Frequently Asked Questions
Frequently Asked Questions
- What is the ancient history of essential oils?
- Modern rediscovery
- What are essential oils?
- What are the different types of oils?
- How are essential oils used?
- What makes essential oils therapeutic-grade?
- Toxic and adulterated
oils and mislabeling - The fragrance factor
- Brief introduction to essential oil chemistry
- Basic Chemical Structure
What is the ancient history of essential oils?
Essential oils are the oldest and some of the most powerful therapeutic
agents know to man. They have a millennium-long history of use in healing
and in religious ceremony throughout the ancient world, besides their
use as fragrance. Some, particularly frankincense, are cited repeatedly
in many Judeo-Christian and Muslim religious texts. They were used
to cure every ailment “from gout to a broken head.” Others,
such as myrrh, lotus, and sandalwood oils were widely used in ancient
Egyptian purification and embalming rituals. Still others, such as
clove and lemon, were highly valued as antiseptics hundreds of years
before the discovery of modern antiseptics.
Aromatics, as they were called, were some of the most prized treasures
of the ancient world - they were traded for gold, silver, and even
slaves. To understand how valuable essential oils were in ancient Egypt,
records show that when Tutankhamen’s tomb was opened in 1922, 350 liters
of oil were discovered in alabaster jars. Amazingly, the plant waxes
had solidified around the openings of the jars, sealing and preserving
the oils!
The National Geographic reported in October of 1985 that almost 1,000
years before Christ, dynasties of the ancient world were fighting over
the lucrative incense market. Caravans of 3,000 camels transported
costly frankincense along the Frankincense Trail, a 2,400-mile-long
road that stretched from southern Arabia to the coast of Israel.
It appears that the ancient Egyptians were the first to recognize
the therapeutic potential of essential oils. They created fragrances
for personal use as well as for ritualistic and ceremonial use in the
temples and pyramids. In 1817, the 870 foot long Ebers Papyrus, dating
back to 1500 B.C., was discovered. It listed over 800 herbal prescriptions
and remedies. Many mixtures were composed of myrrh oil and honey. Myrrh
was most often used for embalming, due to its effectiveness in preventing
bacterial growth.
The physicians of Greece came to Egypt to learn about the oils. Even
Hippocrates attended the school of Kos.
The Romans used essential oils by diffusing them in their temples
and political buildings. They were fond of soaking in oil-scented baths,
then receiving a fragrant oil massage.
The ancient Arabian people began to study the chemical properties
of essential oils. They developed and refined the distillation process.
Europeans began producing essential oils in the 12th century. During
the Plague of the 15th century, certain thieves robbed the dead without
becoming infected. Finally, four thieves were captured in Marseilles,
France, and charged with robbing the dead and dying victims of the
plague. At the trial, the magistrate offered them leniency if they
would reveal how they managed to avoid contracting the dreaded infection,
in spite of their close contact with infected corpses. It was disclosed
that these thieves were perfumers and spice traders who had rubbed
themselves with a concoction of aromatic herbs (cinnamon, clove, and
oregano).
When the great library was burned in Alexandria during the Dark Ages,
much of the knowledge of essential oils and their uses was lost. It
was only through the cosmetic and perfume industry that some of the
valuable science of aromatherapy began to resurface.
The modern rediscovery of the value of essential oils is attributed
to French cosmetic chemist, RenÈ-Maurice GattefossÈ, Ph.D. In July
of 1910, a lab explosion set him aflame. After extinguishing the flames,
he discovered that his hands were developing gas gangrene. But just
one rinse with lavender essential oil stopped the horrible process.
Healing began the next day.
This incident prompted Dr. GattefossÈ to research the healing compounds
of essential oils. His research spurred the clinical use of essential
oils.
As a result, French physician, Dr. Jean Valnet, used essential oils
as antiseptics and antibiotics on the battlefields during World War
II. After the war, he documented his clinical results in his book,
The Practice of Aromatherapy. He also shared his knowledge with his
student, Daniel PÈnoÎl, M.D., who later co-authored the first definitive
medical textbook on the chemistry and clinical application of essential
oils: L’aromathÈrapie exactement
Essential oils are highly concentrated natural plant extracts; a drop
or two can produce significant results. An entire plant, when distilled,
might produce only a single drop of essential oil. That is why their
potency is far greater than dried herbs. Pressing or distillation extracts
the subtle, volatile liquids (meaning they evaporate quickly) from
plants, shrubs, flowers, trees, roots, bushes, and seeds, that make
up essential oils.
Essential oils are the life-blood of the plant, protecting it from
bacterial and viral infections, cleansing breaks in its tissue and
delivering oxygen and nutrients into the cells. In essence, they act
as the immune system of the plant. That is why they are so essential
to the plant — without them, plants could not survive.
In the human body, they have a similar action — such as transporting
valuable nutrients to the cells; increasing oxygen intake, and digesting
toxic waste in the blood. This is because the three primary elements
- carbon, hydrogen and oxygen-are common to both human beings and essential
oils. This shared chemistry makes essential oils one of the most compatible
of all plant substances with human biochemistry.
Not only that, but the lipid-soluble structure of essential oils and
the fact that they have a protein-like structure similar to human cells
and tissues makes them even more compatible with human tissue.
Essential oils are very different from vegetable oils (also called
fatty oils), such as corn oil, olive oil, peanut oil, etc. Fatty oils
are produced by pressing nuts or seeds. They are quite greasy, are
not antimicrobial nor help transport oxygen, and will go rancid over
time. Essential oils, however, are not greasy nor do they clog the
pores like vegetable oils can.
Essential oils are highly complex substances. They are mosaics of
hundreds - even thousands - of different natural chemicals. The average
essential oil may contain anywhere from 80 to 400 known chemical constituents.
Many oils contain even more, occurring in minute quantities - but all
contributing to the oil’s therapeutic effects. It requires years of
study to understand these constituents, their activity and functions.
Different varieties of the same oil can have widely different therapeutic
actions, depending on their chemistry. For example, basil high in linalool
or fenchol is primarily used for its antiseptic properties. However,
basil high in methyl chavicol is more anti-inflammatory than antiseptic.
A third type, basil high in eugenol, has both anti-inflammatory and
antiseptic effects.
In addition, essential oils can be processed in different ways, which
dramatically effects their chemistry and medicinal action. Oils that
have been redistilled two or three times are obviously not as potent
as oils that have been distilled only once. Also, oils that are subjected
to high heat and pressure in processing have an inferior profile of
chemical constituents, since excessive heat and temperature fractures
and breaks down many of the delicate aromatic compounds within the
oil — compounds that are responsible for much of the therapeutic action
of the oil.
Of even greater importance is the fact that some oils are thinned
or cut (i.e. adulterated) with synthetic chemicals.
What are the different types of oils?
Essential oils are obtained by different methods — distillation being
the most familiar. There are four types of essential oils:
- Absolutes vs. concretes
- Expressed
- Solvent-extracted
- Steam-distilled
Absolutes are “essences,” rather than “essential” oils.
They are generally obtained from the extraction of a concrete with
alcohol. A concrete is the solid waxy residue derived from hexane
extraction of plant material (usually the flower petals).
This method of extraction is used for botanicals where the fragrance
and therapeutic parts of the plant can only be unlocked using solvents.
These are not to be used internally, as traces of petrochemicals remain
in the oil. Jasmine and neroli are examples of absolutes.
Expressed oils are pressed from the rind of fruits (usually citrus).
Tangerines, grapefruits, lemons and oranges are produced by this method.
Technically speaking, these are not “essential oils” - they
are expressed oils, but they are highly regarded for their therapeutic
properties, none the less. It is best to use only organically grown
crops for this method, since pesticide residues, especially highly
toxic, oil-soluble carbamate and chloride-based petrochemicals, can
become highly concentrated in the oil.
Solvent extration involves the use of oil-soluble solvents, such as
hexane, dimethylenechloride, and acetone. There is no guarantee that
the finished product will be free of solvent residues.
Steam distillation is the oldest and most traditional method of extraction.
Plant material is inserted into a cooking chamber, and steam is passed
through it. After the steam is collected and condensed, it is processed
through a separator to collect the oil. The amount of pressure used,
the amount of time the plant material is steamed and the material the
steam chamber is constructed of contribute a great deal to the quality
of the oil (or lack of).
Historically, there have been three models for using essential oils:
the French, the German, and the English methods.
The English traditionally dilute a small amount of essential oil in
vegetable oil and massage the body to relax and relieve stress.
The French prefer to ingest (swallow) therapeutic-grade essential
oils. Many French practitioners have found that taking the oils internally
is highly effective.
The Germans recommend inhalation of the essential oils. There is good
reason for this - research has shown that these aromatic compounds
can exert strong effects on the brain, especially on the hypothalamus
(the hormone command center of the body) and the limbic system (the
seat of emotions). Some essential oils can dramatically increase oxygenation
and activity in the brain. Oils also increase ozone and negative ions,
which inhibit bacterial growth. Essential oils can make chemicals non-toxic
by fracturing their molecular structure. European scientists have found
that essential oils work as natural chelators, bonding to metallics
and chemicals and carrying them out of the body. Diffused essential
oils make outstanding air filtration systems, helping to remove dust
particles from the air and destroying odors from mold, cigarettes,
animals, etc.
When diffused, the oils reach the brain by means of the olfactory
system. The olfactory membranes have about 800 million nerve endings
that receive micro-fine, vaporized oil particles. They carry them along
the axon of the nerve fibers and connect them with the secondary neurons
in the olfactory bulb. The impulses are then transported to the limbic
system and the olfactory sensory center at the base of the brain. Then
they pass between the pituitary and pineal gland and move to the amygdala
- the memory center. The impulses than travel to the gustatory center
where the sensation of taste is perceived.
The best method of application depends on the need. In some cases,
inhalation might be preferred over topical application if the goal
is to induce weight loss or balance mood and emotions. In other cases,
topical application would produce better results, as in the case of
muscle or spinal injuries. For indigestion, peppermint oil taken orally
is very effective. Yet peppermint can also produce the same results
when massaged on the stomach. In some cases, all three methods of application
(topical, inhalation and ingestion) are interchangeable and may produce
similar benefits.
The two most common methods of essential oil application are cold-air
diffusing and neat (undiluted) topical application. Healing response
is greatly enhanced when essential oils are incorporating into the
disciplines of reflexology, Vita Flex, acupressure, acupuncture, auricular
techniques, lymphatic massage, spinal touch, and the Raindrop Technique.
What Makes Essential Oils Therapeutic-Grade?
Essential oils come from various parts of plants - the seeds, bark,
leaves, stems, roots, flowers, and fruit. The oils can be distilled
from the plant material or extracted. The majority are distilled.
The key to producing a therapeutic-grade essential oil is to preserve
as many of the delicate aromatic compounds within the essential oil
as possible - elements that are very fragile and destroyed by high
temperature and high-pressure. Contact with chemically reactive metals
(i.e., copper or aluminum) is another danger to the fragile aromatic
compounds in oils.
To insure a high grade of essential oil, it is imperative to use stainless
steel cooking equipment at low pressure and low temperature for long
periods of time.
The purity of an essential oil is also determined by its chemical
constituents. There are many variables that can affect these constituents.
These can include:
- Soil conditions
- Quality of fertilizer and whether it was organic
or chemical - Region
- Climate
- Altitude
- Harvest season
- Harvest methods
- Distillation process
- The part or parts of the plant used for distillation
One plant can
produce several different chemotypes (biochemical variations). The
chemotypes vary according to climate, altitude and growing conditions.
For example, the later thyme is distilled in the growing season (i.e.,
late summer or fall), the more thymol the oil will contain. If it
is distilled in the early summer, thymol levels will be very low;
hence, the oil will be less effective, if at all.
A toxic oil is worse than an ineffective oil, however. Essential oils
grown with agrochemicals can be dangerous. Pesticides, herbicides and
chemical fertilizers can react with the essential oil during distillation,
producing toxic compounds. And synthetic oils not only lack therapeutic
benefits, but also carry risks.
Natural essential oils contain hundreds of different chemical compounds,
many of which have not been identified yet, but which bring important
therapeutic properties to the oil. Although chemists have managed to
recreate some of the constituents and fragrances of oils, there are
many molecules and isomers that are impossible to manufacture in the
laboratory. There simply are no substitutes for the purest essential
oils.
While there are no regulations in America, a set of standards has
been established in Europe that outlines the chemical profile and principal
constituents that quality essential oils should have. These standards
are known as AFNOR and ISO (Association French Normalization Organization
Regulation and International Standards Organization). They are guidelines
that help buyers differentiate between a therapeutic-grade essential
oil and lower grade oils with similar chemical makeup and fragrance.
The only company with AFNOR certification in America, to date, is Young
Living Essential Oils, whose oils are constantly being analyzed and
graded according to the AFNOR standards.
The AFNOR certification is one of the most reliable indicators of
essential oil quality. It is a stringent standard that differentiates
true therapeutic-grade essential oils from similar (but inferior) Grade
A essential oils. It was developed in France by chemist Hervi Casabianca,
Ph.D., who recognized that the constituents within an essential oil
had to occur in certain percentages in order for the oil to be considered
therapeutic. He and other scientists and doctors combined their research
to create the AFNOR standards.
With this indicator, oils can be checked to see if they meet AFNOR
standards. If some constituents are too high or too low, the oils cannot
be AFNOR or ISO certified. For example, if two or more marker compounds
in an essential oil fall below the allowable range, the oil cannot
meet the AFNOR standard. It cannot be called therapeutic-grade essential
oil, even though it is still Grade A quality.
Without AFNOR standards, it is difficult to tell a therapeutic-grade
essential oil from a Grade A essential oil. As an example, Lavender
oil is frequently produced from hybrids, yet claimed to be genuine.
AFNOR standards help distinguish true lavender from various species
of hybrid lavender (actually lavandin). Tasmania produces a lavandin
that mimics the chemistry of true lavender. The only way to determine
its origin is by analyzing the chemical fingerprint using high-resolution
gas chromatography and comparing it with the AFNOR standard for genuine
lavender.
Analyzing an essential oil by gas chromatography is complex and highly
technical. The injection mixture, film thickness, column diameter and
length, and oven temperature must fall within certain parameters. Most
labs in the United States use equipment that is only adequate for analyzing
synthetic chemicals and marker compounds in vitamins, minerals and
herbal extracts, but cannot properly analyze the complexity of natural
chemicals found in essential oils.
At the present time, there are only two companies that use the proper
machinery and test standards for AFNOR essential oils analysis (considered
the gold standard) - Flora Research and Young Living Essential Oils.
But even gas chromatography (GC) has limitations. It is very difficult
to distinguish between natural and synthetic compounds using GC analysis.
This is why oils must be analyzed by a technician specially trained
in the interpretation of a gas chromatograph chart. He/she can examine
the entire chemical fingerprint of the oil, and all the important clues,
to determine if the oil is adulterated or pure.
Toxic and Adulterated Oils and Mislabeling
Adulteration of essential oils is becoming more and more common these
days. As the demand for them grows, the supply of top-grade essential
oils dwindles. The temptation to thin the oils with solvents, then
add synthetic fragrance is great. In the last several years, France
exported 100 times more lavender oil than it produced. This can only
be possible if the oil is being thinned.
True lavender oil (Lavandula angustifolia) is expensive and difficult
to find. Most of the lavender oil sold in America today is actually
the hybrid, Lavandin, grown and distilled in China, Russia, France
and Tasmania. It is shipped to France and cut with synthetic linolyl
acetate to improve the fragrance. Then propylene glycol, DEP or DOP
(odorless solvents) are added and it is labeled as Lavandula officinalis.
Many times it also goes through heat processing to burn off the camphor
the hybrid contains and then thinned with more linolyl acetate to appear
as lavender. These bottles line the shelves of health food stores,
herb shops and department stores, selling for $5.00 to $7.00 per half
ounce. Unfortunately, most consumers don’t know the difference.
Frankincense is very commonly adulterated. This essential oil requires
12 hours of steam distillation from expensive resin to be therapeutic-grade.
Inexpensive frankincense oil that sells for $25 an ounce or less, is
invariably distilled with alcohol or other solvents.
Lemon oil is another commonly adulterated essential oil. Terpene waste
fractions left over from the industrial refining of citrus products
and/or synthetic limonene is often purchased from chemical houses and
used to dilute or “extend” genuine lemon oil. Since terpenes
and limonene naturally occur in lemon oil, even a gas chromatograph
cannot distinguish between synthetic and natural limonene.
The most commonly adulterated oils include frankincense, myrrh, lemon,
peppermint, cistus, helichrysum, lavender and birch or wintergreen,
although all essential oils may be adulterated easily.
Most consumers do not know that adulterated oils can cause rashes,
burning, and skin irritations. The petrochemical solvents in them can
cause intense allergic reactions and toxic accumulations. And that
they are devoid of any therapeutic benefits whatsoever.
It is very important to know about the integrity of the company from
whom you are buying the essential oil. It is also very important for
the company or vendor to know about the integrity of the oil.
Many vendors do not realize that the essential oils they sell come
from chemical laboratories. There are huge chemical companies on the
East Coast that specialize in the duplication of essential oils. For
every kilo of pure essential oil that is produced, there are between
10 and 100 kilos of synthetic oils created.
In addition, some bottles do not contain the oil stated on the label.
Oils marked as “clove” may be distilled from the leaf instead
of the bud. Clove leaf oil is less expensive but does not have the
same chemistry or therapeutic properties as clove bud oil. Many times,
essential oils marked “cinnamon” are actually “cassia.” Birch
oil is often really Wintergreen — at least in this case, the oils
are nearly comparable. But, very often, synthetic methyl salicylate
is added to low-grade birch or wintergreen oils to “improve” its
quality.
As you can see, labeling can be very misleading - considering there
is no agency responsible for certifying that an essential oil is therapeutic
grade. There is no requirement that ingredients be listed on essential
oils bottles. Therefore, unscrupulous manufacturers can literally get
away with making any claims they want. Once again, it is up to the
consumer to educate himself or herself and know the difference.
Aromatherapy means to treat with aroma through inhalation (although
it also encompasses the topical application of essential oils). Research
has shown that we respond to aroma within one to three seconds. Scientists
are just beginning to explore how aroma reaches and influences the
human brain, emotions and body.
An oil’s fragrance is created when vapor evaporates from it. The heavier
the molecular weight of the oil, the less volatile it is (the less
it will evaporate). Oils with lighter molecular weights, evaporate
or ‘flash off’ quickly. Therefore, the scents of lavender or geranium
last only about 20 minutes. Heavier oils such as myrrh, frankincense,
sandalwood, and patchouly evaporate slower, and therefore, their scent
lasts longer.
As the molecules in a fragrance evaporate into the air and are inhaled,
olfactory membranes (protected by the mucous lining of the nose) capture
them. These membranes are lined with receptor cells that can be considered
hair-like extensions of nerve fibers. Each fragrance molecule fits
itself into specific receptor cells, like a puzzle piece. The stimulation
by odor molecules causes the receptors to trigger electrical impulses
to different parts of the brain. These nerve impulses are transmitted
to the limbic system of the brain. The brain then sends more impulses
to different parts of the body, depending on type and function.
The limbic system is directly connected to the parts of the brain
that control heart rate, blood pressure, breathing, memory, stress
levels, and hormone balance. Because of this, essential oils can have
profound physiological and psychological effects.
Have you ever noticed that a scent or fragrance can instantly evoke
a memory or an emotion on an unconscious level? This is because the
sense of smell is the only one of the five senses that is directly
linked to the limbic lobe of the brain - the emotional control center.
Emotions such as anxiety, depression, fear, anger, as well as joy all
emanate from this region.
The limbic lobe can also directly activate the hypothalamus - the “master
gland.” The hypothalamus functions as the hormonal control center
of the body. It releases chemical messengers that affect the production
of growth hormones, sex hormones, thyroid hormones, and neurotransmitters.
Essential oils, through their fragrance and molecular structure, can
directly stimulate both the limbic lobe and the hypothalamus. In this
way, essential oils can exert a profound effect on the body and the
mind.
Brief Introduction to Essential Oil
Chemistry
Essential oils are made up of many chemical constituents. No two oils
are alike in their structure or their effects. Below is a list of some
of the main constituents found in essential oils:
- Alcohols
- Aldehydes
- Esters
- Ethers
- Ketones
- Phenols
- Terpenes
Each of these can be broken down into numerous smaller
units. Take terpenes, for example. This classification includes monoterpenes,
sesquiterpenes, sesquiterpene lactones, Di-terpenes, etc. Listing
them all is beyond the scope of this brief overview.
Each constituent has its own action, or effects. For example, the
ketones found in lavender, hyssop and patchouly, stimulate cell regeneration.
Whereas, phenols, found in oregano and thyme oil, are highly antimicrobial.
Because the chemistry of essential oils is very complex, essential
oils are diverse in their effects. This also supports their antimicrobial
effects, because the wide variety of antiseptic compounds in essential
oils makes the mutation of microorganisms extremely difficult. In l985,
Dr. Jean C. Lapraz stated that no microbe could survive in the presence
of the essential oils of cinnamon or oregano.
Essential oils molecules are made up primarily of carbon, hydrogen,
and oxygen.
The aromatic constituents of essential oils are built from hydrocarbon
chains (carbon and hydrogen atoms). They are normally joined together
in ring-like chemical structures. The chains are held together by carbon
atoms linked together. Oxygen, hydrogen, nitrogen, sulfur, and other
carbon atoms attach at various points of the chain, to make up the
different oils.
The aromatic-ring structure of essential oils is much more complex
than the simpler, linear carbon-hydrogen structure of fatty oils. Essential
oils also contain sulfur and nitrogen atoms that fatty oils do not
have.
The basic building block of many essential oils is a five-carbon molecule
called an isoprene. Most essential oils are built from isoprene. This
is the building block that makes up the terpenoids.
When two isoprene units link together, they create a monoterpene;
when three join, they create a sesquiterpene; and so forth. Triterpenoids
are some of the largest molecules found in essential oils. They consist
of 30 carbon atoms — or six isoprene units linked together.
Different molecules in the same essential oil can exert different
effects. For example, the azulene in German chamomile has powerful
anti-inflammatory compounds. The bisobolol German chamomile also contains
has sedative and mood-balancing properties. Other compounds in German
chamomile perform still different functions, such as speeding the regeneration
of tissue.
This is because the chemical structure of an essential oil determines
its function. Phenols generally create antibacterial activity. Carvacrols
have anti-inflammatory activity and Limonines are antiviral.
A single species of plant can have several different chemotypes based
on its chemical composition. A plant such as basil grown in one area
might produce an essential oil with a completely different chemistry
than basil grown in another location.
This discussion is meant as an introduction to a vast field of study
that is beyond the scope of this website. For more information, the
following publications may be helpful:
- Essential Oil Chemistry by D.
Williams - Lavandes and Lavandins by Christiane Meunier, Aix-en-Provence
1985. - Phytochemical Dictionary edited by Jeffrey B. Harborne and Herbert
Baxter - Journal of Essential Oil Research (JEOR) Tel: (630) 653-2155
Fax: 630 653-2192 - Aromatherapie by Jean Valnet, M.D., Healing Arts
Press, Rochester, VT, 1982 - Aromatherapy by RenÈ-Maurice GattefossÈ,
Ph.D., Girardot, Paris 1937. - L’aromathÈrapie exactement by Daniel
PÈnoÎl, M.D., and Pierre Franchomme.
