Written and researched by: Martin Watt Cert Phyt.
Those training courses which place great emphasis on therapeutic or toxicological actions of essential oils being caused by single chemicals occurring in the oil are wrong. Why ?
To attribute the broad spectrum of therapeutic actions inherent in most essential oils, based on individual chemical constituents is wrong. If you say that 'because lavender contains linalool (a proven sedative), that therefore the whole essential oil will have the same therapeutic actions as attributed to linalool’, is highly misleading and far too simplistic.
When we look at the number of essential oils containing common chemicals such as linalool, in fact we see that they can have very different fragrances as well as actions. Perhaps the best instance is linalool type basil oil. The fragrance is still basil-like and some would say it is a mild stimulant. It is also most unlikely, that basil-CT linalool, will achieve the same kind of mental relaxation as a lavender oil containing similar, or even less volumes of linalool.
Genuine natural oils can have colossal variations in their chemical make up, and yet there may be little difference in their fragrance. This is because the characteristic fragrance of an essential oil, is often found in the minute traces of odoriferous chemicals, and not necessarily in the major components. The food and flavour trades are well aware of this, and most of them only use the fractions containing the most potent fragrance or flavour molecules. Frequently these molecules only represent 0.5-5% of the whole oil.
Assigning actions to an essential oil based on the classification of its major component; i.e. aldehydes are anti inflammatory, alcohols are relaxing, ketones are neurotoxic. This classification system is now used on many aromatherapy training courses, and yet it is extremely misleading and frequently potentially dangerous. I have seen in course notes from so called ‘reputable & recognised’ training courses; "aldehydes are more or less skin irritants", this is wrong. Some aldehydes are common food ingredients, while others such as cinnamic aldehyde are severe skin irritants. "Ketones are neurotoxic", as a general classification this is utter nonsense. Ketones are common food ingredients and the essential oils such as sage and pennyroyal are permitted food additives. "Terpenoid groups have particular therapeutic properties", this is unbelievably silly as terpenoids are a vast group of chemicals with widely varying properties.
It is totally wrong to attribute potential actions and adverse effects of essential oils based on broad chemical classifications. Essential oils are highly complex mixtures of natural chemicals, and in fact many are so complex that they still can not be fully re-created by chemists. Many contain large amounts of unidentified chemicals and therefore the actions of such individual chemicals are unknown. As already stated, it is the trace chemicals which contain the most active fragrance and flavour molecules, and it is a fair assumption that many highly active therapeutic substances also only occur in trace amounts. Man can re-create the fragrance of many essential oils, but such a product does not contain the hundreds of trace chemicals (with their synergistic and perhaps potent actions) as the real thing.
The natural chemicals making up essential oils frequently display isomerism. This is another reason that it is wrong to say that "because an oil contains thujone, that all oils containing thujone will therefore be toxic". Thujone does not exist as one chemical, it has isomers one of which is 4 times more toxic than the other. Some oils contain a lot of one isomer and other oils a lot of the opposite isomer. Therefore you must know precisely which isomer exists in the respective oil, and what the precise actions of the different isomers are. Even then you can not be certain of the effects of a potentially toxic isomer, due to the modifying effects caused by the numerous other chemicals occurring in the whole oil.
The lesson to be learnt from this is; consider the known data on the actions of the whole essential oil first. Chemistry does have its uses when looking at essential oils, but it should always be secondary to the knowledge of the effects of the whole oil.
Students are being told that the action of particular oils are due to x, y, or z chemicals. However most aromatherapy schools do not have a clue what the oil they are using actually consists of. How is it that some of these schools who are unknowingly using semi-synthetic oils such as lavender and geranium, still seem to get good therapeutic results? Is it perhaps because of utmost importance may be what the oil smells like, rather than its precise chemical composition? The client-therapist placebo effect is also of equal importance, but 'placebo' tends to be a rude word in complementary medicine.
So why fill students heads with a lot of theoretical chemistry, when logic tells us that in practice it can not be correct? I can answer my own question here; it is that the people providing such material on their courses have not studied the subjects they are teaching carefully enough. They therefore follow trend setters like sheep and include misleading information on their courses, to fill time and have their courses 'recognised' by trade associations who provide fallacious validation.
The seemingly desperate need by training organisations to delve into areas of chemistry which are of little relevance to the use of natural essential oils is a terrible shame. It is leading us down the same paths that conventional medicine and the pharmaceutical trades have trodden. It would be more acceptable if real experts in the trades associated with essential oils were used in aromatherapy training. People such as scientists who have proved that synergistic action really does exist, dermatologist's who work every day with cases of adverse reactions to products including essential oils. However no, many course providers would rather stick to the pharmacists and others trained in the chemical sciences, who are not expert in the specific sciences of essential oils. 'Well they are cheaper aren't they? we must bear in mind our training course in Bermuda is going to cost a lot?we must get that other house in the south of France this year, and oh yes?don't forget we must go on the French aromatherapy holiday'.
Students from well known schools tell me they were told; "you can't
be an aromatherapist unless you know the correct Latin names". This
is complete and utter nonsense, I have come across few schools that knows
the correct botanical name of even a fraction of their oils.
Most plants used for essential oil production whether they are wild, or
cultivated crops, consist of numerous sub-varieties that can have wildly
different chemical compositions. Therefore if you are taught that
for instance tea tree oil must be Melaleuca alternifolia this is not strictly
correct. There are a number of sub-varieties of alternifolia
which are used for tea tree oil. This is why the Australian governments
standard for tea tree oil does not just specify alternifolia but adds
"oil of Melaleuca, terpinen-4-ol type".
Commercial developments in essential oil bearing crops have been going on for well over a century, with constant developments of commercially superior clones or natural varieties. Aromatherapy training schools and essential oil importers are years behind such developments. The names oil importers give are simply the norm in the trade and are not the actual botanical name of the plants used to produce the oil. It is common that even the large essential oil importers can not find out what variety of plants are being used in the country of origin. Bear in mind that the large customers for essential oils are not particularly interested in such matters. They mainly want to know "what is the chemical composition", "how much is it per tonne", "can you keep up regular supplies". For a long time there has been a total separation between commercial oil production and end users. The producers will often grow their crops to meet the needs of their major customers and these most certainly are not to be found in the aromatherapy trades.
Why has all this misinformation come about then ? The reasons are complex, but there are a number of reasons.
1. Aromatherapy has grown as an offshoot of the beauty therapy business, and we all know what that trade is like for inventing 'wonderful' properties for their products.
2. Because aromatherapy grew from the beauty business, most of the early practitioners trained in France. The tradition developed as with so many beauty products, that if it has a French name or you did your training in France, then everything is wonderful. No one bothered to check if the people doing the training really knew what they were talking about and that still applies to this day. An unfortunate aspect of the French connection was not to bother to investigate the historical uses of essential oils in British (or other countries) medical professions and their flavour and fragrance trades. It has only been in recent years that some people have woken up to the fact that there is a wealth of information from such sources.
3. Many of the people who have established their businesses supplying essential oils, or in aromatherapy training courses, have had little if any relevant training in the science of plants, essential oils, or medicine. Therefore they have had little option but to:
a) Trust their suppliers statements about the quality of their oils.
b) To pass on to their students everything they themselves have learnt verbatim, because they possess scant knowledge on how to check the accuracy of what they have been told.
4. People in the flavour, fragrance and cosmetics trades who are expert in the production and chemistry of essential oils, have until recently kept aromatherapy at arms length. Therefore they have played little part in training aromatherapy teachers. When such experts have taken an active role, it has often been the cosmetic, fragrance and essential oil chemists, rather than the many other experts available on olfaction, dermatology, microbiology, psychology, etc.
5. Hardly anyone in aromatherapy has been prepared to fund, or share funding, the large investment in time and money necessary to establish the truths or untruths underlying the products and services they provide. Instead the general trend has been 'let's get qualified and set up our own school or a new association'. So again they simply end up proliferating the mythology to a new generation of students.
The trend has been towards the 'leading lights' in aromatherapy training, establishing organisations, so that they can in effect validate their own courses. Organisations such as the A.O.C. (and all of their member organisations), as well as most of those not in the A.O.C. have little real expertise on the subjects on which they say they are 'setting standards'. These 'trade interests' then form associations to "establish standards" which the poor gullible public then assume are evidence of some kind of expert training. Such bodies once established, are then very affronted when people start to question the whole basis of their knowledge, education and validation systems.
The apparent success of these organisations in gaining recognition
from governmental and educational systems, has little to do with them providing
evidence of accurate training standards. We simply happen to have
a government that seems to think that trades can adequately regulate themselves,
such political dogma is extremely fault-ridden. Historically, time and
time again, many trades have had to be regulated by legislation in order
to protect the public from dishonest traders and poor standards of service.
It is extremely rare to find a trade association which puts the general
public before its business interests. So please always bear in mind
that the fundamental interests of trade associations are self protection.
A further problem with aromatherapy education is found in the therapeutic actions attributed to certain essential oils. Common examples are the so called 'diuretic' effects of fennel and juniper oils. In addition the ‘anti cellulite’ effects of grapefruit oil, (beauty therapy con trick!!!)
There is no evidence, that essential oils when applied to the skin in the amounts commonly used in massage, can be absorbed into the systemic circulation, in sufficient volume, to be able to cause any diuretic action. These claims originate from two main sources:
1) When these oils are given as internal medication they will stimulate & irritate the kidney thus causing the release of more urine.
2) The traditional use of water or alcohol herbal extracts which are also given internally.
On the other hand there is sound evidence, that diuresis can occur simply as the result of ordinary massage. Haemodilution following massage has been detected, which helps explain the common side effect following massage, of a quick trip to the toilet followed by thirst and the need to have a drink. Ordinary massage has been shown to produce a number of physiological effects on the body such as increase in ?-endorphins which play a part in pain relief. There are also indications that massage can cause alterations in hormone levels. Therefore it may be seen that many of the claims made by aromatherapy writers for their therapy, can in fact be explained by the effects of the massage, not by the effects of the essential oils used.
So why are aromatherapy books full of so called "researched" information on the use of essential oils which does not stand up to scrutiny? The answer is, that few writers, have had any education in the botanical and phytochemical sciences. Due to their weak knowledge of the subjects they write about, they do not have the ability to differentiate between the use of an aqueous herbal extract and an essential oil. Numerous examples can be found in popular aromatherapy books, of medicinal claims being made for an essential oil based on information gleaned from old herbals. Such herbal information being mainly on the internal use of water or alcoholic extracts. This type of extract contains hundreds of compounds which do not appear in the same plants essential oil. These water soluble compounds can exert profoundly different actions to the essential oil.
The next myth is that an essential oil represents "the life force" in the plant. This is complete and utter nonsense, how can any life force reside in a product that has been processed and cooked to the degree of an essential oil? If that were the case, how is it that we do not benefit from the "life force" present in the huge volumes of animal fats that are extensively consumed? Any life force which is inherent in plants is much more likely to be found in herbs or vegetables from the garden eaten raw. This question of life force being transferable to humans is no different in principal, to the old tribal beliefs, that you could inherit the power of an enemy by eating his brain. I hope we all know now what a load of nonsense that is.
It must be "organically grown". While I would always want to support
this method of production, there is little evidence that it makes any significant
difference to the properties of the essential oils yielded. In any
case since most parts of Europe have traces of agro-chemicals in the ground
water, or drift from agricultural spraying can travel for miles, is their
any such thing as agro-chemical free produce?
The oil is "field distilled". Any such crude methods of distillation, will generally not produce such a good oil, as one that has been produced under the controlled conditions of a modern processing plant. There are of course always exceptions to this general rule, for instance plants such as peppermint and rosemary, where carefully controlled local water and steam distillation is preferable to avoid the volatile 'top notes' escaping.
"It is not an essential oil unless it has been steam distilled". Such statements show a complete ignorance of the chemistry of plant extracts, as well as the plant extract processing trade. The best quality essential oils are cold processed. Steam distillation destroys or reduces many valuable components in essential oils. Certainly the highly volatile chemicals which play an important part in the therapeutic effects of freshly gathered herbs are substantially reduced by hot distillation. There are only a tiny number of oils which require hot distillation in order to produce naturally derived beneficial chemicals such as azulenes.
The perfumery and food flavouring trade are well aware that hot distillation damages delicate chemicals in aromatic extracts. Due to this they are increasingly turning to cold extracted essential oils, in particular carbon dioxide, or molecular extracts.
If the concept of "it must be steam distilled " is followed to the limits, then aromatherapists should not use: rose absolute (commonly sold as rose oil) and jasmin absolute. In addition, according to their own doctrine, they should not use the floral absolutes originally produced exclusively for the fragrance trade, but which aromatherapists are constantly requesting from their suppliers. A good quality rose absolute, because its fragrance is closer to the living flowers, will invariably produce a superior relaxing effect than an overheated-denatured steam distilled rose oil. Absolutes may stand a marginally higher chance of producing skin irritation than the equivalent steam distilled oil. However due to their price, most people can't afford to use them at levels that are likely to produce such a response.
So compare what is written here, on which sound evidence exists, with what is said in aromatherapy books, on courses and in the verbal or printed literature from some essential oil suppliers.
?. M. Watt 1994. Revised Oct. 1996.
© 1996 Martin Watt.
Martin can be reached at:
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