Foundations of Aromatherapy

Sweet orange

Citrus sinensis (L.) Osbeck syn. Citrus aurantium var. sinensis L.

Watch: About Sweet Orange with Jade Shutes

BOTANICAL INFORMATION

Common name: Sweet orange
Scientific name: Citrus sinensis (L.) Osbeck
Synonym: Citrus aurantium var. sinensis L.
Botanical family: Rutaceae
Conservation status: Not defined

Description: Citrus x sinensis is an evergreen flowering tree in the Rutaceae family. Sweet orange typically grows 9-10 meters tall, and features large spines on the branches. The leaves are alternate, with narrowly-winged petioles, elliptical to oval in shape, toothed, and strongly redolent of citrus. Flowers are axillary, borne singly or in whorls. Each flower is composed of five white petals and 20-25 yellow stamens. Fruit is globose to oval, and ripens to orange or yellow. The fruit is divided into the pericarp, or peel, and endocarp, the pulpy inner portion composed of juice sac glands. The skin of the fruit is made up of a waxy epidermis studded with numerous aromatic oil glands.

C. sinensis is native to Asia, and naturalized throughout the Pacific and warm regions of the world. Sweet orange is the most widely cultivated citrus in the world, and accounts for approximately 70% of global annual citrus production.

Ethnobotany: Sweet orange is valued throughout the world as a rich source of antioxidant vitamin C. C. sinensis has been used in traditional systems of medicine to ease constipation, cramps, colic, diarrhea, bronchitis, tuberculosis, cough, cold, obesity, menstrual ailments, angina, hypertension, anxiety, depression, and stress.¹

EXTRACTION INFORMATION

Country of origin: Israel, USA, Spain, Italy
Part of plant used: Peel/zest of fruit
Extraction method: Expression or Distillation
Essential oil yield: 0.2-3.5%
Color of oil: Clear to light yellow

AROMATIC CHEMISTRY

Cold pressed essential oil

Thirteen components make up 97.9% of the whole cold pressed Citrus sinensis essential oil. The core components include: d-limonene (90.5-96.7%) and myrcene (1.42-2.5%). All other components were present at less then 1%.²

Distilled essential oil

Forty-seven components make up 97.15% of the distilled essential oil. Core components include: limonene (80.14-89.23%), myrcene (1.77-2.73%), n-octanal (1.08-1.28%), (z)-b-ocimene (2.9%), terpinolene (2.26%), linalool (1.75-2.98%). All other components were present at less then 1%.^3,4

SAFETY INFORMATION

• Dermal alert: Sweet orange has a shelf life of 1 – 2 years when stored correctly. Over time, sweet orange, specifically its main component, limonene, oxidizes. When this happens, there is an increase in the chance of dermal sensitization.⁵ Oxidized citrus essential oils, such as bergamot, should not be used in body care products for application to the skin. The essential oil can, however, be used for cleaning products.
• Average shelf life for monoterpene-rich essential oils, when stored correctly is 1-3 years.
• GRAS status.
• Expressed sweet orange is not phototoxic. **Blood orange (Citrus sinensis L. cv. Sanguinella and Citrus sinensis L. cv. Moro), is a cultivar of sweet orange and its expressed essential oil is also not phototoxic.⁶

THERAPEUTIC ACTIONS

Airborne antiseptic, anti-inflammatory⁷, antimicrobial⁸, antiviral, anxiolytic, carminative, digestive tonic, diuretic, nervine, sedative

SYSTEM AFFINITIES

Nervous, Digestive, Psyche/Emotion

BLENDING INFORMATION

Aroma description: Refreshing, citrusy, orange
Blending factor: 7 – 8
Notes: Top
Blends well with: Neroli, Other citrus essential oils, lavender, jatamansi/nard, sweet marjoram, frankincense species, cedarwood, patchouli, elemi, clary sage, Roman chamomile, coriander seed
Substitutions: Mandarin, lemon, grapefruit, bergamot

CORE INDICATIONS

• General: air purifier (D+++)
• Digestive system: indigestion, nervous stomach, dyspepsia (O+++, I+++, D++, C+++)
• Nervous system: insomnia, anxiety, depression, agitation, restlessness (O+++, I+++, D+++, C+++)
• Psyche/emotion: stress, irritability, depression (O+++, I+++, D+++, C+++)
  ________________

Traditional Chinese Medicine (TCM): orange unblocks and circulates stagnant Qi-energy, mainly when it accumulates in the liver, stomach, and intestines.

__________________

RESEARCH

Human Studies

• Citrus sinensis (sweet orange) essential oil demonstrated anxiolytic activity.¹

• In a small trial of twenty-four individuals (12 men, 12 women), the inhaled aroma of Sweet orange (Citrus sinensis) essential oil increased physiological arousal (sympathetic tone) and at the behavioral level, individuals who inhaled sweet orange rated themselves more alert then the control group. The researchers believe that this furnishes scientific proof that the inhalation of sweet orange may be of benefit for the relief of mild depression and stress in humans. Note: The group was divided into two with one group inhaling sweet orange and the other group inhaling pure water vapor only.¹⁰

• Sweet orange (Citrus sinensis) essential oil exhibits ‘harmonizing’ activity when applied to the skin.
A 2007 study published in the International Journal of Essential Oil Therapeutics used a placebo controlled study to examine the effects of transdermal absorption of sweet orange essential oil on autonomic nervous system and on mental and emotional states. The study involved thirty-nine volunteers randomly assigned to either the control group or the sweet orange group. The control group applied 1ml of sweet almond oil while the sweet orange group applied 1ml of a 20% (w/w) solution of sweet orange oil in sweet almond oil to the skin of the lower abdomen which was self massaged into the skin for 5 minutes. The area was then covered with plastic film to prevent evaporation of the oil. Autonomic parameters including breathing rate, pulse rate, skin temperature, and systolic and diastolic blood pressure were monitored continuously. The sweet orange group experienced a reduction in pulse rate and breathing rate. Subjects in the sweet orange group also experienced feeling more cheerful and vigorous. The researchers summarized that dermal application of sweet orange essential oil resulted in ‘harmonization’, which they defined as a reduced level of arousal of the autonomic nervous system (reduction of pulse and breathing rate) yet increased cheerfulness and vigor on the behavioral level as reported by individuals in the sweet orange group. The researchers concluded that the dermal application of sweet orange essential oil may be of benefit in the relief of depression and stress in humans.¹¹

Animal Studies

• Citrus sinensis (sweet orange) essential oil demonstrated anxiolytic activity.¹²

Eucalyptus, Blue Gum

Eucalyptus globulus Labill.

Watch Presentation on Eucalyptus with Jade Shutes

BOTANICAL INFORMATION

Common names: Blue gum, blue mallee, eucalyptus
Scientific name: Eucalyptus globulus Labill.
Botanical family: Myrtaceae
Conservation status: Least concern¹

Description: Eucalyptus globulus also known as the southern blue gum, is a large evergreen tree in the Myrtaceae family native to Tasmania. This tree varies in size from 20 meters to 70-80 meters tall. The lower bark is rough and greyish/brownish, the upper bark is smooth, pale with a bluish or yellowish tinge, and peels into long strips. The tree has a single trunk with many branches. In harsh, exposed sites, E. globulus grows as a many-stemmed shrub.

Southern blue gum is found in Tasmania, southern Victoria, and is invasive in California and Hawaii. The tree thrives in regions with a Mediterranean climate marked by warm dry summers and cool wet winters. In California, the Tasmanian blue gum prefers disturbed areas, hillsides, and coasts below altitudes of 300 meters.

Ethnobotany: Tasmanian blue gum is commonly planted as a hedge or screen, and as an ornamental in parks and gardens. The wood is used in paper manufacture, and plantation-grown trees are used for pulpwood. The essential oil, derived from the leaves and shoots, is used medicinally, in perfumery, and in insect repellents.²

E. globulus has been valued in traditional medicine for its antiseptic and antimalarial properties. The oil was used as a stimulant and antiseptic gargle, and an emulsion of the oil and powdered gum-arabic in water has been taken internally for pulmonary tuberculosis, bronchitis, and other infectious diseases of the lungs.³

EXTRACTION INFORMATION

Country of origin: Australia, South Africa
Part of plant used: Leaves and mature branches
Extraction method: Distillation
Essential oil yield: 1-3% w/w
Color of oil: Pale yellow to clear

AROMATIC CHEMISTRY

Fourteen+ components make up 99.77% of the essential oil of Eucalyptus globulus. The core component is: 1,8 cineole (72.71-85.82%). Other components include:

Monoterpenes: a-pinene (4.15-9.22), b-pinene (0.4-1.1%), camphene (t-), myrcene (1.52%), a-phellandrene (0.55%), p-cymene (t-2.93%), limonene (0.85-8.16%), y-terpinene (1.16%), a-terpinene (0.11%), sabinene (0.25%), terpinolene (0.19%)
Monoterpenols: linalool (0.24-0.43%), pinocarveol (0.44%), terpinen-4-ol (0.34-0.49%), α-terpineol (0.14-2.54%)
Sesquiterpenols: globulol (2.77%), epiglobulol (0.44%), b-eudesmol (0.38%)
Esters: a-terpineol acetate (3.1%), geranyl acetate (0.71%)
Ethers (oxide): 1,8 cineole (72.71-85.82%)^4,5,6

SAFETY INFORMATION

• Caution for children: Avoid application of 1,8 cineole-rich essential oils to the face or near the nose of infants and children under age of 5. Do not instill 1,8 cineole-rich essential oils into the nose of infants or children. Use low dilutions (less then 1%).
• Internal contraindication: Essential oils rich in 1,8 cineole should not be used with infants or young children via the internal route (oral, rectal suppositories, etc.)

THERAPEUTIC ACTIONS

SYSTEM AFFINITIES

Respiratory

BLENDING INFORMATION

Aroma description: Strong, camphor like, balsamic, fresh
Blending factor: 1 – 5
Note: Top note
Blends well with: Other eucalyptus oils, Laurel, Rosemary ct. cineole or camphor, Lavandula latifolia, Lavender, Cardamom, Peppermint, Green myrtle, Rosalina, Ravintsara, Pinus pinaster, Pinus sylvestris, Lemon, Tea tree

Substitutions: Rosemary ct. cineole, Eucalyptus radiata, Eucalyptus polybractea, Laurel, Eucalyptus dives, Niaouli, Myrtle ct. cineole, Ravintsara ct. cineole

CORE INDICATIONS

• Circulatory system: poor circulation (C+++)
• Digestive system: Diarrhea (caused by viral infection), intestinal parasites, candidiasis/thrush¹⁵ (O+++)
• Musculoskeletal system: muscular aches and pains, arthritis, rheumatism, plantar fasciitis, sprains (C+++)
• Respiratory system: chronic bronchitis, acute bronchitis, sinusitis, rhinitis, rhino-pharyngitis, asthma, antiseptic qualities good for sore throat and infections, laryngitis, clears the head especially when used with rosemary and peppermint, nasal congestion, coughs, cold, flu, pertussis, thins bronchial sputum (O+++, SI+++, RS+, D+++, I+++)
• Skin: herpes simplex¹⁶, shingles, chickenpox, measles, acne, ulcers, wounds, mycotic infections, boils, burns, cuts (C+++)
• Psyche/emotion: uplifting, refreshing, can have a “cooling” emotional effect, clears and stimulates the mind, aids concentration, good for exhaustion, balancing when there is an energy imbalance, purifying and cleansing to negative energies, especially after an argument (I+++, D+++, C+++)
  __________________
• Ayurveda: Useful for Kapha excess conditions presenting as mucus or lethargy. Eucalyptus globulus has a pungent rasa and vipaka. In moderate does it is cooling, but it is heating in large quantity. Pacifies vata and kapha, it primarily acts on the lungs and sinuses (decongesting and bronchodilator). Eucalyptus has a cooling effect on the surface of the skin, but is heating on the mucus lining.¹⁷
• Traditional Chinese Medicine (TCM): Eucalyptus is unparalleled in its ability to clear Lung-Phlegm for TCM work and as a general tonic to Lung-Qi; is suited to the individual who feels emotionally “hemmed-in” or constricted by their surroundings and can help to provide “room to breathe”.
  _________________

RESEARCH

• Eucalyptus (Eucalyptus globulus) essential oil exhibited strong bactericidal and anti-inflammatory activities. The essential oil is also an expectorant and stimulates bronchial secretions.¹⁸
• Eucalyptus (Eucalyptus globulus) essential oil is thought to increase the motility of the cilia, thus explaining the expectorant effect of this oil.¹⁹
• Eucalyptus (Eucalyptus globulus) essential oil exhibits acetylcholinesterase (AChE) inhibitory activities.²⁰ Acetylcholinesterase (AChE) is the principal enzyme involved in the hydrolysis of acetylcholine (ACh).

Human Studies

• Inhalation of Eucalyptus (Eucalyptus globulus) essential oil reduces pain in patients after total knee replacement surgery.
  Eucalyptus oil was dissolved at a concentration of 3% (v/v) in almond oil. In experimental group, eucalyptus oil (dissolved in almond oil) was placed onto a 4 × 2-inch gauze pad, which was positioned between the nose and philtrum (a vertical groove in the middle area of the upper lip) and inhaled for 30 minutes on 3 consecutive days, beginning on the third day after surgery for total knee replacement (TKR). Individuals in the eucalyptus group experienced a reduction in subjective pain and blood pressure after surgery. These findings suggest that the inhalation of eucalyptus oil might be a valuable nursing intervention for pain relief after TKR.²¹
• **Note: The majority of human studies have been performed using isolated 1,8 cineole. This will be covered in the lesson on oxides.

Animal Studies

• Eucalyptus (Eucalyptus globulus) leaves taken internally showed a considerable inhibitory effect on the growth of Candida albicans in both normal and diabetic rats.²²
• Eucalyptus (Eucalyptus globulus) essential oil demonstrated analgesic and anti-inflammatory activity.²³
• Eucalyptus (Eucalyptus globulus) essential oil exhibits strong antibacterial activity, and in combination with tea tree and grapefruit essential oils was successfully used treat the malodor of necrotic ulcers in 25 patients.²⁴
• Eucalyptus (Eucalyptus globulus) essential oil exhibits ability to control sebum production by reducing size of sebaceous glands in rats and therefore may be useful in the treatment of acne.²⁵

In Vitro Studies

• Eucalyptus globulus essential oil exhibits antibacterial activity against isolated from respiratory infections such as: Staphylococcus aureus, Streptococcus pyogenes, S. pneumoniae and Haemophilus influenzae, H. parainfluenzae, Stenotrophomonas maltophilia.²⁶
• Eucalyptus globulus essential oil is able to stimulate innate cell-mediated immune response. Researchers summarized that eucalyptus has the potential for being an immune-regulatory agent with potential applications for immuno-suppressive pathologies as well as infectious diseases.²⁷
• Eucalyptus globulus essential oil exhibited anti-candidal activity and inhibited filamentation of these fungi.²⁸
• Eucalyptus globulus essential oil exhibits antiviral activity against the herpes simplex virus.²⁹

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.

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.

Watch Videos:

Olfaction: Structure and Function

ANATOMY AND PHYSIOLOGY OF OLFACTION

Smell begins with the breath, and breathing is the most vital of human bodily functions and the most necessary for survival. As human beings, we could survive days without food and water and yet only minutes without air. Breathing occurs in two wondrous phases: inhalation and exhalation. Throughout our lives, breaths come in pairs, with the exception of birth, when we inhale for the first time, and death when we exhale for the last time. As we go about our day, we breathe approximately 23,000 times and move approximately 440 cubic feet of air.

We live in a world that provides a constant abundance of aromas swirling in the air around us. With every breath, we take in a dynamic landscape of aromas that can be consciously or unconsciously registered, and yet they are there, surrounding us, beckoning for recognition.

The Nose

The nose includes an external portion that juts out from the face, and an internal portion called the nasal cavity, which is responsible for the passage of air. The nose is divided into two by the nasal septum, which is made up of septal cartilage and the ethmoid and vomer bones.

Inside each nasal cavity are two parts: the olfactory part and the respiratory part.

The olfactory part of the nasal cavity is made up of the upper (superior) portion and a portion of the central section of the nasal cavity, while the remaining tissue closer to the projection of the nose and a portion of the central section is the respiratory part.

Sniffing increases the airflow through to the upper sinuses, hence increasing our perception of an aroma.

The respiratory part of the nasal cavity is lined with columnar and ciliated epithelium, while the cells in the olfactory portion are made of columnar yet non-ciliated epithelium. The entire inside of the nasal cavity is generously supplied with mucus-secreting goblet cells.

The main functions of the nasal cavity include:

• Warms, moistens and cleanses the air we breathe in through the nose.
• Nasal hairs filter the air of small particles.
• Contains the olfactory epithelium, located in the upper portion of the nasal cavity.
• Plays a role in voice phonetics and acts as a resonating chamber.

Olfactory Epithelium

Piet Vroon, the author of ‘Smell: The Secret Seducer,’ considers olfactory epithelium to be the actual organ of smell. Let us explore this interesting tissue, which resides in the upper portions of our nasal cavities.

An odor, smell, or aroma is created by minute gaseous-like particles released by various objects or substances. When we smell lavender, for instance, its purple, sweet aroma enters our nasal cavity. As the aromatic air-born molecules travel up through the nasal cavity, some molecules are absorbed by the olfactory epithelium, while the remainder is inhaled via the respiratory tract into the lungs.

Olfactory epithelium is a specialized epithelial tissue inside the nasal cavity that is involved in smell. In humans, it measures about 2 cm by 5 cm long (about 1 inch wide by 2 inches) and lies on the roof of the nasal cavity about 3 inches (about 7 cm) above and behind the nostrils. The olfactory epithelium in each nostril contains over 3-5 million olfactory receptor cells (ORC). Total receptor cells in the nasal cavity: 6-10 million.

These olfactory receptor cells are bipolar neurons that function as chemoreceptors (sensory receptors that create a chemical signal into a nerve impulse). Bipolar neurons are neurons that have two branching processes: a dendrite and a neurite.

The dendrites of olfactory sensory neurons project directly onto the surface of the mucus membranes, with each dendrite ending in several fine, hair-like projections known as cilia.

These cilia extend beyond the epithelium surface into the mucosa and are considered to be naked neurons, which means they are in direct contact with the outside world. Olfactory receptor cells are found in these tiny hairs or cilia. The cilia, immersed in a fluid mucus layer, are the site of interaction between odors and the receptor neuron (olfactory transduction).

The neurites, on the other hand, run inward and upward and are believed to serve as a connection to the olfactory nerve. Thickness and viscosity of the olfactory epithelium is variable in each person and can be affected by hormones, diet, and health.

Other cells contained within the olfactory epithelium include support cells and basal cells.

• Sustentacular Cells: The sustentacular cells play a variety of crucial roles to keep the olfactory sensory neurons (OSNs) functioning at their best. Sustentacular cells are like the ultimate support staff. They provide structural scaffolding to keep the OSNs neatly organized, supply them with essential nutrients and energy, and maintain the optimal balance of fluids and ions in their environment. They even act as the cleanup crew, gobbling up debris, damaged cells, and potential microbial invaders to keep the epithelium spick and span.
• Basal cells are found on the underside of the epithelium. Olfactory basal cells are capable of neurogenesis, which means they are capable of creating new nerve tissue to replace the old. And this is exactly what happens with the sense of smell. Because olfactory cilia are exposed directly to the air and everything that the air contains, their life is short.

Olfactory epithelium regenerates every 30-60 days. This incredible ability of the olfactory tissue to reproduce nerve tissue illustrates its importance to human survival and the experience of living.

Interesting Fact: Pregnancy and Olfactory Neurogenesis

Early during pregnancy, there is a huge burst in the production of new olfactory neurons. They are fully online just around the time of birth, and the scientist who discovered this speculated that these new olfactory neurons are tagged for the task of imprinting forever on the smell of your offspring (a critical event for mothers of most mammals). The new olfactory neurons that show up in early pregnancy may have something to do with the famed nausea of pregnancy, food aversions, and olfactory sensitivities.

Many factors play a role in the rate and magnitude at which an aroma is absorbed into the olfactory epithelium. These factors include:

1. The solubility of the aroma itself: lipophilic or fatty substances will dissolve very easily in the olfactory epithelium
2. Molecular weight of the odorant: The heavier the molecular weight, the more difficulty the molecule will have moving in the air current, and hence absorption will be reduced.
3. Thickness of mucus layer: A thickened mucus layer slows down the speed of reaction to an odorant and, at times, can create partial anosmia. (E.g., such as during the common cold) It is known that individuals who smoke have a thicker mucus layer in their olfactory epithelium, making their ability to smell just slightly impaired, I say slightly, because a thickened mucus layer also enhances smell. Let me explain. When there is a thickened mucus layer, there are a larger number of olfactory cilia; as a result, an odorant is able to make a number of attachments, thus increasing its substance concentration and impact.

Cracking the Code of Smell: The Nobel-Winning Discovery

In 2004, two brilliant scientists, Dr. Linda Buck and Dr. Richard Axel, were awarded the Nobel Prize in Physiology or Medicine for their groundbreaking work on the sense of smell. Their research aimed to answer two big questions: How can we smell so many different odors, and how does our brain make sense of all this information?

Buck and Axel had a hunch that the key lay in a wide variety of odor receptors. And they were right! Through their work, they identified around 350 different types of these smell-detecting molecules. But the real magic happens when these receptors team up.

Imagine odor receptors as letters of the alphabet. Just as you can create countless words with only 26 letters, different combinations of receptors can recognize an endless array of scents. Each odor molecule fits into several receptors, and it’s this unique pattern of activation that lets us identify a particular aroma.

But the story doesn’t end there. Buck and Axel also discovered that as smell information travels from the nose to different parts of the brain, it gets organized in new ways at each step. In the olfactory bulb and cortex, the smell “code” is deciphered, and the various components are brought back together to create a cohesive scent perception.

From there, the information journeys to brain regions, allowing us to not only identify the scent but also associate it with memories and emotions. So, the next time you catch a whiff of your favorite food or a nostalgic aroma, remember the incredible work of Buck and Axel and the complex interplay of receptors and brain regions that makes it all possible!

To read more about their Nobel prize, visit: http://www.nobelprize.org/nobel_prizes/medicine/laureates/2004/press.html

This image was obtained from:
http://www.nobelprize.org/nobel_prizes/medicine/laureates/2004/press.html

Pathway of an Aroma

Once the olfactory epithelium receives an odorant or aroma, a nerve impulse is initiated into the olfactory bulb. The olfactory bulb sits on top of the cribriform plate of the ethmoid bone and is continuous with the olfactory tract. The olfactory nerves are connected at the bottom of the bulb. The olfactory bulb serves as the first site of odor recognition before it is passed on.

The nerve impulse is passed from the olfactory bulb along the olfactory tract. The olfactory tract is a band of white matter that sends odor-related nerve impulses to the limbic system, beginning with the amygdala. Heavy innervation of the amygdala by primary olfactory structures provides a powerful mechanism for the rich experiences that can stem from olfactory sensation. The role of the amygdala in emotion, memory, and autonomic control directly ties olfaction to these primordial functions and adds complexity to the odor perceptual experience.

The temporal and frontal lobes then interpret and perceive the odor. Thus, olfactory nerve projection encompasses the entire limbic region and associated pathways. Impulses that reach the limbic system activate smell-related emotions and behaviors.

Now, let us explore the limbic system!

Watch: About Undiluted Application

UNDILUTED APPLICATION

Undiluted or “neat” application is the use of essential oils applied directly to the skin without a carrier or base oil. In general, undiluted application is only applied in a specific localized area, most commonly for acute conditions, treatment work, or for reflex/acupressure work.

The undiluted application of essential oils is a highly controversial topic within the aromatherapy industry. Leading authors and educators all differ in their opinions and usually can be found in one of two camps—those who believe the undiluted application of essential oils is extremely beneficial and indeed called upon under specific circumstances and those who believe that essential oils should absolutely not be placed on the skin undiluted and that doing so is not only extremely hazardous but also unprofessional. Like internal use, the pendulum swings from one extreme to the other without providing an appropriate context of when and why this is SOMETIMES appropriate.

Many aromatherapy practitioners believe that only the following essential oils should be used undiluted: Lavandula angustifolia, Melaleuca alternifolia, Helichrysum italicum, and Chamaemelum nobile. Given the list provided, it would make sense that many other essential oils with similar chemical makeup should also be considered safe for undiluted application when done under proper conditions by a trained and knowledgeable therapist or individual.

Undiluted application may be appropriate for the following acute conditions:

• Acne (spot treatment)
• Cold sore (sandalwood or geranium works great!)
• Minor burn (although I have actually found lavender or cape chamomile in aloe vera gel works much better!)
• Minor skin trauma or infection
• Insect bites
• Migraines (acute)
• Bruises (acute – when it first happens, applying Helichrysum italicum and/or Matricaria recutita can be incredibly beneficial!)
• Musculoskeletal trauma (e.g. whip lash: think Helichyrsum italicum and/or Matricaria recutita)
• Reflex or acupressure work
• Ear infections (just behind ear and on reflex points associated to the ears on the feet)

Specific essential oils that tend to be safe to apply undiluted include tea tree (Melaleuca alternifolia) **Be sure it has not oxidized!, lavender (Lavandula angustifolia), helichrysum (Helichrysum italicum), Roman chamomile (Chamaemelum nobile), rose (Rosa damascena), and sandalwood (Santalum album or Santalum spicatum), Cypress (Cupressus sempervirens), Eucalyptus (Eucalyptus radiata or globulus), Bay Laurel (Laurus nobilis), etc.  It is important to only use a small amount (1 to 2 drops) of essential oil. Other essential oils may be used for reflex or acupressure points; however, care should be taken in selecting essential oils, and essential oils that can be irritating, sensitizing, or are rich in aldehydes or phenols should be avoided altogether for undiluted application due to dermal irritation or sensitization which may occur.

Safety note: Some individuals within the aromatherapy profession are quick to point out that it would seem to be more prudent to err on the side of caution due to the litigious society we live in. From the author’s point of view, we have included undiluted application because it has some valid uses. However, it is up to the individual practitioner to decide whether this method of application is right for them and/or their client. (from our book, Aromatherapy for Bodyworkers) Please note, too, that we are not advocating the wide spread usage of undiluted essential oils but rather simply to find a middle ground. It is not ‘Never apply undiluted’ NOR is it to apply undiluted essential oils with abandon. One must always have a purpose, a reason for doing so that is based upon the safety of the individual essential oils being utilized.

My own observations over the years have been:

• Not all individuals can have undiluted essential oils applied to their skin. Fair-skinned or red-headed individuals tend to be more sensitive, but it could be anyone. Best to err on the side of caution for sure. When I lived in Seattle (even today during the winter months), I often applied 3-4 drops of Eucalyptus globulus to my neck each morning. I never had a reaction. Then, one day, I did this on a friend, and he quickly got two red lines of irritation on his neck where I had placed the oil. He was fair-skinned. Lesson learned. Although no harm was done, I am sure clients would not appreciate this.

• Not all irritation is of the same strength. In my advanced program, I have each of the students apply undiluted thyme ct. thymol onto the inside of their arm. Over the years, I have noticed the following:

1. 1. some individuals react very quickly with inflammation directly in the area where the oil was applied
   2. some individuals do not react at all and experience only a hint of warmth
   3. some individuals have a reaction that is localized and then spreads either in a vertical line or diffused throughout a larger area
   4. some individuals find the sensation quite unpleasant
   5. some experience irritation, but it does not bother them

• Another friend of mine applied lavender (source unknown and questionable quality) on her daughter’s neck, and her daughter experienced what looked like chemical burns. Not horrible but clearly not good. It took about 2 weeks for the marks to heal. Lesson learned: The quality of the essential oil is crucial! This could possibly have happened with a high-quality oil as perhaps her daughter had very sensitive skin, but I suspect the quality of essential oil in this particular case.

• Undiluted can also look like – Yet another friend used lemongrass in water and then cleaned her house with it. Unbeknownst to me, she did not like to use gloves so she had cleaned her home with a relatively high dilution of Lemongrass in warm water. She experienced quite severe dermatitis. It took about 3 weeks to go away. Lesson learned: when using lemongrass or other similar oils to clean with, wear gloves!

• I have had hormone-related migraines for years now. Acupuncture treatment helps them to go away for quite a while but when I don’t have acupuncture in a while, they return. I have been using undiluted peppermint to ease the pain, provide a sense of cooling, and to serve as a vasoconstrictor. Sometimes, the peppermint prevents the migraine from becoming full-blown; other times, it simply takes the edge off enough so I can sleep it away. I use a fair amount of peppermint: basically, add about 7-10 drops in my palm and rub on my scalp, then 7 drops on finger tips to rub on my temples, then another 7 drops to rub on my neck up into the occipital bone area. I get huge relief from this. The peppermint feels great and the smell helps to ease tension.

• What I know is that this method of application for peppermint is not for everyone. What I also know, is that sometimes individuals stating that this is ‘crazy’ have obviously never had a migraine. For some individuals, this type of peppermint application would not feel good. In fact, to some individuals, peppermint may feel heating instead of cooling and hence further aggravate the migraine. Use caution if you plan on trying this. Use a little essential oil and see how it works for you. One thing for sure, always wash your hands thoroughly after applying any essential oil undiluted so as to avoid accidentally rubbing your eyes (ouch!) with essential oil/s on your hands.

• Ear infections: My son, Soren, exhibited possible otitis media symptoms at about 8 months of age. His symptoms included: unusual irritability, tugging at ear and inability to sleep through the night (highly unusual). He was being bottle fed which is one of the potential causes of otitis media. I applied 2 drops of Helichrysum italicum and Chamaemelum nobile each right behind both of his ears. I used my finger (both hands were washed before applying e/o’s) to rub the essential oils behind his ears and also placed my finger inside his ear. There appeared to be almost immediate relief, and by the next day, all signs of otitis media had disappeared.

Catty (2005) has found that Monarda fistula (purple bee balm, bee balm) essential oil and hydrosol to be highly effective in the treatment of otitis media. In two case studies she documented the following: One drop of M. fistulosa was applied undiluted to the index finger of the mother’s hand; the oil was then applied to the solar plexus and lung reflex points of the foot. Care was taken to apply the oil when the child was asleep or being put down for a nap to avoid the child playing with her feet, touching the oil and then getting that oil near her eyes or face. If this was not possible, then after application the feet were covered with socks. One drop was applied three times a day for the first three days and then twice daily for four more days. According to Catty, virtually all signs of the infection resolved within the first three to four days of treatment.

Catty noted that other potential methods of application include a compress to the external ear and temporal/mandibular areas, which can offer great relief from pain, swelling, and inflammation and can also facilitate the draining of fluid and infection. Her final comment was that ‘perhaps the most important observation is that in virtually every case of OM that she has treated, the use of essential oils not only cleared up the infection but also prevented any re-occurrence, even in those cases where the infection was chronic or had recurred on several occasions despite antibiotic treatment.

• Respiratory congestion: For just about everyone in my family and on clients when needed (when I practiced massage and/or reflexology), I have used undiluted essential oils of eucalyptus, rosemary, peppermint, lemon, tea tree, or ginger for easing respiratory congestion and supporting the immune system, particularly at night. Just a couple of drops are applied to the chest, feet, and/or neck. I have seen this method work over and over again. It is easy and harmless if done properly and in appropriate age groups (e.g., over the age of 5).

• Years ago, when I taught a class up in Alaska to a group of Young Living distributors, I noticed that when I began to do a massage on a few of them, using diluted essential oils, that both sides of their spine would go bright red from sensitization. It is possible that due to the overuse or misuse of RDT, they became sensitized to a number of different essential oils. Not good, but probably not as harmful as eating at a fast-food restaurant or eating processed food containing a host of synthetic additives and food colorings 🙂 Not advocating RDT here but simply recognizing that any method misused and/or overused or used for inappropriate reasons can create safety issues.

• I have used essential oils undiluted for things such as bruises, trauma to tissue caused by hockey puck hitting leg (German chamomile and Helichrysum), burns (Lavandula angustifolia or L. latifolia), scrapes, chigger bites (cape chamomile), ringworm on my dog (tea tree), shingles, infected acne spot (thyme ct. linalool) and about once a day I place a few drops of essential oil (lavender, rosemary, eucalyptus, sandalwood, etc.) to do direct palm inhalation and then rub anything left on my neck or chest. I have also used essential oils undiluted during reflexology sessions and for extreme pain in the neck and shoulder area with a warm compress during massage sessions. Finally, I have found that the use of more sedative oils on the soles of the feet can be quite helpful for individuals with insomnia or anxiety.

No matter what the response, however, undiluted application thankfully did NOT kill anyone nor did it ever cause any significant or long-lasting harm. It takes anywhere from 1 to 5 hours for irritation to dissipate with the exception of severe contact dermatitis or what may be more a ‘chemical’ burn. This can take 1-2 weeks to heal. And of course, once sensitized to an essential oil, it can take a lifetime to get over (both because of the physiological response and due to the memory-based association). Some may consider sensitization as long-term harm since they won’t be able to use the particular essential oil/s that caused the sensitization, but it is not long-term ‘harm’ per se. Simply a tragedy that an oil or two can no longer be used, in my humble opinion anyhow.

MAIN LESSON

So, the main lesson I have learned from all the above experiences and others I have had over the years is to respect the individual constitution and have a reason or purpose for applying the essential oils undiluted in the first place. Above all, I think it is important to know your essential oils. Know and understand their therapeutic actions, their chemistry, their nature, and even the plant that brings them forth, if at all possible.

When considering applying essential oils undiluted, ask yourself, for what purpose?

Professional Observations:

The undiluted application of essential oils is a highly controversial topic in aromatherapy. Practitioners and educators are divided on the issue. Current standards for aromatherapy education in the United States do not prohibit undiluted application.

According to Kurt Schnaubelt, author of Advanced Aromatherapy and Medical Aromatherapy: “It appears that most, if not all, of the sweeping generalizations, are not inspired by a thorough analysis of potential toxicity, but by a sentiment to err on the side of safety. The aim is to establish simple rules which would prevent a public, often perceived as less than intelligent, from incurring any and all adverse reactions with essential oils”. He recommends that a more balanced approach be adopted based on individual essential oils and their therapeutic efficacy and safety.

To utilize the undiluted application of essential oils effectively, a practitioner must be able to balance their understanding of the therapeutic benefits and applications of a given essential oil with possible concerns. From this knowledge base, a practitioner or individual is empowered to make a responsible professional decision to use undiluted applications when deemed necessary or appropriate.

My own experience and practice have taught me that there are indeed times when the undiluted application of essential oils is called for. We certainly should not live in fear but rather should work towards gaining a greater understanding of the potential benefits of this form of application so that it may be used wisely and for therapeutic benefit. I think that sometimes individuals can be so overly concerned with safety that they may forget to see the forest through the trees.

For further reading, I recommend:
The Healing Intelligence of Essential Oils by Kurt Schnaubelt.

COMPRESS

A hot towel cabinet is a valuable and convenient addition to any treatment room. This compact metal box is designed to maintain a regulated temperature and features a built-in UV bulb that helps inhibit bacterial growth, ensuring the towels remain sanitary.

Using a hot towel cabinet is straightforward; simply plug it into an electrical outlet and place it on a shelf that is out of the way. By preparing aromatic towels in advance, you can effortlessly incorporate the use of moist heat into your massage sessions, even during basic treatments. This simple tool enhances your client’s experience and provides additional therapeutic benefits without significantly altering your routine.

In general, aromatherapy hot towels are useful to:

• Relax tight or sore muscles
• Increase overall relaxation
• Improve local circulation
• Remove salt glows, scrubs, or masks
• Use as a welcoming or departing ritual just prior to or immediately following the massage session.

To create a compress using essential oils, follow these steps:

1. Fill a sink or large bowl with approximately 1 liter of water, adjusting the temperature to your preference (hot or cold).
2. Add 5 to 10 drops of your selected essential oils or ½ to 1 cup of hydrosol to the water. If desired, you may add a dispersant such as Solubol to help distribute the essential oils evenly. Just remember, if you are using Solubol, combine essential oils with Solubol first and then add to water.
3. Place a cotton or flannel cloth in the water and gently swish it around to ensure it absorbs the oil-infused water.
4. Wring out the cloth to your desired level of moisture.
5. Apply the compress to the area requiring treatment.
6. For a hot compress, leave it in place until it cools to body temperature. Then, repeat the process by soaking the cloth in the water again and reapplying. Repeat this process 3 to 4 times.
7. For a cold compress, refresh the compress every 5 to 7 minutes by re-soaking it in the cold water and reapplying.

Therapeutic dilution recommendation:
To 1 liter of water, place 5 to 10 drops of essential oil/s or 1 to 3 drops of essential oil directly on the compress.

Adding hydrosols: For adults, add 3 to 5 tablespoons of hydrosols to a liter of water at the desired temperature; for children, add 2 to 3 teaspoons of hydrosols per 1 liter of water.

Hot or Cold?

• Menstrual cramps (warm/hot)
• Respiratory congestion (warm/hot)
• Bruises (cold/warm)
• Skin inflammations (cold)
• Varicose veins (cold)
• Comfort care (warm)
• To bring down temperature/fever (warm)

HOT TOWEL CABINET

A hot towel cabinet is a valuable and convenient addition to any treatment room. This compact metal box is designed to maintain a regulated temperature and features a built-in UV bulb that helps inhibit bacterial growth, ensuring the towels remain sanitary.

Using a hot towel cabinet is straightforward; simply plug it into an electrical outlet and place it on a shelf that is out of the way. By preparing aromatic towels in advance, you can effortlessly incorporate the use of moist heat into your massage sessions, even during basic treatments. This simple tool enhances your client’s experience and provides additional therapeutic benefits without significantly altering your routine.

In general, aromatic hot towels are useful to:

• Relax tight or sore muscles
• Increase overall relaxation
• Improve local circulation
• Remove salt glows, scrubs, or masks
• Use as a welcoming or departing ritual, just prior to or immediately following the massage session

To prepare hot towels:
Fill a sink or small tub with hot water. Add 3 to 5 drops of your chosen essential oil and mix. Add 5 to 10 small hand towels. Soak towels for a few minutes, wring out well, and roll or fold. Place in the towel cabinet and let heat for at least 30 minutes prior to treatment.

Safety Note: When removing towels from the cabinet, be careful not to touch the inner walls with your hands, as you may get burned. Also, unfold the towels and test them on your inner forearm just prior to using them on your client. Although professional-grade cabinets are supposed to maintain a safe temperature, you may need to allow the towel to cool for just a moment before applying it to your client’s skin.

Watch: Quality of Essential Oils

INTRODUCTION

The concept of pure and natural or genuine and authentic within the aromatherapy profession is perhaps one of the most difficult concepts to ascertain. A pure essential oil is one that has been produced from a specified botanical source and has not been modified in any way whatsoever. According to Schnaubelt, a genuine essential oil means it is completely unaltered, and authentic means it is from a specified plant only. The adulteration of an essential oil may alter its unique therapeutic benefits as well as lead to an increased risk of adverse reactions.

The aromatherapy industry worldwide has adopted terms such as pure and natural, genuine and authentic, aromatherapy grade, true aromatherapy grade, therapeutic grade, and probably some others I am not yet familiar with. These terms are used by both discerning and non-discerning companies, making it difficult to judge an essential oil merely by the marketing material a company puts forth. All the terms above are loosely defined, and there are absolutely no regulations at this time that govern the aromatherapy essential oil industry.

Common Adulterations of Essential Oils

A number of methods may be employed to stretch, reconstruct, or otherwise alter an essential oil, and this is what is meant by adulteration. Adulterated essential oils pose a number of potential problems for aromatherapy, such as the potential increase in adverse dermal reactions (dermal irritation or sensitization) and the potential decrease in psychological benefits. Melissa, rose, sandalwood, and birch offer examples of essential oils that are commonly adulterated.

In Practice 3.1: Signs of Poor Quality

Signs of poor quality to watch for when purchasing essential oils include:

1. Essential oils are being sold at unreasonably low prices or all at the same price.

2. Rose, jasmine, sandalwood and melissa being sold in 1/2 to 1-ounce sizes. The average price of 1/2 ounce of rose otto essential oil is $195-200 and an ounce would be $400 or more. This makes it almost impossible to retail these oils in such a large quantity. Due to the expense of all of these essential oils, most aromatherapy companies will offer them either by the drop or in 1ml, 2ml, or 5ml quantities.

According to Burfield, “As far as adulteration is concerned, producers and distributors of essential oils are frequently painted as ‘the bad guys,’ but it should be pointed out that their oil customers frequently demand oils below the market price while still wanting to be told that they are authentic. In this climate, the honest oil trader may find it virtually impossible to survive on the margins he is allowed to make (many have already gone bust). For example, in the late 20th Century, lavender oil (Lavandula angustifolia) was being sold almost as a lost leader by many French producers as the market was unwilling to pay a realistic price; currently, the aroma industry is dominated by a handful of large and powerful international houses whose corporate buyers often attempt to drive raw material prices to impossibly low levels, not allowing workable profits to be made. This sets the scene for unethical practices.”

Common adulterations to essential oils include such techniques as:

• Alcohol or a vegetable oil is added to stretch the volume of essential oil.
• A synthetic chemical constituent is added to the main oil to increase its volume. Arctander (1994) reports that bergamot and lavender are commonly adulterated by adding synthetic linalylacetate or synthetic linalool, respectively.
• A cheaper essential oil is added to or distilled with the main essential oil. According to Arctander, melissa (Melissa officinalis) essential oil is often distilled with lemon, verbena, lemongrass, or citronella essential oil to increase the overall quantity of commercial melissa essential oil. The plant, melissa or lemon balm, contains less than .01 percent essential oil so it takes a vast amount of plant material to produce a small amount of melissa, making it an expensive oil to purchase.
• A completely synthetic product is produced in a laboratory and can be marketed as natural. This is common for both wintergreen and birch essential oils that are typically 100 percent synthetic methyl salicylate.
• A cheaper essential oil is substituted, for example, lavendin for lavender.

Basic Purity Tests

There are a number of ways in which you can test your essential oils for basic purity. The following are four basic tests you can do at home.

1. Place a drop of essential oil on a clean white sheet of blotting or watercolor paper. The essential oil should evaporate completely within a twenty-four to forty-eight-hour period, leaving no stain (unless the essential oil is colored, such as with some citrus oils and German chamomile) or reminiscent aroma. This method should not be employed with viscous essential oils, such as vetiver and sandalwood, as the more viscous the essential oil the longer evaporation will take. Citrus oils and others with a relatively high volatility are best suited to this basic test.

2. Place a drop of essential oil in a clear glass of water. If the water becomes discolored or turns milky, then the essential oil has been diluted with water and an emulsifier has been used to keep the essential oil and water together.

3. Place a drop of essential oil between two fingers on one hand and a drop of carrier or base oil between two fingers on the other hand and compare viscosity. There should not be the same oily texture to the essential oil as there is to the base oil. If it feels the same, then it is possible that the essential oil has been extended in a carrier or base oil. This process must be done by comparison and should not be utilized with the more viscous essential oils.

4. Our sense of smell is often underrated as a tool in determining the quality of an essential oil, but it is perhaps the most powerful tool we have, particularly once it has been trained and exercised. We are not typically accustomed to paying attention to our sense of smell so sometimes it takes practice and attention to strengthen it. In order to be able to effectively smell the quality of an essential oil, one could spend time smelling diverse aromas in the environment and a range of qualities of essential oils. For instance, first smell an excellent quality essential oil, then immediately smell a questionable or low quality essential oil (such as one sold for cheap in grocery stores or on-line). There should be a distinct difference in the quality and effect of the aroma. In time and with practice, your nose will become a great tool in determining the quality of an essential oil.

HOW TO SMELL AN ESSENTIAL OIL

Always approach essential oils with the awareness that they are very powerful. It is best to begin by holding the bottle or smell strip approximately four to five inches away from your nose and then move it upward toward your nose, depending on how much you can smell and how close you need it to be in order to enjoy its aroma. As you hold the smell testing strip or the bottle of essential oil below your nose, gently move it back and forth from the left nostril to the right or right to left. This way you receive the full spectrum of aroma the oil has to give. The aroma will expand as you continue to smell, with several layers to the aroma.

Natural, high-quality, genuine essential oils will be pleasant to the nose, whereas synthetics tend to attack the nose with a strong odor and then die off. Genuine essential oils continue to expand and develop as you smell them.

Chemical Analysis

The four basic tests for purity that you can practice at home are not considered full-proof methods by any means. Instead, essential oil buyers and sellers alike depend on a variety of scientific analysis to determine the composition and purity of an essential oil. We will discuss the two most common tests that are used to ensure the basic purity of essential oils via a chemical analysis of what the oil contains quantitatively and qualitatively.

Gas Chromatography

A gas chromatograph is a chemical analysis instrument that separates and identifies individual constituents within a given essential oil. Each chemical constituent of an essential oil will pass through the gas chromatograph instrument at different times and speeds. As each chemical is registered, it will produce some type of peak, from very short to very tall. A gas chromatography report reveals the peaks of different chemical constituents within a given oil; it does not, however, name the specific chemical constituent (e.g., linalool); for this, a mass spectrometer must be used.

Mass Spectrometry

Mass spectrometry is a technique that allows for the detection of compounds (chemical constituents) by separating ions by their unique mass. Mass spectrometry is utilized to identify specific compounds registered on the gas chromatography report. A typical mass spectrometer has three basic parts: an ion source, a mass analyzer, and a detector. Different molecules have different masses, and this fact is used to determine what molecules are present in a sample. An individual trained in reading GC/MS data will then clearly identify the exact constituents and their quantity (e.g., 5% linalool, 25% camphor, and so on) present within a given essential oil sample.

According to Burfield, “aromatherapists should not be too over-awed by the claims of essential oil traders, to the effect that GC-MS is the ultimate analytical tool. This simply is not true. When properly used it is certainly a powerful technique, but when used sloppily by untrained operators, the interpretation of results may be of limited value.” Interpretation of the information gained depends on the skill, experience, and knowledge of the individual who does the analysis. A GC-MS report may fail to reveal the age and quality of an essential oil, particularly in relation to the quality an aromatherapist is looking for. So, in general, although a GC-MS report on a given essential oil is incredibly helpful, it should not be used as the sole definitive guide to purchasing a high-quality, pure, unadulterated essential oil. Instead, it should be used along with an olfactory appraisal, confidence in the supplier and their intentions as a supplier (e.g., are they selling inexpensive essential oils to a general market or are they selling high-quality, typically high-priced essential oils specifically to practitioners of genuine aromatherapy?).

If you are interested in learning more about GC/MS, you can watch the following video:

For Examples of GC/MS reports
A company that offers exemplary information about each essential oil they sell would be Florihana in France. Here is a link to Clary sage. You can view the GC/MS on the right hand column where it says “Chromatography”.

To complete the Foundations of Aromatherapy Certification program, please submit your 5 Case Studies. Be sure you are including all the required elements and format indicated in the previous lesson.

You upload your case studies here. Please submit as Word documents (rather than pdf). Please do not submit Mac pages docs as we are unable to open them.

Recommended Suppliers

Essential Oil Companies

⇥ Original Swiss Aromatics: OSA’s
 essential oils are products of the plant organism. The way we offer essential oils is inspired by accepting oils as precious products of biological processes, cherished for their own beauty and brilliance rather than as industrial raw materials for the food or fragrance industry, standardized and diluted to be made economically acceptable. We will offer essential oils which, to the best of our abilities to ascertain, are truly genuine and authentic. This means nothing has been added nor taken out. It also means that no other natural substances have been added, that an oil is truly and exclusively from the plant that it claims to be.

⇥ Nature’s Gift: At Nature’s Gift, we carefully select pure essential oils from the four corners of the world. Our goal is to provide the finest quality pure and natural essential oils available today. We do not shop by price, nor do we buy from “mass market” suppliers, but rather from small distillers who either grow their crop themselves, or personally know and observe the farmers whose oils they sell. Most of our oils are either organically grown, or ethically wildcrafted with concern for the worldwide environment and ecosystem.

Enjoy a 10% discount from Natures Gift
Use Code: jade
Good for all sizes including bulks.
Excludes kits (birthing, beginner’s, care package, various skin solutions….), books, and gift certificates.

⇥ Florihana: 
At the foundation of our commitment to create the Florihana distillery were two main aims: respect for nature and development of highly therapeutic certified organic products for aromatherapists.

⇥ Lunaroma Aromatic Apothecary: Lunaroma offers pure organic essential oils of the highest quality. Our natural bath and body care products are handcrafted in small batches using only the finest quality aromatics, organic botanicals and base ingredients.

⇥ Essential Aura Aromatics:
 Essential Aura strives to be a leader in the distillation and supply of Organic Essential Oils for therapeutic aromatherapy. We promote the environmental sustainability of essential oil production. Developing direct relationships with both growers and other essential oil distillers, Essential Aura is in a position to provide exceptional quality essential oils. We provide the highest quality organic and wildcrafted essential oils we have found and since 1998 we have built our reputation on this effort.

⇥ Floracopeia: 
Floracopeia offers a large selection of well-known essential oils, as well as unusual, uncommon, and relatively unknown oils from unique botanical species.

⇥ Fragrant Earth: 
Fragrant Earth International is a long established company and our list has developed over the years, always aiming to meet the needs of practitioners and therapists world-wide.

Dried Herbs (Bulk)

⇥ Pacific Botanicals: We have been growing high quality organic medicinal herbs in the Applegate Valley since 1979. We know the types of herbs that do well here and have selected the various varieties to fit our microclimate and to achieve maximum potency. You can count on us to know the herbs we grow and sell; from the seed that we use, to the starts in the green houses, to our pristine growing environment, to the organic nutrients we add to the soil, to the perfect time for harvest and conditions for shipment. In addition to our own farm we have built good working relationships with many other organic growers in the U.S. and around the world. We have been sourcing herbs from them for many years. We only do business with growers that meet our high standards of quality. We are certified organic in growing and processing by USDA and Oregon Tilth.

⇥ Mountain Rose Herbs: 
Since 1987 Mountain Rose Herbs has been known for its uncompromising commitment to organic agriculture and steadfast focus on the pure aesthetics and freshness of botanical products.Throughout all of these magnificent and developmental years we have always put an emphasis on conducting business in an ethical, responsible, clear, and ecological way; hoping to pave a medium for other blossoming green companies.

⇥ Oregon’s Wild Harvest: 
Committed to naturally healing the body and earth using the most holistic and sustainable growing and processing practices to safely retain the freshest, purest and most effective properties of whole herbs.

Hydrosols

Most aromatherapy companies or essential oil suppliers listed above also sell hydrosols. We will continue to add to this list of artisan distillers to support local plant cultivation, sustainable wild-crafting and small batch production.

⇥ Morning Myst Botanicals: 
Offering over 50 Varieties of Certified Organic Hydrosols. All of our hydrosols are produced here on our farm, by us personally. You are buying DIRECT FROM THE DISTILLER.

⇥ Phibee Aromatics: PhiBee Aromatics is a family run business (named after our girls), born out of our love and passion for the native plant world.

Vegetable Oils/Herbal Oils/Aloe vera gel

⇥ Jedwards International
: BULK Supplier of Certified Organic and Conventional Specialty Oils, Essential Oils, Butters, Waxes, and Botanicals

⇥ Mountain Rose Herbs: 
Since 1987 Mountain Rose Herbs has been known for its uncompromising commitment to organic agriculture and steadfast focus on the pure aesthetics and freshness of botanical products.Throughout all of these magnificent and developmental years we have always put an emphasis on conducting business in an ethical, responsible, clear, and ecological way; hoping to pave a medium for other blossoming green companies.

⇥ The Jojoba Company: Purchase your jojoba oil here.

⇥ Essential Wholesale: We offer the highest quality natural Soap Making Supplies, Aromatherapy and Cosmetic Making Ingredients. With over a thousand different items to choose from, including Cosmetic Bases, Essential Oils, Carrier Oils, Exotic Butters & Waxes, Cosmetic & Soap Making Ingredients, Fruit & Herbal Extracts, Organics and so much more.

⇥ Banyan Botanicals
: A resource for Ayurveda and premium quality Ayurvedic products made from certified organic herbs sustainably sourced and fairly traded. Excellent Sesame oil and Ayurvedic herbs.

⇥ Vermont Soap Company: 
Has some really awesome bulk certified organic (and no latex) shea butter.

⇥ New Directions
: Supplies a range of organic bases/oils/butters.

⇥ Healthy Traditions: 
Gold Label Virgin Coconut Oil is our highest quality coconut oil. This premium Virgin Coconut Oil is handcrafted by family producers in the Philippines using traditional methods passed down from previous generations. We were the first ones to export Virgin Coconut Oil from the Philippines to the United States back in 2001.

FOR VERY LARGE PURCHASES OF VEGETABLE OILS, HERBS, EXTRACTS, HYDROSOLS (PER ANNUM)

⇥ Praan Naturals:Natural Sourcing specializes in the procurement and supply of an extensive range of natural, conventional and organic ingredients for cosmeceutical, fragrance & perfumery, spa, massage and aromatherapy applications.

Cold Pressed Seed Oils

⇥ Botanic Innovations: Botanic Innovations produces a broad range of highly specialized oils from non-GMO fruit, vegetable, grain and herb seeds. These life-nourishing all-natural ingredients have broad applications in a variety of products across several industries. Our advisors have formulated proprietary seed oil that add powerful health benefits to dietary supplement products. Some of our products are also used in animal care products, as cosmetics, as functional food additives, and as all-natural industrial lubricants.

Beeswax

⇥ New Directions: 
Supplies a range of organic bases/oils/butters.Organic Raw Honey and Beeswax

⇥ Jedwards: Offers bulk beeswax.

Pippettes

⇥ SKS Science: Bulk disposable pipettes.

⇥ Rachel Supply: Small quantites and bulk pipettes.

Bottle Companies

⇥ SKS Packaging: 
SKS is a supplier, consultant and designer of plastic bottles, glass bottles, plastic jars, glass jars, metal containers and closures for your packaging needs. Our online selections of containers and closures is extensive and priced right so that you are getting the best selection of products at the best prices.

⇥ Specialty Bottle: 
Specialty Bottle is a national supplier of glass, plastic and metal containers. We service over 30,000 customers throughout the United States and Canada. Many of our customers are in the gourmet food, natural products and candle industries.

⇥ Berlin Packaging: 
Quality plastic and glass bottles, perfume bottles, jars, vials, brushed aluminum, bags and bottle accessories

Print/Business Cards/Labels

⇥ Online Labels.com: Largest selection of label shapes and designs. Also has label design software. Order polyester labels, they are waterproof!

⇥ Vista print: Business cards and other print material