skin disorders: hives, psoriasis, rosacea, eczema
Cancer	Irritable bowel syndrome	Sleep disturbances: insomnia
Cardiovascular disease	Lack of sexual drive	Slow wound healing
Common cold	Menstrual irregularities	Substance abuse
Constipation	Muscle tension	Susceptibility to infections
Depression	Muscular and joint pain	Ulcers
Eating disorders	Periodontal disease	Ulcerative colitis

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Stress and the Brain: A Delicate Balance

The brain is both the target and the maestro of the stress response. Chronic stress can alter the structure and function of key brain regions involved in memory, emotion regulation, and decision-making. The hippocampus, which is crucial for learning and memory, is particularly vulnerable to the effects of chronic stress. Prolonged exposure to high levels of cortisol can actually shrink the hippocampus, impairing its ability to form new memories.

The amygdala, a brain region involved in processing emotions like fear and anxiety, can become hyperactive in response to chronic stress, leading to increased feelings of anxiety and irritability. The prefrontal cortex, responsible for attention, planning, and impulse control, can also be impaired by chronic stress, leading to difficulties with focus and decision-making.

The Mind-Body Connection: Stress and Mental Health

Stress and mental health are intimately connected. Chronic stress is a significant risk factor for the development of mental health problems, such as depression, anxiety disorders, and post-traumatic stress disorder (PTSD). Dysregulation of the HPA axis, characterized by either elevated or blunted cortisol levels, has been linked to a variety of mental health conditions.

Depression, in particular, is often associated with HPA axis overactivity and elevated cortisol levels. High cortisol can disrupt normal circadian rhythms and sleep patterns, impair brain structure and function, increase inflammation, and interfere with neurotransmitter systems involved in mood regulation. Anxiety disorders and PTSD have also been linked to HPA axis dysfunction, though the patterns are more variable than in depression.

Building Resilience: Strategies for Managing Stress

While we can’t eliminate stress from our lives entirely, we can learn to manage it more effectively. Building resilience, or the ability to bounce back from adversity, is key to mitigating the negative effects of stress on our health and well-being. Here are some evidence-based strategies for managing stress and promoting resilience:

1. Practice relaxation techniques: Deep breathing, progressive muscle relaxation, and mindfulness meditation can help to calm the nervous system and reduce stress.
2. Engage in regular physical activity: Exercise is a potent stress-buster that can help to improve mood, reduce anxiety, and promote overall health.
3. Maintain a healthy diet: Eating a balanced diet rich in whole foods, fruits, and vegetables can help to support brain health and reduce inflammation.
4. Get enough sleep: Adequate sleep is essential for managing stress and promoting resilience. Aim for 7-9 hours of sleep per night.
5. Connect with others: Social support is a powerful buffer against stress. Cultivate meaningful relationships with friends, family, and community members.
6. Find purpose and meaning: Engaging in activities that align with your values and give your life a sense of purpose can help to reduce stress and promote well-being.
7. Incorporate aromatherapy: Essential oils used in inhalation, topical application, or diffusion can have calming and soothing effects, helping to reduce stress and promote relaxation.

Befriending Stress, Cultivating Resilience

Stress is an integral part of the human experience, and while we may not be able to eliminate it entirely, we can learn to manage it more effectively. By understanding the complex nature of stress, its impact on our bodies and minds, and the strategies for building resilience, we can cultivate a greater sense of well-being and thrive in the face of life’s challenges.

Aromatherapy, in particular, offers a powerful tool for managing stress and promoting relaxation. By incorporating essential oils into our daily routines and self-care practices, we can harness the therapeutic benefits of these natural remedies and support our overall health and well-being.

Ultimately, the key to managing stress lies in finding a balance – in recognizing that stress is not inherently bad but rather a natural response to the demands of life. By befriending our stress response and cultivating resilience, we can navigate the ups and downs of life with greater ease and grace and unlock our full potential for growth and transformation.

The Far-Reaching Impact of Stress: A Call to Action

Chronic stress and its impact on the HPA axis have far-reaching consequences for both individual and public health. Despite the numerous and serious stress-related diseases mentioned throughout this lesson, the medical profession has yet to define a specific category of illnesses that encompasses the effects of allostatic load. As a result, prevention and treatment of stress and its impact on the HPA axis are often overlooked in preventative care and treatment plans.

The consequences of this oversight are evident in the widespread symptoms of HPA axis dysregulation in modern society. Beyond overt dysfunction and disease, such as reproductive disorders, insulin resistance, chronic fatigue syndrome, and autoimmune disorders, many people struggle with a host of stress-related problems. Fatigue, insomnia, emotional frustration, digestive issues, weight problems, menstrual irregularities, infertility, headaches, and increased susceptibility to infections are just a few examples of the ways in which chronic stress can manifest in our daily lives.

Addressing chronic stress as part of the prevention and treatment of chronic illness is not merely a nod to a holistic approach – it is a crucial component of a comprehensive medical and public health strategy to reduce the burden of chronic health problems. By recognizing the significant impact of stress on health and well-being, we can take proactive steps to mitigate its effects and promote resilience at both the individual and societal levels.

As aromatherapy practitioners, we have a unique opportunity to address the impact of stress and provide stress-reducing tools as an integral part of our care. By understanding the complex interplay between stress and disease, we can tailor our therapeutic approaches to the specific needs of each client. This pragmatic approach to the psychobiology of stress and human disease allows us to create effective, personalized interventions that support both physical and emotional well-being.

In a world where chronic stress has become a pervasive challenge, the role of aromatherapy in promoting relaxation, reducing stress, and building resilience cannot be overstated. By incorporating essential oils and other stress-management techniques into our practice, we can empower our clients to navigate life’s challenges with greater ease and grace, and ultimately, to achieve optimal health and well-being.

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The Relaxation Response

Marguerite Maury observed that the power of aromatherapy in counteracting stress lies in the combination of essential oils and massage, both of which are capable of relaxing and reducing stress, reducing pain, lowering blood pressure, stimulating/enhancing the immune system, and relieving muscular tension.

The Relaxation Response is a natural state of deep rest that can be entered into by using specific relaxation techniques. It was first identified and coined by Dr. Herbert Benson, a professor, cardiologist, and founder of Harvard’s Mind/Body Medical Institute. Through his research, Dr. Benson found that by using simple relaxation methods, people could lower their stress levels, reduce their blood pressure and resting heart rate, and promote an overall sense of well-being.

The Relaxation Response works by engaging the parasympathetic nervous system, which is responsible for rest and repair in the body. It’s essentially the opposite of the “fight-or-flight” stress response, which revs up the sympathetic nervous system and prepares the body to face perceived threats or dangers.

When you elicit the Relaxation Response, a number of positive physiological changes occur:

• Muscle tension decreases
• Breathing slows and deepens
• Heart rate slows down
• Blood pressure decreases
• Stress hormone levels drop
• Blood flow to the brain and vital organs increases

Some of the key benefits of eliciting the Relaxation Response include:

• Lowered stress and anxiety levels
• Decreased muscle tension and pain
• Improved mood and emotional wellbeing
• Better sleep
• Increased mental clarity and focus
• Enhanced immune function
• Greater resiliency to life’s challenges

With regular practice, the Relaxation Response should come more easily and require less effort to achieve. Most experts recommend aiming for 1-2 practice sessions per day, for about 10-20 minutes each time. Over time, regularly entering into a state of deep relaxation can help reverse the physical toll of chronic stress and promote greater health and resiliency. It’s a simple but powerful way to restore balance to the mind and body.

Here is one simple technique taught by Dr. Benson:

1. Sit quietly in a comfortable position.
2. Close your eyes.
3. Deeply relax all your muscles.
4. Breathe through your nose, paying attention to your breath.
5. As you breathe out, silently say the word “one” to yourself. Breathe easily and naturally.
6. Continue steps 4 and 5 for 10 to 20 minutes.
7. Open your eyes and sit quietly for a moment before standing up.

Tips:

• Add Aromatherapy by diffusing essential oils into the room you are in.
• When you ‘breathe in through your nose,’ have an essential oil or blend you can smell.
• Add aromatherapy at the end by having a personal inhaler to anchor the relaxation response.
• Pick a quiet place and time of day when you won’t be disturbed.
• Let go of expectations. Maintain a passive attitude and let relaxation happen at its own pace.
• When distracting thoughts occur, don’t dwell on them. Simply return your focus to your breath.
• Choose a soothing, meaningless word to repeat to avoid stimulating unnecessary thoughts.
• Don’t practice within 2 hours of a meal, as digestion can interfere with relaxation.

Enhancing the Relaxation Response with Olfactory Aromatherapy

Integrating aromatherapy into the practice of eliciting the Relaxation Response can enhance the calming effects and make it easier for individuals to achieve a state of deep rest. As previously discussed, the sense of smell has a powerful influence on emotions and physiology due to the direct connection between the olfactory system and the limbic system in the brain.

When individuals inhale essential oils known for their relaxing properties, such as lavender, chamomile, or bergamot, the aromatic compounds send signals to the limbic system, triggering a cascade of beneficial physiological changes. These oils can help slow down breathing, reduce heart rate and blood pressure, and lower stress hormone levels, all of which are key elements of the Relaxation Response.

Ways to Use Aromatherapy for Stress Reduction and Relaxation

There are a number of different ways to use essential oils to promote relaxation, reduce stress, and elicit the Relaxation Response. As individuals breathe in the soothing scent, they should focus on taking slow, deep breaths and allow themselves to fully relax and release any tension or stress. Here are some effective methods:

1. Aromatherapy Inhaler: This is a convenient and portable option that can be made for clients or customers. They can easily use the inhaler throughout the day as needed to manage stress and promote relaxation.
2. Aromatic Baths: Creating a relaxing bath experience with sea salts, milk powder, or honey infused with essential oils can provide a luxurious and stress-relieving experience.
3. Diffusers: Using an essential oil diffuser in a room or workspace can help create a calming atmosphere and promote relaxation throughout the day.
4. Direct Palm Inhalation: For a quick and easy stress-relief technique, individuals can place a drop of essential oil in the palm of their hand, rub their hands together, cup them over the nose, and take a few deep breaths.
5. Roll-on: A pre-diluted essential oil blend in a roll-on bottle can be applied to pulse points, such as the wrists, temples, or behind the ears, for a convenient and targeted stress-relief solution.
6. Self-massage oil: Massaging a body oil with essential oils into the skin can help relax tense muscles, promote circulation, and provide a calming aromatherapy experience.
7. Massage Therapy Session with Customized Essential Oil Blend: Receiving a professional massage with a personalized essential oil blend can offer a deeply relaxing and stress-relieving experience, addressing both physical and emotional tension.

By combining the power of aromatherapy with the techniques for eliciting the Relaxation Response, individuals can create a multi-sensory experience that deepens their state of relaxation and enhances the overall benefits for the mind and body. Regular practice of this integrated approach can help build greater resilience to stress and promote a sense of balance and well-being in daily life for oneself, family members, or clients.

Aromatherapy for Stress Relief and Relaxation

In this module, the concept of stress and its potential impact on health have been explored. As aromatherapists, we are uniquely positioned to create therapeutic blends that can help individuals reduce the effects of stress on their physical and emotional well-being.

When selecting essential oils for stress relief, it is important to consider both the physical and emotional manifestations of stress. For instance, if a client is experiencing physical symptoms such as tight neck and shoulders or constipation, certain essential oils can be chosen to target those specific concerns. On the other hand, if a client is struggling with emotional symptoms like anxiety, worry, or depression, a different set of essential oils may be more appropriate.

Ideally, a well-crafted aromatherapy blend should address both the physical and emotional aspects of stress for a more comprehensive and holistic approach. However, when creating blends for relaxation and emotional well-being, it is crucial to ensure that the client finds the aroma pleasant and appealing. A pleasing scent can greatly enhance the overall experience and effectiveness of the aromatherapy treatment, as it promotes a positive emotional response and encourages consistent use.

By carefully considering the specific needs and preferences of each individual, aromatherapists can develop personalized essential oil blends that effectively target stress, promote relaxation, and support overall well-being. Through the skillful use of aromatherapy, we can empower our clients to manage stress and cultivate a greater sense of balance and resilience in their daily lives.

Here are some general therapeutic goals when blending for stress include:

• Reduce pain and muscular tension
• Facilitate immune system function
• Enhance a healing and calm emotional state
• Decrease sympathetic nervous system activity
• Encourage stress-reducing activities and coping skills
• Relieve/reduce stress
• Support memory
• Enhance energy levels

Which Essential Oils?

The chart below has been designed to support the application of essential oils for a variety of emotional states. The essential oils provided under each emotional state are given based on their general physiological action, nature, and potential inherent messages (e.g., relax, sedate, ground). This chart includes the essential oils covered in this course. Please feel free to add to the chart as you learn about other essential oils.

 

Essential Oils for Emotional Support and Healing

Emotional State	Essential Oils
Anger, Irritability	Roman chamomile, Clary sage, Frankincense, Helichrysum, Lavender, Tangerine, Ylang ylang
Anxiety	Roman chamomile, Clary sage, Geranium, Helichrysum, Lavender, Patchouli, Pine, Tangerine, Vetiver, Ylang ylang
Aphrodisiac, Frigidity	Clary sage, Fennel, Ginger, Patchouli, Ylang ylang
Burnout, Exhaustion	Roman chamomile, Cypress, Frankincense, Geranium, Helichrysum, Laurel, Lavender, Lemon, Sweet Orange, Peppermint, Rosemary, Tangerine
Calming/Soothing	Roman chamomile, Clary sage, Lavender, Patchouli, Vetiver
Clarity	Eucalyptus, Grapefruit, Juniper berry, Laurel, Lemon, Lemongrass, Sweet Orange, Peppermint, Pine, Rosemary
Cleansing	Eucalyptus, Grapefruit, Juniper berry, Laurel, Lemon, Lemongrass, Sweet Orange, Peppermint, Rosemary
Confusion, Indecision	Cypress, Ginger, Laurel, Lemongrass, Peppermint, Rosemary, Vetiver
Confidence (lack of), Insecurity	Cedarwood, Eucalyptus, Lavender, Tangerine, Vetiver, Ylang ylang
Courage	Cedarwood, Peppermint, Pine, Rosemary, Vetiver
Depression	Clary sage, Frankincense, Geranium, Ginger, Grapefruit, Sweet Orange, Tangerine, Patchouli
Emotional Turmoil	Roman chamomile, Clary sage, Cypress, Frankincense, Helichrysum, Lavender, Patchouli, Tangerine, Vetiver, Ylang ylang
Fears	Cypress, Geranium, Ginger, Lavender, Laurel, Peppermint, Pine, Rosemary, Tangerine
Grounding	Ginger, Vetiver
Grieving, Loss	Helichrysum, Patchouli, Tangerine, Ylang ylang
Heartache	Clary sage, Frankincense, Helichrysum, Lavender, Tangerine
Inspiration, Creativity	Clary sage, Fennel, Grapefruit, Laurel, Lemon, Sweet Orange, Rosemary, Ylang ylang
Letting go	Eucalyptus, Frankincense, Grapefruit, Juniper berry, Laurel, Lemon, Sweet Orange, Pine, Rosemary
Mood Swings	Roman chamomile, Clary sage, Cypress, Fennel, Frankincense, Geranium, Lavender, Patchouli, Tangerine, Vetiver, Ylang ylang
Nervousness	Clary sage, Frankincense, Lavender, Patchouli, Pine, Tangerine, Ylang ylang
Nightmares	Roman chamomile, Lavender, Pine, Tangerine
Panic, Shock	Roman chamomile, Frankincense, Helichrysum, Lavender, Sweet Orange, Tangerine, Vetiver, Ylang ylang

Sample Recipes

Relieve Muscular Tension Massage Oil

• 1 ounce Sesame oil
• 10 drops Lavender (Lavandula angustifolia)
• 6 drops Tangerine (Citrus reticulata)
• 3 drops Clary sage (Salvia sclarea)

Relieve Muscular Pain caused by Tension

• 1/2 ounce (30ml) Jojoba oil
• 1/2 ounce (30ml) Sesame oil
• 7 drops Peppermint (Mentha x piperita)
• 10 drops Rosemary ct cineole (Rosmarinus officinalis)
• 7 drops Lavender (Lavandula angustifolia)

Soothing Inhaler

• 6 drops Bergamot (Citrus bergamia)
• 6 drops Lavender (Lavandula angustifolia)
• 3 drops Roman chamomile (Chamaemelum nobile)
• 10 drops Tangerine (Citrus reticulata)

Clear the Mind Inhaler

• 10 drops Peppermint (Mentha x piperita)
• 15 drops Rosemary (Rosmarinus officinalis)

Serious Calm Inhaler

• 5 drops Roman chamomile (Chamaemelum nobile)
• 5 drops Bergamot (Citrus bergamia)
• 10 drops Lavender (Lavandula angustifolia)
• 3 drops Clary sage (Salvia sclarea)

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The Limbic System: Where Smell Meets Emotion

Despite our modern world often overlooking the power of smell, our brains are still hardwired to pay close attention to scents. Dr. Michael Shipley, a neurobiologist, points out that a significant portion of our brain is dedicated to processing odors. Even if we’re not always consciously aware of smells, they have a direct line to the deepest parts of our brain that influence our behavior and well-being.

This smell-brain connection is thanks to the limbic system, an ancient part of the brain that’s been with us throughout evolution. Brain researcher Paul MacLean explains that the limbic region is closely tied to the hypothalamus, a master control center for hormones and bodily functions. Through this link, the limbic system can profoundly impact our metabolism, stress levels, sexual drive, and more.

But the limbic system isn’t just about physical functions – it’s also the seat of our emotions. From joy to sorrow, anger to affection, this region plays a major role in shaping our feeling states. It’s like an internal sensory system that quickly integrates information and directs our bodies and minds to respond accordingly, whether that’s seeking food, romance, or rest.

And here’s where our sense of smell comes in. The olfactory input has a direct pathway to the limbic system, explaining why aromas can have such a powerful influence on our moods and memories. A single whiff can instantly transport us back to a meaningful moment or evoke a strong emotional response.

Various parts of the limbic system, from the amygdala to the hippocampus to the cingulate gyrus, work together to process olfactory information and tie it to our experiences and feelings. So, while we may not always be conscious of the scents around us, our limbic brain is always paying attention, ready to guide our behaviors and emotions in profound ways.

The Limbic System Structures

The limbic system is centrally located, sitting right under the cerebrum and buried deep beneath the cortex. It includes several key structures:

• Amygdala: Processes emotions, especially fear, anxiety, and aggression. Attaches emotional significance to memories. Also involved in reward and motivation.
• Hippocampus: Responsible for forming new memories about experienced events.
• Anterior Thalamus: Relays sensory information and is involved in sleep, alertness, and awareness.
• Hypothalamus: Regulates autonomic functions like hunger, thirst, and sleep. Responds to emotions.
• Cingulate Gyrus: Plays a crucial role in connecting various brain areas involved in emotion, sensation, and action.

“Limbic system structures are concerned with central (neural) control over the expression of emotions, instinctive behaviors, drives, motivation, and feelings. Both the cerebral cortex and the limbic system have ample access to the brain stem motor areas, permitting them to exercise their respective adaptive and instinctive (stereotyped) controls over behavior.”

A Deeper Dive into Limbic System Structures

 

• The Amygdala

The amygdala is a small almond-shaped region in the forebrain. (amygdala is the Latin word for almond). The amygdala is the integrative center for emotions, emotional behavior, and motivation. It is particularly involved with fear and anxiety, and it plays a central role in aggression. It also plays a role in male sexual motivation. The extraordinary thing is that olfaction is one synapse away from the amygdala! Take a moment to think about the potential implications of this.

The amygdala is a critical center for coordinating behavioral, autonomic, and endocrine responses to environmental stimuli, especially those with emotional content. It is important to the coordinated responses to stress and integrates many behavioral reactions involved in the survival of the individual or of the species, particularly to stress and anxiety. Lesions of the amygdala reduce responses to stress, particularly conditioned emotional responses. Stimulation of the amygdala produces behavioral arousal and can produce directed rage reactions.

The amygdala is the initial part of the brain where a stressor is registered, and it decides whether the stressor is a ‘sign of danger.’ If the ‘image’ is seen as a ‘danger,’ the amygdala sends its alarm – distress signal – to the hypothalamus (stress response).

So here in lies a valuable clue as to the power of aromas. Our sense of smell has direct access to the amygdala and hence can potentially interrupt the stress response at this level, decreasing the magnitude of the sympathetic response to a stressor and supporting the client in taking some ‘breathing space.’

Other important points about the amygdala:
The amygdala is considered the primary pleasure center in the brain, essential to nurturing behavior and fear conditioning. It houses the main circuits that color our experience with emotion and is responsible for assigning emotional significance to sensory information, including intensity (e.g., from mildly interesting to incredibly interesting).

The amygdala, along with the hippocampus, is crucial for the formation of memories. Specifically, the amygdala plays a central role in the types of memories involved in anxiety.

Emotional conditioning is dependent on the amygdala. Once the amygdala attaches emotional significance to sensory information, its emotional evaluation is passed on to the hippocampus, which organizes the information and integrates it with previous memories of similar sensory details. The greater the emotional significance assigned by the amygdala, the more intently the memory is permanently recorded by the hippocampus.

Lesions on the amygdala will affect the emotional coloring and memory of an experience; often, no emotion at all is attached to a remembered experience. Over-sensitivity of the amygdala has been implicated in anxiety, panic disorder, post-traumatic stress disorder (PTSD), and attention deficit hyperactivity disorder (ADHD).

According to Sapolsky, the amygdala actually gets bigger in individuals with post-traumatic stress disorder, and periods of prolonged stress cause an increase in neurons in the amygdala to grow more dendritic processes. It becomes more metabolically reactive than other areas of the brain. Hence, anxiety, fear, and aggression may be more present.

• Hippocampus

The hippocampus is a curved band of gray matter located inside the temporal lobe (humans have two hippocampi, one on each side of the brain). It forms a part of the limbic system and plays a part in learning and memory. The hippocampus is vital for short-term memory as well as for the consolidation of that memory into a long-term form. Factual information appears to be stored in the cerebral cortex. Research shows that the hippocampus is crucial for the development of new memory traces in the brain.

A most recent and amazing corollary discovery is that cells in adult brains are continually dividing and producing new cells. The new growth was discovered in the hippocampus, the center of learning and memory. The hippocampus, like the olfactory epithelium, is capable of neurogenesis, which means the hippocampus is capable of producing new neurons.

According to Sapolsky (2004), the rate of neurogenesis can be regulated. For instance, an enriched learning environment and exercise can increase the rate of neurogenesis, while stress actually inhibits neurogenesis. It has been shown that the hippocampus shrinks in size when an individual is under stress. For example, people who pour out the stress hormones (glucocorticoids) have a diminished hippocampus and, hence, a reduced ability to make new memories or draw on older memories.

• The Anterior Thalamus

For olfaction, the anterior thalamus connects the limbic system with the cerebral cortex. In general, the thalamus acts as a relay station for all sensory stimuli (except olfaction) to the cerebral cortex. The anterior thalamus gets involved once olfactory information has been sent to the septum and amygdala and then on to the hypothalamus, which finally sends the message to the anterior thalamus.

• Hypothalamus

The hypothalamus lies below the thalamus and above the pituitary gland in the heart of the brain. The hypothalamus is a small but crucial region of the brain that acts as a control center for many important functions in the body. Its primary role is to maintain homeostasis, which means keeping the body’s internal environment stable and balanced. The hypothalamus achieves this by receiving information from various sources, processing it, and then sending out signals to regulate different systems in the body.

The three major systems controlled by the hypothalamus for the maintenance of homeostasis (and allostasis) are the autonomic nervous system, the neuroendocrine system, and the limbic system.

Sensory Inputs and Connections
The hypothalamus is uniquely positioned to receive a wide range of sensory information. It receives direct inputs from the smell, taste, visual, and somatosensory systems, as well as internal sensors that monitor blood temperature, blood sugar, mineral levels, and various hormones.

Additionally, the hypothalamus is connected to the limbic system, which includes the hippocampus, amygdala, and cingulate gyrus. These structures provide the hypothalamus with highly processed sensory information and emotional context, allowing it to generate appropriate responses to maintain the body’s well-being.

Image from: Lab Week 9: Hypothalamus, Limbic System, and Thalamus Review (University of Washington)

Endocrine, Autonomic, and Behavioral Regulation

The hypothalamus exerts control over various bodily functions through three main output systems: the endocrine system, the autonomic nervous system, and behavioral regulation. It controls the endocrine system by releasing hormones directly, regulating the release of hormones from the anterior pituitary, and modulating the activity of other endocrine glands through autonomic outputs. The hypothalamus also innervates the preganglionic neurons of the sympathetic and parasympathetic nervous systems, allowing it to regulate autonomic functions and modulate brainstem circuits that control autonomic reflexes.

Hypothalamic control of behavior is mediated by regulating overall arousal and wakefulness, influencing the activation of specific motor patterns, modulating sensory systems, and generating autonomic and endocrine signals that drive conscious awareness of needs and motivate appropriate behaviors. The hypothalamus integrates signals from other brain regions, such as the cerebral cortex and limbic system, to initiate appropriate behavioral responses to maintain homeostasis.

Synopsis of Functions of the Hypothalamus

The hypothalamus is involved in the regulation of several critical physiological processes:

1. Fluid and Electrolyte Balance: Maintains the body’s fluid balance by controlling thirst, drinking behavior, and secretion of hormones that influence kidney function and blood volume.
2. Feeding and Energy Metabolism: Regulates appetite, energy storage, and the conversion of nutrients to fuel, ensuring sufficient energy reserves.
3. Thermoregulation: Maintains body temperature within a narrow range by initiating mechanisms to increase or decrease heat production and dissipation.
4. Reproduction: Regulates reproductive cycles and sexual behavior by controlling the release of reproductive hormones and influencing sexual arousal.
5. Sleep and Wakefulness: Helps regulate the sleep-wake cycle by promoting wakefulness during the day and facilitating sleep at night, working with the body’s circadian rhythm.
6. Stress Responses: Triggers the release of stress hormones and activates the sympathetic nervous system to prepare the body for “fight or flight” responses, helping it cope with and adapt to challenging situations.

Most importantly, the hypothalamus is powerful because it is the meeting place for the body’s two control systems: the autonomic nervous system, which regulates the action of the glands, smooth muscle, and the cardiac (heart) muscle, as well as our response to stress and the endocrine system (via the pituitary) which sends chemical messengers in the form of hormones through the blood to act directly on organs throughout the body.

• Cingulate Gyrus

The cingulate gyrus, a key component of the limbic system, is a curved region of the brain that wraps around the corpus callosum. It plays a crucial role in connecting various brain areas involved in emotion, sensation, and action. You can think of it as a central hub that helps these different regions communicate and work together.

One of the main jobs of the cingulate gyrus is to process emotions. It helps regulate our emotional responses and the bodily changes that come with them, like changes in heart rate or hormone levels. It’s also involved in making decisions based on rewards, so it helps guide our behavior towards things that make us feel good.

Another important function of the cingulate gyrus is in memory. It works with areas like the hippocampus to help form and store long-term memories, especially ones that have an emotional component. It also plays a role in our ability to imagine things and mentally travel through space.

The cingulate gyrus is connected to areas involved in movement and attention, too. It helps translate our emotional states into actions by communicating with motor areas of the brain. It also forms part of a network that directs our attention.

Think of the cingulate gyrus as a busy switchboard operator in the limbic system. It connects areas involved in emotion, memory, attention, and action, helping to integrate our emotional experiences with other brain processes. This allows us to respond to our environment in an adaptive way, with appropriate feelings, memories, and behaviors.

• The Prefrontal cortex

While the prefrontal cortex is not included in this list, it has strong reciprocal connections with many limbic structures, particularly the amygdala, hippocampus, and anterior cingulate cortex. These connections allow the prefrontal cortex to regulate and modulate emotional responses, memory processes, and motivation, which are functions closely associated with the limbic system.

The prefrontal cortex is thought to exert top-down control over limbic regions, allowing for the regulation of emotions, impulse control, and decision-making based on social and emotional cues. Dysfunction in the prefrontal-limbic circuitry has been implicated in various psychiatric disorders, such as depression, anxiety, and post-traumatic stress disorder (PTSD).

Did you know? The prefrontal cortex is involved in emotional items like impulse control, long-term planning, and delayed gratification. It isn’t fully myelinated until the mid-20s, thus accounting for the changes people go through from their teenage years to their early 20s and on to adulthood. I think this helps to know because it makes teenagers and young adults a little bit easier to understand.

All the limbic parts are connected to each other.

Conclusion: These anatomical features of the limbic system and their connections to olfaction provide us with an understanding of how essential oils can influence neuroendocrine, emotional, and physiological functions in humans. It should also now be clear how essential oils may mediate the stress response and thereby reduce, relieve, or prevent stress-related diseases.

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Aromatic Memory-based Response

Aromatherapists, reflexologists, estheticians, and massage therapists are able to utilize the intimate connection of smell with memory to enhance the therapeutic benefit of their treatments. By providing the client with a small bottle of the aromatherapy blend used during the session to take home, one may activate the aromatic memory-based association, thereby allowing the client to feel as if they were back in the massage room, emotionally, physically, and spiritually. How does this work?

According to Kirk-Smith (n/d), a neutral odor can be easily paired with an emotional state in a single session so that it will evoke the same emotional state in another circumstance at a later time. I call this an aromatic memory-based response.

Phase One: Initial Experience

A client arrives for their aromatic massage or bodywork session. The client has specifically requested aromatherapy for their session. The client feels comfortable speaking to the therapist, and the therapist learns about her client, enhancing the therapist’s abilities to customize a blend to meet the needs of the client. The client is then given a full-body massage with the blend created for her. The massage is relaxing, nourishing, and refreshing. The client is relaxed and feels taken care of. All the while a waft of aroma lingers around the room, mesmerizing the client, adding to the relaxation.

On a physiological level, inhaling a calming or soothing aroma can stimulate the olfactory system, which sends signals to various parts of the body via the limbic and autonomic nervous systems. This process may result in measurable changes, such as decreased blood pressure, relaxation of smooth muscles in the digestive tract, slowed respiration, and reduction of muscle tension.

Simultaneously, the psychological impact of scent can be profound. The close connection between the olfactory system and the limbic system, which is involved in processing emotions and memories, allows aromas to evoke specific emotional responses. Exposure to certain scents may promote feelings of peace, joy, happiness, and nourishment, contributing to an overall sense of well-being and emotional balance.

Phase Two: Lock and Key Mechanism

After the session, the therapist provides the remaining blend for the client to take home. Hours or days later, the client will be able to smell the blend her therapist made for her, and the client will respond as if she were with the practitioner; she will experience relaxation or excitation as dictated by the initial experience. The potential benefits of this memory-based association are far-reaching as it will allow the client to access the state of relaxation and comfort that were originally felt during a massage session.

Experience + Emotion + Aroma = Memory (lock)
Aroma (key) = Memory, experience, emotion

The sense of smell and memory are intricately connected through a fascinating process known as the lock and key mechanism. When an individual experiences a particular event or moment that evokes a strong emotional response, the associated aroma present during that time becomes deeply intertwined with the memory itself. This unique combination of experience, emotion, and aroma creates a powerful sensory imprint, essentially forming a “lock” (memory) within the brain. In the future, when the individual encounters that same aroma again, it acts as a “key,” unlocking the stored memory and its accompanying emotions and sensations, including the effects on the autonomic nervous system.

This phenomenon can have profound effects on an individual’s state of mind and physiological responses. For instance, if the original experience was one of relaxation and tranquility, the re-exposure to the aroma can trigger a similar state of calmness, leading to an increase in parasympathetic activity and a reduction in stress levels.

The lock and key mechanism relies on the brain’s remarkable ability to form and maintain long-term memories associated with specific aromas or combinations thereof, allowing individuals to revisit and relive past experiences through the power of scent.

Creating a therapeutic memory-based association for your clients or self

The aroma used to “condition” should be a scent that does not have memories already attached to it; a neutral or novel aroma is the best. Use aromas that the client perceives as pleasant. A pleasant aroma + a pleasant experience = aroma is perceived as more pleasant and hence more therapeutic.

What determines our general reaction to a particular aroma?

Aromas do not, by definition, have a positive or negative influence, nor does a specific aroma, by definition, elicit a specific mood. Smell-evoked emotions or behavior evolve out of experiences that occur in the presence of those aromas. To have meaning, an individual must develop a relationship with the aroma based on associations and actual experiences. Some factors that determine our general reaction to a particular aroma or smell include:

1. Previous experience with that aroma or one of a similar aroma
2. Our current emotional state when exposed to the odor/aroma
3. Whether the aroma is perceived as pleasant or unpleasant
4. Any auto-suggested relations (e.g., this oil is known to be relaxing or anxiety relieving) and, most importantly,
5. The environment in which the aroma is introduced.

In Practice: Aromatic Memories

Aromas can stir up lost memories and emotions. In fact, memories attached to a particular aroma/smell are considered to be some of the longest-lasting forms of memory. For example, the smell of apple pie baking may remind you of being at home with your family, and you may feel comforted by this aroma. On the other hand, the smell of an antiseptic-type aroma may remind you of being in a hospital when you or someone in your family was sick. Memories can have both positive and negative connotations. Take a moment to reflect on memories and emotions you have that are related to a specific aroma or smell.

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Watch Videos:

 

Olfaction: Structure and Function

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INTRODUCTION

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Our Sense of Smell

Introduction: An Underappreciated Sense

Smell, or olfaction, is one of our oldest and most vital senses, yet it often gets overshadowed by sight and hearing. From the moment we’re born, our sense of smell shapes our experiences, guides our behavior, and creates lasting memories. The word “scent” itself comes from the French “sentir“, meaning to feel or smell. In this lesson, we’ll explore the fascinating development, functions, and significance of the human olfactory system.

From Womb to Adulthood: The Development of Smell

Did you know that our sense of smell starts developing before we’re even born? While growing in the womb, our olfactory system begins taking shape, allowing us to experience the first hints of the world. Newborn babies can already respond to various scents and recognize their mother’s unique smell.

As we grow, our sense of smell keeps developing and refining. Infants and children learn to distinguish different odors and form preferences. Our smelling ability peaks in early adulthood before gradually declining with age, but it remains an essential tool throughout life.

The Many Roles of Smell: More Than Meets the Nose

Over the course of human evolution, our keen sense of smell has become finely tuned for many important reasons:

• Keeping Us Safe: Smell acts as a built-in warning system, alerting us to dangers like spoiled food, smoke, or gas leaks.
• Enhancing Flavor: Smell is closely tied to taste. Delicious aromas stimulate our appetite and guide our food choices, ensuring we eat a varied diet.
• Triggering Memories and Emotions: Certain scents can evoke vivid memories and powerful emotions due to the olfactory system’s close link to the brain’s memory and emotion centers.
• Enabling Social Communication: We each have a unique scent that can convey information about our emotions, health, and compatibility with others. Personal fragrances also serve as a form of self-expression.
• Helping with Navigation: Just as animals use scent trails, humans can use olfactory cues, like the smell of a bakery or coffee shop, to orient themselves and create mental maps.

Olfactory Aromatherapy

Have you ever noticed how certain scents can instantly uplift your mood or soothe your nerves? This is the basis of olfactory aromatherapy – using the sense of smell and the aromas of essential oils to enhance well-being in the mind, body, and spirit. Numerous studies have shown that aromas can produce a wide range of beneficial effects, particularly for stress-related conditions and emotional or psychological issues.

The use of odoriferous matter induces a true sentimental and mental liberation, and essential oils free us from encumbering emotions while leaving our faculties unimpaired.
Marguerite Maury

The magic of olfactory aromatherapy lies in how aromas impact the brain, specifically the limbic system we explored earlier. When we inhale essential oils, the scent molecules travel directly to the limbic regions involved in emotions, memory, and autonomic functions. This can influence our emotional state, nervous system activity, and even hormone release from the endocrine system.

To summarize the benefits of olfactory aromatherapy. Aromatics can be used to:

• Reduce or alleviate stress and anxiety
• Relieve pain by altering pain perception (in the brain)
• Induce sleep or relaxation
• Increase alertness and overall performance
• Support weight control or loss
• Balance and adjust sleep patterns
• Alleviate nausea
• Affect and improve mood and increase overall emotional well-being
• Ease physical ailments, particularly stress-related disorders
• Help shape our impressions of self and others.

FACTS ABOUT THE SENSE OF SMELL

• The sense of smell is very underestimated. Smell is our first primary defense mechanism. Our reaction to smell is quicker at 0.5 seconds than to pain at 0.9 seconds, although we react more quickly to auditory stimuli at 0.15 seconds (Genders).
• The average healthy person can distinguish between ten and forty thousand odors (ad infinitum), many on a subliminal level.
• Smell relays messages from our outer world directly to the brain, influencing the physical body, mind, and emotions.
• Olfactory nerve cells regenerate every thirty to sixty days, clearly underlining their importance.
• Olfaction is a chemical sense; the receptors respond to chemical stimuli. To arouse sensation, a substance must first be in a gaseous state before going into a mucous solution.

Before moving into the anatomy of our sense of smell, let’s take a quick look at the types of olfactory disorders.

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DISORDERS OF OLFACTION

Our sense of smell is a vital part of our daily lives, helping us enjoy the world around us and warning us of potential dangers. However, when this sense is impaired, it can significantly impact our quality of life. In this lesson, we will explore the different types of olfactory disorders, their causes, and the available treatment options.

Types of Olfactory Disorders
There are two main types of olfactory disorders: quantitative and qualitative. Quantitative olfactory disorders affect the strength of a person’s sense of smell. They can be caused by head trauma, viral infections of the upper respiratory tract, or nasal/sinus disease. Quantitative olfactory disorders are the most common type, affecting up to one-fifth of the general population.

Quantitative impairments include:

1. Hyperosmia: An oversensitivity to odors
2. Hyposmia: Reduced sensitivity to odors
3. Anosmia: Complete or nearly complete loss of the sense of smell

In contrast, qualitative olfactory disorders cause a distortion in the perception of odors rather than a reduced ability to smell. These disorders are less common than quantitative disorders, affecting an estimated 4% of the population for parosmia and 0.8% to 2.1% for phantosmia. Qualitative disturbances often occur along with quantitative reductions in the sense of smell.

Qualitative impairments include:

1. Parosmia: An odor is perceived differently than it should be, often unpleasantly, in the presence of an odor source
2. Phantosmia: Perception of an odor that isn’t actually present

Causes of Olfactory Disorders

There are several common causes of olfactory dysfunction, including:

1. Aging: As we get older, our sense of smell naturally declines.
2. Upper respiratory tract infections: Viral infections, such as the common cold or flu, can damage the olfactory receptors in the nose.
3. Traumatic brain injury: Head injuries can damage the olfactory nerves or the brain regions responsible for processing odors.
4. Chronic rhinosinusitis: Inflammation of the nasal passages and sinuses can obstruct airflow and prevent odors from reaching the olfactory receptors.
5. Neurodegenerative disorders: Conditions such as Parkinson’s disease and Alzheimer’s disease can affect the brain’s ability to process olfactory information.
6. Exposure to toxins: Certain chemicals, such as pesticides or solvents, can damage the olfactory system.
7. Medications: Some medications, such as antibiotics or antihistamines, can alter the sense of smell as a side effect.

Diagnosing Olfactory Disorders

If you suspect that you have an olfactory disorder, it is essential to consult with an otolaryngologist (ear, nose, and throat doctor). They will perform a thorough examination and may conduct smell tests to assess your olfactory function. These tests typically involve presenting you with various odors and asking you to identify or detect them.

Treatment Options

The treatment for olfactory disorders depends on the underlying cause. In some cases, the sense of smell may return naturally once the cause is addressed, such as when an upper respiratory infection resolves. Other treatment options include:

1. Olfactory training: This involves regularly exposing yourself to a set of specific odors to stimulate the olfactory system and promote recovery.
2. Medications: Steroids or antibiotics may be prescribed to reduce inflammation or treat infections that are causing the olfactory dysfunction.
3. Surgery: In cases where nasal obstructions, such as polyps, are blocking airflow, surgical intervention may be necessary.
4. Counseling: Adapting to life with an olfactory disorder can be challenging, and counseling can help you develop coping strategies and improve your overall quality of life.

Olfactory disorders can have a significant impact on our daily lives, affecting our enjoyment of food, our ability to detect potential hazards, and our social interactions. By understanding the different types of olfactory disorders, their causes, and the available treatment options, we can better manage these conditions and maintain a good quality of life.

Olfactory Fading and Fatigue

• Olfactory fading occurs when our olfactory system adapts to a smell and ceases to register the aroma. An example of olfactory fading would be the smell of our own home that we grow accustomed to and, therefore, cease to register how it actually smells.
• Olfactory fatigue, on the other hand, is what happens when our olfactory system is exposed to numerous odors within a short span of time. During fatigue, we are no longer able to distinguish between one odor and another. This is when it is time to get a good whiff of coffee beans, as they help to clear the nasal palate, so to speak.

Exercise Your Sense of Smell

The sense of smell, like muscles and the brain, needs exercise to become stronger. Often, when someone thinks they don’t have a good sense of smell, it is because they don’t consciously use it. Also, some individuals don’t like the smell of essential oils at first, and often, this is because they have been brought up on synthetic odors and are used to the way synthetics smell. More often than not, however, when that same individual begins to exercise their sense of smell and become more familiar with the natural aromas of essential oils, they begin to experience the vast differences between synthetics and natural aromas.

To exercise the sense of smell, begin by simply observing different aromas/smells within your environment. Then, move on to smelling plants when they are in bloom or natural, authentic essential oils. Take time to truly experience the nuances of an aroma. You could even keep a journal of all the different aromas you observe. Share your experiences with others.

The Power of Smell Training
See Blog Post here: https://aromaticstudies.com/the-power-of-smell-training/

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Aromatic Waters: Hydrosols

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Watch: About Hydrosols with Jade Shutes & Ildiko Berecz

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The word “hydrosol” is derived from the Greek hydro, meaning water, and the Latin sol, meaning solution. When plant matter is distilled, an essential oil and a hydrosol are produced.

Hydrosols, also known as hydrolats, are the aqueous product of distillation. They carry the hydrophilic (water-soluble) components of the plant in solution, as well as microscopic droplets of essential oils in suspension.

Every liter of hydrosol contains between 0.05 and 0.2 milliliters (less than 1%, typically 0.01 – 0.04%) of dissolved essential oil, depending on the water solubility of the plant’s components and the distillation parameters. Hydrosols also contain carboxylic acids, which may explain their observed anti-inflammatory activity.

Hydrosols are sometimes called flower or floral waters. This term is imprecise: Not all hydrosols are made from flowers, and most hydrosols do not have a floral aroma. Hydrosols, like essential oils, can be made from leaves, whole plants, seeds, roots, flowers, and resins. Unlike essential oils, hydrosols can also be produced from non-aromatic plants such as nettles or plantain.

When water and essential oils are mixed for the purpose of spraying into the air, with or without a dispersing agent, this would be called an aromatic spritzer, and its therapeutic benefits and safety concerns will be slightly different from that of a true hydrosol.

Hydrosols may be used in/for:

• Hydrotherapy (baths)
• Aromatic sprays
• Compresses
• Clays
• Internal applications
• Gels, lotions and creams
• Toners and cleansers

Hydrosols, like essential oils, can be combined together for a variety of different therapeutic purposes.

Hydrosols as hydrating agents:

Modern skin suffers tremendously at the hands of environmental conditions, excessive coffee use, low water intake, and nutritional deficiencies. When the skin is in need of hydration, besides consuming water internally, the application of hydrosols is incredibly beneficial. Neither essential oils nor vegetable carrier oils contain water and hence are not hydrating to the skin. Hydrosols and all-natural skin care creams are able to deliver the necessary moisture to the skin (along, of course, with dietary measures and increased water consumption).

Integrating hydrosols into Practice:

Hydrosols add a dynamic aspect to blending and applications for aromatherapy. They can be used as single hydrosols or blended together. They can be added to creams, lotions, gels, cleansing bases, and other products that accept a water component. Hydrosols are often used as toners and as additions to bath water.

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Dilution Rates:

• For concentrated creams, lotions, gels, and cleansing bases: add hydrosols 1tsp or tbsp. at a time until the desired consistency is achieved.
• For handmade creams/lotions: use hydrosol/s in place of water.
• For baths: For babies up to six months add 1 teaspoon of chosen hydrosol to an infant bathtub or 2 teaspoons for an adult tub filled to baby depth. For children up to twelve years of age, add 1 teaspoon of hydrosol per year of age, up to a maximum of 8 teaspoons. Adults can use from 30 to 250 milliliters (or 1 to 8 ounces per tub).1 Add 2-3 tbsp for foot bath.
• For compresses: For adults add 3 to 5 tablespoons of hydrosols to l liter of water at the desired temperature; for children add 2 to 3 teaspoons of hydrosols per 1 liter of water.
• To use as toner: combine one or more hydrosols together. You can add in a small amount (1-2tbsp. per 2 ounces) aloe vera gel, aloe vera gelly, and/or honey as well.
• For gels, clays, and cleansers: use amount based upon desired consistency.
• Internal use: add 1-2 tbsp in a glass of water. (e.g. Neroli/Orange flower hydrosol can be quite beneficial for reducing coffee jitters, and 1-2 tsp of German chamomile hydrosol for a child over 3 years old can be quite beneficial in helping the child to sleep.)

Hydrosols and Their Therapeutic Benefits

Hydrosol	Therapeutic Benefits
German chamomile Matricaria recutita Stable: can last up to two years pH: 4.1	● #1 hydrosol for infants and young children: diaper rash, calm and soothe, and help with sleeping ● Anti-inflammatory and cooling properties make it useful for various skin conditions, such as eczema, psoriasis, rashes, acne, sunburns, and other inflammatory conditions ● Calming and balancing to the autonomic nervous system; soothes or reduces feelings and symptoms of stress ● German chamomile, like lavender, can be added to the bath for its sedative and soothing properties
Roman chamomile Chamaemelum nobile Stable: can last up to two years pH: 3. - 3.3	● Calming and soothing effects on the mind: insomnia, stress relief, mildly euphoric ● Anti-inflammatory and antiseptic for the skin: rashes, acne ● Beneficial for reducing anxiety, anger, and childhood hyperactivity
Helichrysum Helichrysum italicum Stable: can last up to two years pH: 3.5 - 3.8	● Anti-inflammatory and cooling properties make it useful for various skin conditions, such as eczema, psoriasis, rashes, acne, sunburns, and other inflammatory conditions ● Useful for dry, mature skin.
Lavender Lavandula angustifolia Stable: can last up to two years pH: 4.6 - 5.9	● Relaxing, soothing, and comforting: headaches, stress-related conditions ● Anti-inflammatory and antiseptic ● For infants in the bath or as a spritzer for diaper rash, sleep problems ● Muscular aches and pains, sprains, strains, sore or stiff muscles
Neroli / Orange flower Citrus aurantium var. amara Stable: can last up to two years pH: 3.8 - 4.5	● Antidepressant, euphoric ● Stress relieving, insomnia, mild sedative ● Toner for acne and oily skin due to mild astringent effect
Rose Rosa damascena Stable: can last up to two years pH: 4.1 - 4.4	● Astringent, useful for acne, varicose veins, oily skin, normal-to-dry, mature, sensitive, and devitalized skin ● Calming, soothing, nurturing ● Strong affinity with the heart, useful for individuals who are grieving or are in need of emotional support, heartache ● Female tonic: cramps, PMS symptoms, emotional upsets, hot flashes, menopause symptoms and related skin conditions
Witch hazel Hammamelis virginiana Moderate shelf life: 8-12 months pH: 4.0 - 4.2	● Astringent, useful for acne, varicose veins, oily skin, normal-to-dry, mature, sensitive, and devitalized skin ● Strongest antioxidant hydrosol (Catty, 2001) ● Cracked or blistered skin, eczema, psoriasis ● Hemorrhoids ● Reduces itching, rashes, inflammation, and swelling of the skin

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Recipe Ideas:

Cleanser for Oily Skin

Just under 2 ounces Castile soap – leave enough space to add the following:

• 1 tbsp Witch hazel hydrosol
• 1 tbsp Glycerin
• 10 drops Cypress e/o
• 10 drops Lavender e/o

Gel for Burns

Just under 2 ounces concentrated gelly – leave enough space to add the following:

• 2 tsp Lavender hydrosol
• 2 tsp German chamomile hydrosol
• 2 tsp Calendula herbal oil
• 14 drops Lavender e/o
• 10 drops Helichrysum e/o
• 7 drops Roman chamomile e/o

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CARRIER OILS IN PRACTICE

Carrier oils are a vital, intrinsic part of the repertoire of aromatherapists and botanical body care product manufacturers. The term “carrier” oil indicates the oils’ usefulness as vehicles for therapeutic plant extracts, but they are also unique, therapeutic substances with astounding benefits for holistic skin care.

Carrier oils are primarily comprised of two major categories, the fixed – or vegetable – oils, and herbal oils, which is where herbs are infused into a fixed oil. Essential oils can then be added to any of these carrier oils, thereby increasing the therapeutic value of the overall blend. This combination of essential oils and carrier oils, either fixed oils or herbal oils, offers an ideal therapeutic partnership.

Carrier oils can be obtained from fruits (e.g., olive, sea buckthorn), seeds (e.g., raspberry seed, pomegranate seed), or nuts (e.g., walnut, hazelnut, shea nut butter). The main components of carrier oils are triglycerides (92-98%) and complex mixtures of minor compounds (2-5%) including sterols, wax esters, squalene, tocopherols, pigments, phospholipids, and phenolic components. The types and proportions of these components contribute to the viscosity of the oils, so the carrier “oils” also include the semi-solid butters (e.g., shea nut butter) and waxes (e.g., beeswax).

For aromatherapy, we use carrier oils in:

1. Oil based products for the body or face
2. Oil based products for the hair
3. Handmade creams or lotions
4. Concentrated gels (e.g. aloe vera gelly)
5. Salve preparations
6. Lip balms
7. Body butters and ointments (not covered in this course)
8. To make herbal oils

What are the therapeutic benefits of carrier oils?

The therapeutic activities of carrier oils in this palette are to:

• support and maintain the skin’s intercellular lipid matrix, which in turn serves to protect the integrity of the stratum corneum and its barrier function
• prevent transepidermal water loss (TEWL) by forming an occlusive film on the surface of the skin
• restore barrier function, if damaged
• provide antioxidant activity (preventative to aging)
• provide anti-inflammatory activity

Carrier Oil Production: Methods of Extraction

There are several methods for extracting vegetable oils, from mechanical extraction to microwave-assisted extraction. In this book, we cover the most common methods, which include:

• Cold Pressing or Expeller Pressing: The oil is pressed using a mechanical screw press at temperatures between 45-49 degrees F. The extraction process may include enzymes to increase yield. Still, the oil yield from cold pressing tends to be lower than the yield from solvent extraction. The CODEX Alimentarius Standards define “cold pressed oils” as “obtained, without altering the oil, by mechanical procedures only, e.g., expelling or pressing, without the application of heat. They may have been purified by washing with water, settling, filtering and centrifuging only.”

The CODEX further defines “virgin” as “obtained, without altering the nature of the oil, by mechanical procedures, e.g., expelling or pressing, and the application of heat only. They may have been purified by washing with water, settling, filtering and centrifuging only.”

• Solvent Extraction: This method of oil extraction, which uses a solvent, such as benzene, to extract lipids from nuts and seeds, is a more efficient form of extraction, producing greater oil yields.

• Supercritical Fluid CO2 Extraction: CO2 extraction uses supercritical carbon dioxide, which has the properties of both a gas and a liquid, to extract specific compounds from a plant. Various industries have used this technique for many years (for instance, for decaffeinating coffee,) but it is relatively recently that aromatherapists have used CO2 extracts as therapeutic agents. CO2 extracts from seeds include lipids and can function as carrier oils.

The supercritical CO2 extraction process can be very precise, allowing the producer to select specific molecules to be included in the final product, potentially increasing the oil’s therapeutic value. The carbon dioxide evaporates at the end of the process, leaving no residues behind in the final product. The carbon dioxide can also be fully recycled, making this extraction method relatively environmentally friendly.

How Refining Affects Quality

Refining puts the extracted fixed oil through additional processes to “purify” it. These processes remove undesirable pigments, odor, taste, and fatty acid oxidation products, such as peroxides and their degradation products. The refining process removes many of the nutritive-rich components to lengthen shelf life.

Food producers use the refining process to make oils suitable for consumption and increase their shelf lives. Unfortunately, these processes cause the loss of valuable nutrients, essential fatty acids, and natural antioxidants, producing oils with little to no therapeutic value. Many supermarket oils fall into this category.

Some companies selling carrier oils for aromatherapy and cosmetics will list the oils with RBD or RBDW after the name of the carrier oil, for example, Apricot Kernel – RBD or Black Currant Seed – RBDW. RBD stands for “Refined, Bleached, and Deodorized.” RBDW stands for “Refined, Bleached, Deodorized, and Winterized.” What do the terms refined, bleached, deodorized, and winterized mean?

• Bleaching: The purpose of bleaching is to remove the color pigments from the oil. Bleaching also removes components of the oil that contribute to the oil’s oxidation rate. The bleaching process combines the oil with a bleaching clay (a natural clay or activated with an acid wash) and heats it to high temperatures. The clay absorbs and removes undesirable components, such as the unwanted color pigments. Once the bleaching process is complete, the oil is filtered to remove the clay and other particulate matter, and the resultant oil is nearly colorless.
• Deodorizing: Deodorizing an oil removes the flavor and aroma of the oil by passing steam through it to remove the undesirable components, leaving an oil with no taste or smell.
• Winterizing: Winterization removes compounds, such as waxes, that crystallize at low temperatures and can cause an oil to become cloudy. The process occurs in three steps: heating the oil, appropriate cooling to crystallize undesirable components, and finally, filtering to remove these crystallized components. Winterization typically happens before the deodorizing.

Major Components of Carrier Oils: The Fatty Acids

There are three categories of fatty acids found in carrier oils:

1. Saturated fatty acids – Saturated fatty acids (SFAs) contain the maximum possible number of hydrogen atoms attached to every carbon atom, and the molecule is therefore said to be “saturated” with hydrogen atoms. Saturated fatty acid oils are solid at room temperature. Examples of oils rich in saturated fatty acids include coconut oil and palm kernel oil.
2. Monounsaturated fatty acids – Monounsaturated fatty acids (MUFAs) are fatty acids that contain two neighboring hydrogen atoms somewhere in the chain, resulting in one double bond between two carbon atoms. One of the most common monounsaturated fatty acids is oleic acid which is relatively abundant in olive, canola, sunflower (high oleic acid version), and safflower oils.
3. Polyunsaturated fatty acids – Polyunsaturated fatty acids (PUFAs) are fatty acids with two or more carbon double bonds. Two of the most important polyunsaturated fatty acids are alpha-linolenic acid and linoleic acid. These two fatty acids are considered to be Essential fatty acids (EFAs), as they are absolutely essential for human health, but the human body cannot synthesize them; we must either consume them in our diets or apply them to our skin.Polyunsaturated fatty acids are very unstable and can easily oxidize if exposed to oxygen and light. The presence of tocopherols in oils rich in PUFAs may contribute to their lipid stability.

Please note: In this section, we cover the most common fatty acids found in carrier oils. We cover a lot more in our new book, The Carrier Oil Palette.

Saturated Fatty Acids

• Lauric acid (12:0)
• Myristic acid (14:0)
• Palmitic acid (16:0)
• Stearic acid (18:0)

→ Lauric acid
Lauric acid is a major component of coconut and palm kernel oils. An in vivo study showed the antimicrobial properties of lauric acid against Cutibacterium acnes (syn. Propionibacterium acnes,) indicating its potential use in cases of acne vulgaris.

→ Myristic acid
Myristic acid is a minor component of coconut and palm kernel oils.

→ Palmitic acid
Palmitic acid is the most common saturated fatty acid in the human body, accounting for 20–30% of the total fatty acids. One of its key roles is to create a protective coating on the surface of the skin. It is also found in palm oil (44%), sea buckthorn oil (34-35%), cocoa butter (26%), olive oil (8-20%), macadamia nut oil, and meat and dairy products (50-60%). (Percentages are based on total fat content.)

→ Stearic Acid
Stearic acid, one of the most commonly occurring fatty acids, is a saturated fatty acid found in both animal and vegetable fats and oils, including beef fat and cocoa butter. It is found in abundance in tallow (38%), cocoa butter (33-40%), and shea nut butter (25-50%). It is a minor component in coconut and palm kernel oils.

Stearic acid is used in the manufacture of pharmaceutical products as a delivery system and for masking the bitter taste of pharmaceutical compounds. Isolated stearic acid is used in creams as a thickening and emollient agent.

Note: If you are purchasing isolated stearic acid, make sure to purchase either organic steric acid or regular steric acid that is plant-derived, not animal fat-derived.

Monounsaturated fatty acids

• Palmitoleic acid (16:1 n7)
• Oleic acid (18:1 n9)

→ Palmitoleic acid
Palmitoleic acid, an omega-7 fatty acid, is a promising anti-inflammatory MUFA that may help to ameliorate metabolic disorders when used as a dietary supplement. Although it is uncommon in plants, it is a component of skin lipids and supports the regeneration processes required for wound healing in the epidermis. In vivo and in vitro trials support palmitoleic acid in the treatment of vaginal atrophy, skin hyperpigmentation, wound infections, diabetes, and liver dysfunctions.

Palmitoleic acid is found in significant amounts in sea buckthorn oil (34-36%).

→ Oleic acid (Omega-9)
Oleic acid is probably the most commonly found fatty acid in vegetable oils; the most common human food sources are almond, olive (upwards of 78%), macadamia, high oleic sunflower and safflower, grapeseed, sesame, palm, rapeseed, soybean, butter, lard, and tallow. Carrier oils with a high content of oleic acid, such as olive oil (60-70%), are more resistant to the damaging effects of heat and light.

Oleic acid has been found to be fungistatic against a wide spectrum of saprophytic molds and yeasts. Oleic acid has also demonstrated the ability to penetrate the dermal-epidermal junction in a dose-dependent fashion, which can result in increased TEWL, as well as increased skin penetration of other oil constituents. Balancing oleic acid content with other fatty acids can mitigate concerns associated with this increase in TEWL.

Studies have shown oleic acid and lauric acid to be effective skin penetration enhancers by disrupting the lipid structure of the stratum corneum. One study showed that oleic acid optimizes cutaneous delivery of Lumiracoxib (LM), a non-steroidal COX-2 selective inhibitor anti-inflammatory drug, by significantly increasing drug retention in both the epidermis and the dermis. This activity ensures the drug moves continuously and consistently through the skin.

Another study showed that unsaturated fatty acids, specifically omega-9 fatty acids (oleic acid), modulate the inflammation in wounds and enhance the reparative response in vivo. Oleic acid-containing carrier oils may, therefore, be useful in treating cutaneous wounds.

Polyunsaturated fatty acids

• *Linoleic acid (18:2 n6)
• *Alpha-linolenic acid (18:3 n3)
• Punicic acid (18:3 n5)
• Gamma linolenic acid (18:3, n6)

Polyunsaturated oils are highly susceptible to oxidation. *Two of the polyunsaturated oils, alpha-linoleic acid and linoleic acid, are considered essential fatty acids (EFAs), making them especially important. Dietary consumption of PUFAs can be used in the prevention of a number of human diseases, many of which are associated with excess inflammation.

→ Linoleic Acid (Omega-6) (LA)
Linoleic acid is a polyunsaturated essential fatty acid (PUFA) of the omega-6 series, that is important in building the membranes that surround every skin cell. It is necessary to the proper growth and development of the epidermis and is required for synthesis of the important long-chain ceramides necessary to protect against dry skin.

The presence of linoleic acid within the lipid matrix of the stratum corneum plays a core role in maintaining the water-permeability barrier of the skin, prevents the skin from peeling, prevents TEWL, improves the softness of the skin, improves the skin’s elasticity, and regulates the process of epidermal keratinization.

Linoleic acid also displays antibacterial activity and improves the functioning of sebaceous glands in oily or problematic skin types, thereby unblocking pores and reducing the formation or number of blackheads. It can also play a role in cellular regeneration and moderating inflammation.

A deficiency of linoleic acid in the skin can lead to its replacement by oleic acid thereby negatively impacting the skin’s barrier function and increasing TEWL. This lack can further lead to other serious skin problems, such as premature skin aging associated with a reduction in the strength of the skin’s supporting collagen fibers, which may also slow wound healing. It may also trigger hair loss. Dietary deficiency of linoleic acid results in a characteristic scaly skin disorder and excessive epidermal water loss.

Carrier oils rich in linoleic acid include safflower, sunflower (not high oleic acid version,) flax seed, hemp seed, wheatgerm, walnut, and sesame oil.

→ Alpha-linolenic acid (Omega-3) (ALA)
Alpha-linolenic acid, another essential fatty acid, is highly concentrated in flaxseed oil and to a lesser extent in sea buckthorn seed, canola, soy, perilla, and walnut oils. When ingested, the body converts ALA to eicosapentaenoic acid and docosahexaenoic acid both of which are also omega-3 fatty acids. Omega-3 fatty acids help to reduce inflammation. Applied topically, alpha-linolenic acid reduces inflammation and may be beneficial for chronic inflammatory skin conditions.

→ Gamma linolenic acid (Omega-6) (GLA)
One of the fatty acids derived from linoleic acid is gamma linolenic acid (GLA). GLA plays an important role in the formation of prostaglandins, which, in turn play an important role in the inflammatory process, blood clotting, stimulating smooth muscle in the uterus, inhibiting the secretion of gastrointestinal acid, and increasing the secretion of a protective mucous layer in the stomach. A deficiency of GLA can lead to a variety of inflammatory, autoimmune, and other disorders.

Carrier oils rich in gamma linolenic acid may play an important role in treating inflammatory conditions including eczema, atopic dermatitis, acne, psoriasis, and rheumatoid arthritis. Hemp seed oil and GLA appear to alleviate symptoms of atopic dermatitis and other skin diseases. GLA has also serves as an emollient for the skin and mucous membranes both internally and externally. Apart from human breast milk, evening primrose oil, black currant seed oil, hemp seed, and borage seed oil are the main sources of GLA, although it is also found in trace amounts in green leafy vegetables.

Fat-soluble Vitamins and Nutrients found in Carrier Oils
(mostly unsaponifiable fraction)

→ Phytosterols
Sterols, natural components present in many plants and animal species, are also essential for human and animal health. The richest natural sources of plant sterols in the human diet are unrefined vegetable oils, seeds, nuts, and legumes. Phytosterols are similar in structure and function to cholesterol, a lipid naturally found in human skin where it has a water-binding capacity and is very important in repairing damaged skin barrier function. Sterols in carrier oils, which do not include cholesterol, may play similar roles when applied to human skin. Carrier oil phytosterols are also useful in reducing inflammation for such skin conditions as skin eruptions, eczema, and itchy skin.

In plant oils, the composition of phytosterols may vary due to plant species, agronomic and climatic conditions, extraction and refining procedures, and the quality of the fruits or seeds.

Although phytosterols are minor components of carrier oils, they comprise the major portion of the unsaponifiable fraction and generally account for about 1% of the oil. The average content of sterols is between 142.64-1891.82mg/100g oil.

Phytosterols possess a variety of bio-actions that have been implicated in slowing the pathogenesis of chronic disease, demonstrating antioxidant and anti-inflammatory activity as well as the capacity to promote detoxification, reduce cell proliferation, and/or lower serum low-density lipoprotein (LDL) cholesterol. Sterols are generally considered to be heat-stable, odorless, and tasteless.

The main phytosterols found in carrier oils are:

• beta-sitosterol
• Stigmasterol
• Campesterol
• delta-5-avenasterol

Beta-sitosterol (BSS) is the major phytosterol found in higher plants. In animals, BSS has been shown to exhibit anti-inflammatory, anti-pyretic, anti-neoplastic, and immune-modulating activity. It is also a known antioxidant, able to reduce DNA damage and the level of free radicals, in addition to possibly increasing the level of typical antioxidant enzymes.

→ Squalene
Squalene, a triterpene, polyunsaturated hydrocarbon, derives its name from the shark, whose liver oil contains the richest source of squalene. In humans, squalene makes up between 10-14% of sebum. In carrier oils, olive oil contains one of the highest amounts of squalene at 0.2-0.7%.

Squalene shows some advantages for the skin as an emollient, antioxidant, and for its antitumor activities. Squalene appears to be highly effective for reducing free radical oxidative damage to the skin, as well as effectively inhibiting chemically induced skin, colon, and lung tumorigenesis in rodents. Truly one of nature’s great emollients, squalene is quickly and efficiently absorbed deep into the skin, restoring healthy suppleness and flexibility without leaving an oily residue.

Squalene is used as a material (contained in carrier oils) or additive (isolated ingredient) in topically applied vehicles such as lipid emulsions, creams and lotions.

→ Tocopherols/Vitamin E
The vitamin E family, often referred to as “tocopherols,” includes alpha (α), beta (β), gamma (γ), and delta (δ) tocopherols, named here in order of their biological importance. Alpha-tocopherol is considered by some to be the most biologically active. Carrier oils may contain between 200-800 ppm of tocopherols.

Vitamin E is yet another nutrient that humans cannot synthesize and therefore must acquire from plants. It is one of the most important and potent antioxidants, which means that it is able to prevent cell damage from the destructive elements of free radicals, found in carrier oils. Free radicals, when in excess, can damage healthy tissue, destroy the collagen and elastin fibers that support the skin, and interfere with the formation of fresh, healthy skin cells, resulting in aging of the skin and making complexions blotchy and dull.

Vitamin E also helps to protect the skin against environmental pollutants. Vitamin E assists wound healing and has great repairing and regenerating properties. It is used topically to reduce scar formation and to treat burns, including radiation burns. In conjunction with beta-carotene, vitamin E decreases the harmful effects of the sun and photoaging.

One research study showed that vitamin E levels in the upper layers of the stratum corneum drop significantly after even a brief exposure to sunlight, but this can be remedied by a topical application of vitamin E in the form of a body wash (used in this study.) This topical application was also more effective at replacing the vitamin E in the skin than use of a dietary supplement.

Studies have shown that alpha-tocopherol provides a highly protective antioxidant activity in the skin and concentrations ranging from 0.1 to 1% are likely to be adequate to provide effective skin barrier protection. Vitamin E can be added to carrier oils as an isolated component to prevent oxidation of beta-carotene and vitamin A.

→ Vitamin A
Vitamin A is the name of a group of fat-soluble retinoids, including retinol, retinal, retinoic acid, and retinyl esters. Dietary vitamin A is involved in immune function, vision, reproduction, and cellular communication. Two forms of vitamin A are available in the human diet: preformed vitamin A (retinol and its esterified form, retinyl ester) and provitamin A carotenoids. Preformed vitamin A is found in foods from animal sources, including dairy products, fish, and meat (especially liver). By far the most important provitamin A carotenoid is beta-carotene.

One study found that naturally aged, sun-protected skin and photoaged skin have important molecular features in common, including connective tissue damage, elevated matrix metalloproteinase levels, and reduced collagen production. Topical application of a 1% vitamin A solution for 7 days improved all of these indicators in both naturally aged and photoaged skin. Some symptoms of vitamin A deficiency include rough, dry, scaly skin; problems with gums and teeth; loss of smell and appetite; and night blindness.

Toxicity: Large dietary intake of vitamin A for long periods of time can lead to hypervitaminosis (excessive vitamin intake) with symptoms such as nausea, headache, vomiting, skin discoloration, excessive skin drying, and more.

→ β-carotene (Beta-carotene)
Beta-carotene is one of over five hundred carotenes that occur in nature. Beta-carotene, a precursor to vitamin A, is considered to be one of the most active of the carotenes. It is a potent scavenger of toxic oxygen radicals, especially those produced by chemicals in the air and those generated by our own metabolism. It has stronger immune-stimulating and thymic supportive activity than vitamin A.

Oils rich in beta-carotene, such as carrot herbal oil, palm oil, and sea buckthorn oil, tend to be a rich orange color. Palm oil also contains the carotene lycopene, which, like b-carotene, exhibits anticancer abilities.

Beta-carotene can accumulate in the skin as a result of dietary supplementation. It acts as a photoprotective agent in the skin, as it functions as a cellular screen against sunlight-induced free radical change. However, as with vitamin A, higher doses (15mg/day) and long-term usage (8 weeks) can be harmful.

→ Vitamin D
Vitamin D, sometimes called “the sunshine vitamin,” works with calcium to build strong, healthy bones and teeth. New evidence suggests that vitamin D also plays a role in cell proliferation and maturation.

→ *Lecithin
*As a phospholipid, lecithin is part of the saponifiable fraction.

Lecithin is a phospholipid commonly derived from egg yolk or soy oil. The name “lecithin” is derived from the Greek word likithos, meaning egg yolk. In the human body, lecithin is an important component of cellular membranes, particularly those of the brain and nerves. It is also a strong, natural emulsifying agent often used in food products, cosmetics like creams and lotions, and many transdermal drug delivery systems. Since lecithin is an integral part of cell membranes it is considered highly biocompatible and is indicated for psoriasis and eczema.

Lecithin is removed from some carrier oils by a process called “degumming.” Main carrier oils from which lecithin is extracted are soybean oil, rapeseed oil, and sunflower seed oil. Note: Because lecithin is produced from soy (a heavily genetically modified crop), it is very important to purchase only organic lecithin or sunflower lecithin, when using as an individual ingredient.

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Watch About Essential Oils and the Skin with Jade

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Aromatherapy and the Skin

Since being trained as an aromatherapist over 32 years ago, aromatherapy has grown tremendously in the field of skin care. A variety of research on the therapeutic benefits of essential oils supports their application and benefit for a wide range of skin conditions.

Essential oils are able to:

• reduce inflammation,
• enhance/support wound healing,
• treat fungal, bacterial, and viral infections,
• support and enhance the health of the skin,
• relieve itching,
• support healthy scar tissue formation,
• prevent wrinkles and slow the aging process,
• support the detoxification process,
• serve as penetration enhancers, e.g. for such things as water (to increase hydration to the skin)
• And much more.

According to Harris, “Aromatherapists have at their disposal remarkable tools that can simply and positively impact a range of commonly encountered skin conditions responsible for significant psychosocial distress. The aromatherapist is able to work at the level of the cutaneous interface not only through the judicious application of essential oils and their related products but also through touch, olfaction, and stress reduction with their subsequent positive impacts on skin health.”

With such a vast array of therapeutic benefits, it is no wonder that aromatherapy is growing in popularity within the cosmetics and esthetics industries, as well as with individual consumers seeking more natural means of maintaining and supporting the health not only of the skin but of their whole body.

Table 7.1 lists the therapeutic action desired as well as essential oils which exhibit that action. Please note: Only the twenty-four essential oils covered in this course are included.

Table 7.1 Essential Oil Therapeutics for the Skin

Therapeutic Action	Essential Oils
Anti-inflammatory – a substance which soothes and reduces inflammation	Roman Chamomile, Frankincense, Helichrysum, Lavender, Patchouli
Antibacterial – a substance which destroys bacteria	Eucalyptus globulus, Lemongrass, Tea tree
Antifungal – a substance which destroys or inhibits fungal growth	Lemongrass, Patchouli, Tea tree
Antiseptic – a substance which destroys or prevents the growth of microbes	Roman Chamomile, Frankincense, Helichrysum, Lavender, Lemon, Lemongrass, Patchouli, Tea tree
Astringent – a substance which causes cells to shrink; contracts, tightens, and binds tissues	Cedarwood, Rose Geranium, Lemon, Patchouli, Vetiver
Circulatory Stimulant/Tonic – a substance which enhances or increases blood circulation	Eucalyptus, Juniper berry, Laurel, Lemon, Lemongrass, Rosemary ct. camphor or cineole
Cellular rejuvenation – a substance which enhances cellular reproduction	Roman chamomile, Frankincense, Helichrysum, Lavender, Rosemary ct. verbenon
Detoxifier – a substance which enhances the removal of toxic substances from the body	Cypress, Fennel, Grapefruit, Juniper berry, Laurel, Lemon
Nervine/Relaxant - a substance which relaxes the nervous system, can reduce or soothe nervous disorders	Roman Chamomile, Frankincense, Lavender, Mandarin, Patchouli, Sweet orange, Vetiver, Ylang ylang
Vulnerary – a substance which promotes wound healing	Roman Chamomile, Frankincense, Helichrysum, Lavender, Rosemary ct. verbenon

Now let’s have a look at specific essential oils.

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Highlight on Core Essential Oils for the Skin

This section focuses on the specific actions the essential oil has on the skin but it is also of equal importance to appreciate the potential impact the essential oil has on the emotional well-being of the individual as well. Spend some time reflecting on each essential oil and how it can also soothe, uplift, energize, inspire, and relieve stress/anxiety in addition to its specific actions on the skin.

Essential Oil	Indicated for:
Bergamot
Citrus bergamia	acne, weeping eczema, oily complexion, cold sores, oily hair/skin, vitiligo, psoriasis
Roman chamomile
Chamaemelum nobile	Inflamed skin conditions: dermatitis, eczema, psoriasis, hives. Broken capillaries, acne, fungal infections, skin ulcers, slow-healing wounds, razor burn, itchy skin conditions. Abscesses (warm or hot compresses).
Clary sage
Salvia sclarea	eczema caused by stress or anxiety, inflamed skin conditions, mature skin, wrinkles, excessive sebum production, dry itchy skin
Copaiba
Copaifera officinalis	mature skin, wrinkles, scar tissue, wound healing, eczema, acne, atopic dermatitis, inflamed skin conditions, soothing to dry irritated skin, itchy skin
Cypress
Cupressus sempervirens	oily, sweaty skin and feet, broken capillaries, Rosaceae, bruises, cellulite, supportive wound healer, excessive sweating
Eucalyptus
Eucalyptus globulus	herpes simplex, shingles, chickenpox, measles, acne, ulcers, wounds, mycotic infections, boils, burns, cuts
Sweet Fennel
Foeniculum vulgare var. dulce	sluggish, congested, or smoker’s skin (can be beneficial for stimulating microcirculation and detoxification), cellulite, spasmodic cough, fennel hydrosol may be utilized in compresses for conjunctivitis
Frankincense
Boswellia sacra	mature skin, wrinkles, scar tissue, postoperative wound healing (once sutures are removed), eczema, acne, inflamed skin conditions, blackheads, hives, soothing to dry irritated skin
Geranium
Pelargonium sp.	oily skin, hormone-related acne, acne; poor circulation in the skin caused by smoking; ringworm; head lice; dandruff; mouth ulcers, thrush (oral), and gum infections; wound and abscess healing; cellulite; fungal or bacterial infections of the skin; rosacea, cold sore (antiviral), acute or chronic inflammatory skin disorders
Grapefruit
Citrus paradisi	astringent, oily /congested skin, cellulite, water retention, hair loss
Helichrysum
Helichrysum italicum	acne, chronic dermatitis, eczema, scar tissue reduction/to support healthy scar tissue formation, burns, dermal inflammation, cuts and wounds, bruises, radiation burns, Herpes simplex, tissue trauma, broken capillaries, stretch marks, dry itchy skin, varicose veins, rosacea, psoriasis, aging skin
Juniper berry
Juniperus communis	poor elimination, slow healing sores, acne, oily skin, eczema, herpes, oily scalp
Laurel
Laurus nobilis	oily skin, acne, boils, slow-healing wounds, ulcers, pressure sores, fungal infections/mycoses
Lavender
Lavandula angustifolia	burns (recommend using Lavandula latifolia instead or in conjunction with), scrapes, abscesses, acne, athlete’s foot, eczema, inflamed skin conditions, psoriasis (as an anti-inflammatory), sunburn, relieves itching, insect bites, hives, open wounds or sores, poorly healing wounds, allergy (expressed on the skin), razor burn, stretch marks
Lemon
Citrus limon	acne, boils, comedones, premature aging skin (preventative), oily complexions, mouth ulcers, cellulite, herpes, Rosacea (couperose), tired, sagging and grayish (smoker’s) skin, capillary fragility, broken capillaries, varicose veins (can help to prevent and also to prevent them from getting worse)
Lemongrass
Cymbopogon citratus	acne, oily skin, boils, athletes’ foot, cellulite, excessive sweating, ‘has a special tightening effect on the elastin fibers in the corium and in the subcutis’, weakness of connective tissue, applicable to breast treatment (tightening), ringworm **Always dilute down in a vegetable oil or other base before applying to the skin!
Mandarin/Tangerine
Citrus reticulata	cellulite, acne, oily skin, edema
Marjoram, Sweet
Origanum majorana	inflamed skin conditions, wound healing, acne, eczema
Patchouli
Pogostemon cablin	aging or sagging skin, itchy or inflamed skin conditions, acne, athlete’s foot, cracked or chapped skin, eczema (weeping), wrinkles, irritated skin conditions, sores, fissures, inflamed scar tissue, fungal or parasitic skin infections, allergic inflammation, cellulite
Rosemary ct. verbenone
Salvia rosmarinus	rosacea, acne, seborrhea (oily skin with congestion), varicose veins, wound healing, promotes microcirculation, skin care
Tea Tree
Melaleuca alternifolia	acne, nail fungus, oily skin, abscesses, boils, cold sores11, cuts, dandruff, herpes simplex, insect bites, lice, rashes, shingles, infected wounds, varicose ulcers, athlete’s foot, ringworm, inflamed skin conditions, varicose veins, juvenile acne, acne rosacea, prevention of skin radiation burns, dermal mycoses (fungal infections)
Vetiver
Vetiveria zizanioides	acne, inflamed conditions (chronic and acute), oily skin (due to vetiver’s slight astringent effect), preventative for stretch marks and wrinkles, wound care, irritated skin, rashes, and topical bacterial or fungal infections
Ylang ylang
(Cananga odorata)	oily/combination skin, aging or stressed skin, scalp tonic, regulates sebum

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The Skin is a Pathway onto and into the Body

Understanding the skin’s structure and function guides botanical body care formulators in creating effective products. Everything placed onto the skin affects not only the skin cells but potentially the entire physical body.

Holism and the Skin

Before exploring skin anatomy and physiology, let’s consider our own skin holistically. The skin receives nourishment from both our diet and topical products, while also responding to our emotional state through its connection to the nervous system.

The skin provides valuable information about internal and emotional conditions. Common skin conditions like psoriasis and eczema often reflect internal imbalances. Skin problems arise from multiple factors: genetic predispositions, nutrition, hormones, medication side effects, stress, inflammatory processes, and gut health.

As aromatherapists, we recognize that the skin is a window to internal and external health. Skin pathologies cannot be effectively addressed without considering potential internal and emotional causes.

“Take a holistic approach to your skin’s health,” the Noodlemans advise. “Your skin responds not only to what you put in and onto your body, it also reflects your overall mental and physical health. Taking corrective and preventive measures that reduce sun-damage, increase exercise, promote healthy eating and decrease stress will help you look your best.”

Introduction to the Integumentary System

The skin is the most voluminous organ in the human body, comprising 15-16% of total adult body weight. It serves as the principal barrier between the internal body and the external environment. This deeply sensitive and resilient organ protects against biological, chemical, mechanical, and ultraviolet threats. As a significant contributor to systemic homeostasis, the skin regulates temperature, water balance, absorption and elimination, and vitamin D synthesis and mediates interactions between the immune, neurologic, and endocrine systems.

Understanding the Skin

The skin covers approximately eighteen square feet and weighs about twenty pounds. It is our largest vital organ, maintaining health and well-being in numerous ways. A single square inch of skin contains several million cells, around 650 sweat glands, about twenty feet of blood vessels, and thousands of sensory receptors.

• Unbroken, the skin’s primary function is to serve as a protective barrier against pathogens (bacteria/fungi) and excessive water loss while protecting underlying structures and organs.
• The skin regulates body temperature by constricting blood vessels in cold environments to preserve heat and producing sweat in warm conditions to cool through evaporation.
• As our largest sensory organ, the skin transmits neurological messages about touch, pressure, scent, pain, and temperature to the brain.
• The skin detoxifies by excreting wastes through sweat glands, synthesizes and stores vitamin D, and protects against UV damage by producing melanin. It also absorbs fat-soluble nutrients, including vitamins A, D, E, and K.
• The skin functions as part of the body’s immune system through its lymphatic network and specialized tissue constituents such as Langerhans cells. As a metabolic organ, the skin participates in fat metabolism, storage, and breakdown while helping regulate water and salt levels through perspiration.
• The skin maintains homeostasis through its protective function, temperature regulation, sensory perception, water balance, synthesis of vitamins and hormones, and absorption of essential nutrients.

The skin is a dynamic organ, continuously renewing as old cells shed and new cells develop. From infancy through adulthood and into old age, the skin adapts in size, shape, qualities, and functions according to changing demands.

A cross-section reveals three distinct layers: the epidermis (five layers), the dermis (two layers), and the subcutaneous layer. These layers work as an integrated system—a change in one layer inevitably affects the others.

ANATOMY AND PHYSIOLOGY OF THE SKIN

The skin consists of three main layers:

• The epidermis—the outermost layer
• The dermis—the middle layer
• The hypodermis—the innermost layer

The Epidermis

The epidermis consists of five layers where living cells transform into dead cells. These layers, from outermost to innermost, include:

• A. The stratum corneum. The outermost epidermal layer features tough cells called keratinocytes that produce keratin, a fibrous protein that strengthens and waterproofs the skin.
• B. The stratum lucidum. This thin “clear layer” varies in thickness, becoming more pronounced on palms and soles. It contains hardened, nonliving keratin-filled cells similar to the stratum corneum.
• C. The stratum granulosum. This “transitional layer” (1-4 cells thick) contains cells beginning to die and harden (keratinize), losing significant oil and water content.
• D. The stratum spinosum. This 5-8 cell layer shows progressively flattening cells that have lost some oil and water, becoming almost tile-like as they rise through the layer.
• E. The stratum germinativum. The deepest epidermal layer contains cube-shaped cells and is the only layer where cell reproduction (mitosis) occurs. Skin regeneration begins here, influenced by factors including age, diet, circulation, temperature extremes, light exposure, medications, and smoking habits. Each new cell’s average lifecycle spans 5-6 weeks.

Additional epidermal cells include melanocytes (producing the UV-protective pigment melanin), Langerhans cells(participating in immune response), and Merkel cells (mechanoreceptors for light touch sensation). The epidermis continuously renews itself and gives rise to cutaneous adnexa—skin appendages with roles in sensation, contractility, lubrication, and temperature regulation, including hair, hair follicles, sebaceous glands, sweat glands, and nails.

Note: Any skin treatment aimed at improvement requires at least 6-8 weeks before visible results appear.

The Dermis

Beneath the epidermis lies the dermis, which supports and nourishes the epidermis. The dermis comprises over 90% of the skin’s mass and consists of two layers: the papillary layer (outer) and the reticular layer (inner).

The papillary layer (approximately 1/5 of dermis thickness) contains loose connective tissue with capillaries, lymphatics, sensory neurons, and various fibers directly beneath the basement membrane. Its projections (papillae) form the base for fingerprint and toe print patterns.

The reticular layer, which bears most physical stress, contains dense collagen bundles and coarse elastin fibers, along with fibroblasts, mast cells, nerve fibers, lymph vessels, and epidermal appendages. This layer can stretch during pregnancy or weight gain, but tears when overstretched, creating stretch marks during healing.

The dermis contains:

• Connective tissue provides strength, resilience, and flexibility. The dermal connective tissue is made up of two primary fiber types: elastin, a protein that gives skin its elasticity (the ability to stretch and return to its original shape), and collagen, a complex protein that provides strength (comprising about 75% of fibrous material). These fibers are embedded in a gel-like substance primarily composed of mucopolysaccharides, particularly hyaluronic acid, which attracts and retains water to maintain skin moisture and flexibility.
• Blood and lymph vessels, including arterioles and capillaries, originate from subcutaneous arteries and veins. Vertical capillary loops supply nutrients to papillary structures and remove waste. Lymph vessels collect excess fluid that has diffused from capillaries, preventing swelling and removing waste.
• Hair follicles extend from the deep dermis to the skin surface. These tubular epithelial structures house growing hair. The erector pili muscle—the only skin muscle—attaches to each follicle, causing hair to stand erect in response to cold or emotion. Hair follicles provide entry points for essential oils to reach the dermal layer and bloodstream.
• Glands include sebaceous glands attached to hair follicles that produce sebum, an oily substance secreted onto the skin surface. Sebum lubricates hair and skin, prevents moisture loss, and has antibacterial properties. Some research suggests sebum may function primarily as a pheromone attracting the opposite sex. Sebaceous glands concentrate on the face, scalp, neck, upper back, and chest. The sudoriferous glands (sweat glands) help maintain body temperature through perspiration. When the hypothalamus detects elevated blood temperature, sympathetic nerves stimulate sweat glands. Evaporating perspiration cools the body. There are two types: apocrine (larger) and eccrine (smaller) glands.
• Sensory nerves make the skin our largest sense organ. Touch, critical for growth and development, communication, learning, comfort, and emotional bonding, was historically medicine’s primary therapeutic modality. Alternative treatments like massage and acupuncture are helping reintegrate touch therapy into medical practice.

The Hypodermis

The third layer below the dermis, the hypodermis, varies in thickness and consists of fatty tissue that provides body contours and smoothness. It cushions and protects vital organs, stores energy, and insulates effectively. The hypodermis functions as an endocrine organ, participates in immune response, and contains arterial networks branching into capillaries that extend into the dermis.

Skin Ecology: Layers of the Skin’s Barrier Function

As the principal interface between internal systems and the external environment, the skin maintains three interdependent protective layers collectively called the skin’s barrier: the dermal microbiome, the acid mantle, and the barrier function of the stratum corneum. Disruption of any of these systems has been linked to inflammatory skin conditions, including acne, rosacea, eczema, psoriasis, and atopic dermatitis. These layers work together to prevent infection and harmful substance entry, prevent water and nutrient loss, and maintain overall skin health.

The Dermal Microbiome

The skin microbiome comprises bacteria, fungi, and viruses. Like the gut microbiome, it significantly influences health and disease processes. Research shows diverse microbial populations colonize both the epidermis and dermis, modulating and informing immune system development. The skin creates an immense interface between the body and the environment, serving as a crucial convergence point between internal and external realms.

A key feature of the dermal microbiome is site-specific colonization—unique microbial communities inhabit distinct epidermal topographical niches determined by moisture content, anatomical location, and sebaceous gland prevalence. Researchers note that moist and dry skin sites are “as ecologically dissimilar as rain forests are to deserts.” Areas rich in sebaceous glands (back, face, chest) feature primarily Cutibacterium (formerly Propionibacterium) bacteria and Malassezia yeasts. “Dry” sites (buttocks, arms, legs) show the highest microbial diversity, predominantly Cutibacterium acnes, and Staphylococcus species. These microbes, along with Corynebacterium, represent the main commensal organisms found on skin.

Beyond body site differences, microbial signatures vary with local microenvironment changes between individuals and age groups and with health status, behaviors, and environmental exposures. Most skin microbiota are harmless or beneficial and essential for host defense. Despite popular belief that certain microbes are inherently dangerous, pathogenicity typically occurs only during dysbiosis—when microbial ecosystem balance is disturbed, or diversity diminishes—or when opportunistic bacteria breach the skin surface.

Skin-dwelling microbes play key roles in host defense and tissue repair. Disruptions to the stratum corneum microbiome from antibiotic use, hygiene practices, lifestyle factors (especially stress), and even gut dysbiosis can impair skin barrier function and increase transepidermal water loss (TEWL). Dysbiosis and reduced dermal biodiversity have been linked to numerous skin conditions, including atopic eczema, atopic dermatitis, acne, rosacea, psoriasis, impaired wound healing, inflammation, and skin cancer.

Sebaceous Glands, Sebum, and the Dermal Microbiome

Sebaceous glands, microscopic exocrine glands producing sebum, critically regulate skin homeostasis. They support barrier functions, promote skin integrity, mediate inflammation, deliver antioxidants, and manage microbial populations. They also participate in cutaneous endocrine and immune systems and function as stem cell reservoirs. Sebaceous glands distribute throughout the body except for the palms of the hands and soles of the feet, with the highest concentration on the scalp, face, neck, upper back, and chest.

Sebum combines fats (triglycerides, wax esters, squalene, cholesterol) and cellular debris discharged through the sebaceous duct connecting the gland to the hair follicle. It creates a protective film, maintaining pliability and regulating fluid exchange. Sebaceous glands produce distinctive lipids, including sapienic acid (unique to sebum), squalene, wax esters, triglycerides, and smaller amounts of cholesterol, cholesterol esters, and diglycerides.

Sebaceous glands promote healthy skin homeostasis by maintaining a balanced microbiome.
Sebum composition significantly influences cutaneous microbiota, restricting unwanted microbes while fostering beneficial populations. Sapienic acid (C16:1 n-10) demonstrates particularly notable antibacterial properties.

Sebaceous gland dysfunction contributes to conditions like acne and dry skin. Overproduction or altered chemical composition of sebum can cause acne, while insufficient production may lead to xerosis (abnormal skin or mucous membrane dryness), accelerated skin aging, and atopic dermatitis.

The Skin’s Acid Mantle

The epidermis is covered with a thin layer of natural lipids, and perspiration called the acid mantle. These lipids derive from sebum and the stratum corneum, while sweat glands produce perspiration. The acid mantle primarily protects against microbial infections and supports barrier function and stratum corneum integrity. It maintains an average pH of 4-6, varying with gender, age, and anatomical location.

Other influencing factors include sebum, skin moisture, sweat, genetics, detergents, topical antibacterials, occlusive dressings, and skin irritants. When the acid mantle loses acidity, the skin becomes more vulnerable to damage, infection, irritation, and sensitivity. The acid mantle represents a vital defense system containing elements that maintain crucial moisture levels, and carrier oils help support this valuable system.

About pH

The abbreviation pH stands for “power of hydrogen” or “potential of hydrogen” and measures a substance’s acidity or alkalinity. pH values range from 1 (most acidic) to 14 (most alkaline).

Water has a neutral pH of 7. Skin pH is slightly acidic, ranging from 4 to 6. Therefore, the skin benefits from neutral to slightly acidic products that support overall skin health.

The Skin’s Barrier Function

The skin’s barrier function is essential for human health. Under normal conditions, the stratum corneum maintains optimal skin hydration, supports innate antioxidant systems, produces microbe-regulating peptides, activates immune responses, and defends against external threats, including ultraviolet radiation, environmental toxins, allergens, and pathogens. According to Belkaid and Tamoutounour, “the skin is therefore charged with the formidable task of protecting the host from microbial invasion while maintaining a peaceful coexistence with its resident microbiota.”

The stratum corneum prevents the absorption of harmful substances and pathogen entry while restricting excessive water loss by providing a physical barrier between our bodies and the environment. It consists of corneocytes (terminally differentiated keratinocytes) encased in an extracellular protein and lipid matrix. This layer employs a “brick and mortar” design where cells (corneocytes) act as “bricks” while intercellular lipids serve as “mortar,” binding moisture between them.

Keratinocyte differentiation closely connects with extracellular matrix development. Lipids produced during epidermal differentiation originate from lamellar bodies (small secretory cells within keratinocytes) expelled from keratinocytes in the stratum granulosum. As differentiation concludes, lamellar granules discharge lipids and hydrolytic enzymes into intercellular spaces. These enzymes act on nearby phospholipids, producing the principal stratum corneum lipids.

This extracellular lipid matrix provides mechanical barrier functions, protecting the underlying epidermis and preventing both water loss (outward) and invasion by external particles and pathogens (inward). This bi-directional protection represents the epidermis’s principal role, specifically that of the stratum corneum.

Lipids of the Stratum Corneum

The principal stratum corneum lipids include ceramides (approximately 50%), cholesterol (27%) and its esters (10%), and fatty acids (10-15%). This lipid “mortar” prevents water loss through the stratum corneum.

Ceramides, a sphingolipid class, trap water molecules in their hydrophilic regions. These lipids form stacked bilayers with hydrophobic “heads” facing outward and hydrophilic “tails” pointing toward the opposing layer, surrounding corneocytes. This bilayer blocks water passage, preventing the loss of both water and natural moisturizing factor (NMF) through the skin.

Cholesterol, the most prevalent stratum corneum lipid, lubricates multiple layers of dry, dead cells, enhancing stratum corneum flexibility. Squalene, secreted onto the skin by sebaceous glands, serves as cholesterol’s precursor.

Fatty acids in the skin provide lubrication, support barrier function, prevent moisture loss, maintain acidic pH, and contribute to innate immunity through antimicrobial activity. Skin fatty acids include palmitic acid (C16:0), palmitoleic acid (C16:1 n-7), myristic acid (C14:0), stearic acid (C18:0), and linoleic acid (C18:2 n-6)—the most abundant polyunsaturated fatty acid (PUFA) in the epidermis.

Transepidermal Water Loss (TEWL) and the Natural Moisturizing Factor (NMF)

The stratum corneum regulates water levels in underlying skin and controls natural moisture flow from deeper layers before eventual evaporation from the skin surface. This flow is called transepidermal water loss (TEWL), and moisture homeostasis is crucial for maintaining barrier function and overall skin health.

Stratum corneum lipids and the natural moisturizing factor (NMF) maintain skin hydration and reduce TEWL. The NMF, found within corneocytes, consists of water-soluble compounds, including amino acids (approximately 50%), urea, lactic acid, inorganic salts, sugars, and electrolytes. These compounds, derived from filaggrin protein breakdown, keep skin moist and pliable by attracting and retaining water, supporting desquamation (corneocyte shedding), and maintaining stratum corneum barrier function.

NMF components act as humectants, attracting and absorbing atmospheric water and drawing moisture into corneocytes. Low NMF levels may contribute to skin aging, disorders, ichthyosis, and general xerosis.

The Role of Fatty Acids and the Skin

Lipids form essential components of all cellular membranes and influence permeability. Triglycerides, phospholipids, sphingolipids (glycosylceramides), and ceramides all contribute to epidermal barrier function. Fatty acids, which constitute these cellular lipids, maintain stratum corneum structure and function, where they provide moisture and insulation barriers. They enhance barrier function, offer anti-inflammatory benefits, serve as natural penetration enhancers, and support healthy skin activities.

Essential fatty acids (EFAs) are particularly important for normal stratum corneum structure and function. Linoleic acid (LA), an essential fatty acid component of ceramides, plays a crucial role in intercellular lipid complex formation. EFA deficiency alters barrier function, disrupts epidermic homeostasis, and can cause excessive TEWL, dryness, scaliness, redness, dermatitis, and other inflammatory signs.

Additional factors affecting stratum corneum lipids include temperature extremes (sunburn, windburn, frostbite), low humidity, winter heating, age, genetics, seasonal changes, and diet. Solvents, detergents, irritating chemicals, and even excessive water and soap use can break down protective lipid layers and increase TEWL by compromising natural water-holding capacity. Lipid deficiencies may result in dehydrated skin or xerosis. Even acute psychological stress can negatively impact barrier function.

Moisturizers and Skin Barrier Repair

Maintaining a healthy skin barrier is essential, particularly for individuals with conditions exacerbated by dryness, such as psoriasis, atopic dermatitis, and photodamage. These disorders involve fundamental barrier dysfunction, increasing vulnerability to environmental factors causing dryness and irritation.

Daily skin maintenance is crucial for both adults and children, even without such conditions.

Moisturizers include emollients, humectants, and occlusives. Applied topically, they improve, maintain, and support barrier function while enhancing hydration by preventing or reducing TEWL.

• Emollients (from Latin “to soften”) smooth the skin surface, prevent TEWL, reduce inflammation, and support the lipid matrix. Emollient products include carrier oils, creams, lotions, ointments, butters, and balms.
• Humectants (such as honey and glycerin) attract water to the skin.
• Occlusive substances (waxes, lecithin) create a hydrophobic layer on the skin surface, preventing TEWL.

Topical carrier oils and products containing them effectively deliver fatty acids to the skin and may help prevent and treat skin conditions. Generally, topical fatty acids support the structure and barrier function of the stratum corneum.

Both the topical application and ingestion of linoleic acid-rich oils can reverse symptoms of EFA deficiency in animals and humans. Topical carrier oils, particularly those rich in essential fatty acids, can significantly benefit skin barrier restoration, wound healing, wrinkle prevention, and the treatment of inflammatory conditions, including eczema, dermatitis, and psoriasis.

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Watch: Meet the Skin

 

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The Oral Route

This method of application will be in Module 7: Introduction to Aromatic Medicine. This module will explore the dermal and olfactory/respiratory routes.

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The Core Pathways into the Body for Essential Oils include:

1. The Skin
2. Olfaction/Inhalation
   and
3. Internal (This course will cover the basics of oral use only. Other methods are covered in our Aromatic Medicine Certification course.

In this module, we will be covering the Skin and Olfaction. In the Intro to Aromatic Medicine, we will be covering Oral Use.

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