the aromaconnection blog

Notes and News February 28

• Parrot's Oratory Stuns Scientists (BBC)  This light-hearted story has an olfactory connection in that N'kisi the parrot seems to know and communicate somewhat intelligently about aromatherapy.
• The Centers for Disease Control and Prevention has published a report this month which quotes alarming statistics from the National Vital Statistic System indicating that nearly all poisoning deaths in the United States are attributed to drugs, rising 62.5% during the 5-year period of study, 1999-2004.  The study includes both prescription and illegal drugs and ranks these types of poisoning deaths second only to motor-vehicle crashes.  Other substances, including alcohol, unspecified chemicals and organic solvents rate way down the list with only an appreciable increase of 1.3%.   This is certainly more alarming than the lavender/tea tree/gynecomastia frenzy that spread throughout the media like wildfire.  We've previously posted two excellent industry papers debunking the original research published by the NEJM here and here. 
• Another somewhat related article in Scientific American helps us understand that scientific research can be flawed, with some suggestions for improvement.  One of the primary reasons, the article states, "is a lack of coordination by researchers and biases such as tending to only publish results that mesh with what they expected or hoped to find."  In the lavender/tea tree/gynecomastia controversy, certainly involving essential oil experts in the study would have presented a different outcome.

Ethanol Risk (?)

An interesting situation blew up regarding ethanol toxicity for the EU cosmetic regulators, where seemingly the imposition of their own health & safety policies could have threatened the stability of the very industry they were regulating. Of course the regulators could contrive to bend the rules – but if they did bend them for ethanol, then why not also bend them for other important natural products that have inconvenient toxicological properties?

The development of high-art perfumery in Europe is of course linked to the use of aqueous ethanol (alcohol), where it acts as both a solvent and reactant for the constituent ingredients i.e. in a sense, the odour profile of a matured ethanolic fragrance can be considered greater than the sum of its individual odourants as a number of chemical changes and equilibria are set up over a short period between reactants and their stable/quasi-stable products. The addition of aqueous alcohol to ‘perfume compounds’ (the term for a perfume formulation minus the ethanol or other carrier) is a therefore a process which traditionally has required a little ‘know-how’ to obtain optimal results.

The preparation of natural aromatic ingredients (such as absolutes, tinctures & ingredient dilutions) is also linked to ethanol use. Whereas modern methods of preparation of absolutes invariably gives ingredients with very low percentages of residual ethanol, the use of tinctures (ethanol extracted/matured solutions of aromatic raw materials) would be more directly affected. However moderate corporate perfumery rarely incorporates the use of tinctures nowadays – it is part of a lost art – but this is not necessarily so in natural perfumery.

The French independent occupational safety group, the National Institut de Recherche et de Securite, had submitted a proposal in 2006 (their motivation is unknown to me) to classify ethanol as a category 1 CMR (Carcinogenic, Mutagenic or Reproductive toxin - see EC Directive 67/548) substance under EC Directive 67/548/EEC – a Directive which relates to the classification, packaging and labeling of dangerous substances. Up to that point, and under the 7th Amendment to the Cosmetics Act 76/768/EEC, if successful this categorization move would have required the European Commission to ban ethanol in cosmetics (and therefore perfumery). Additionally the European Chemicals Bureau had on its agenda for Oct 7th, a proposal to classify ethanol as a CMR material:

COLIPA had also submitted an opinion pointing out the socio-economic implications of this ban, which would require the banning of perfumes, after-shaves, colognes, eau de toilettes, some mouthwashes etc etc. and points out that this move if enacted would require many workers to wear gloves & respirators to avoid contact with ethanol i.e. when working in bakeries (ethanol is produced by panary fermentation in bread dough), in hospital labs, in bars etc. etc.

EFFA had argued that effective risk management is already in place for ethanol and only direct oral consumption is linked to adverse health effects – therefore EFFA's reasoning is that objections under the labeling directive 67/548/EEC do not address the problem (i.e. the problem is seen as purely that of oral intake).

Nevertheless up to that point, under the proposed classification for ethanol under National Institut de Recherche et de Securite proposals would seem to be:

F (R11: highly flammable) - this is unchanged, but additionally:

T Mutagenic Cat 2 (R46: May cause heritable genetic damage)
T Carcinogenic Cat 1 or 2 (R45: May cause cancer)
T Reproductive Toxin Cat 1 (R60: May impair fertility)
T Reproductive Toxin Cat 1 (R61: May cause harm to the unborn child)
R64: May cause harm to breast-fed babies

So the proposed labeling would be:

Symbols T; Xi; F
The Risk Phrases would be R11-R36/37-R40-R46-R60/61/64
The Safety Phrases would be S1/2-S26-S45-S46-S53.

However more careful examination of the ECB website under meeting schedules 4-5th October in Arona, reveals that there is a section for documents under 5.2 ‘Classification of Existing substances not subject to Risk Assessment’, where we see the  entry for MOO5 Ethanol.  – “No in depth discussion foreseen on mutagenicity and reproductive toxicity”. So does the philosophy of the 3 Wise Monkeys (hear no evil, see no evil, speak no evil) apply here – if so don’t open the huge & horrendous  MSDS data file for ethanol ECBI/22/06 in the next column.

The update document  ECBI/22/06 Add. 1 by Jan Cepcek of the Centre for Chemical Substances & Preparations in the Slovak Republic might have the last word here, where Cepcek argues that it is appropriate to separate industrial ethanol from ethanol in alcoholic beverages. Which neatly hands the problem conveniently on, as one strictly pertaining to food safety.

So, a return of the days of prohibition, perhaps? Knowing the influence of big industry on the EU regulatory process, I very much doubt it….!

Tony Burfield

Juniper is disappearing in Britain

Juniper berries from Juniperus communis are the traditional flavouring for gin-making, being harvested by hand in late summer and collected in traditional wooden trugs in Tuscany & many parts of Eastern Europe. Although some slight fermentation occurs during gathering, too much will impart a turpentine-like note in the beverage. The terpeneless, sesquiterpeneless or re-rectified essential oil prepared from the berries is the ingredient used as a component of gin-making, & cheaper beverages rely almost exclusively on juniperberries to provide the flavour components. More exclusive gin brand names however include a large number of other flavouring components (several being essential oils, such as coriander, orange & cardamon) to give the characteristic brand taste.

The essential oil of juniper berries contains mainly hydrocarbons, especially alpha-pinene, the content of which can vary from 25-55%, some gin manufacturers preferring the alpha-pinene level to be over 50% mark. Small amounts of other monoterpene alcohols such as alpha-terpineol, nerol and geraniol, may also be important for odour quality, and characteristic berry notes might be provided by components such as junionone, juniper camphor and others. Interestingly, the urine of individuals taking juniperberries as a herbal diuretic (the essential oil having a diuretic effect) is said to smell of violets. Commercially juniperberry oil has often been adulterated with limonene and/or juniper twig oils; “berry oils” containing juniper twigs or even branches probably reveal an analysis profile that has increased levels of alpha-cedrene, thujopsene and alpha-cedrol.

A little goes a long way: the use of juniper oil in beverage flavourings is limited to 0.01% in practice due to the gastric irritation effect of juniper oil. Various studies have also revealed that kidney irritation from juniper oil has been ascribed to the terpinen-4-ol content (Schilcher H et al. 1993); & diuretic activity has also been ascribed to terpinen-4-ol which has been said to increase the renal glomerular filtration rate.

A newspaper story by Randall (2007) reports on a study by the plant conservation charity Plantlife, which suggests that the relatively slow-growing juniper, one of only three native conifers, is rapidly dying out in British hillsides. Numbers have shown a 50% decline since the 1970’s - and the species could disappear altogether if nothing is done. Diminishing demand for UK berries (most are now imported, or imported as crude juniperberry liquor), less demand for juniper as firewood and the prickly branches as fencing, and changing land management patterns, are blamed for the situation.

Juniper is becoming yet another example of the ‘use it or lose it’ phenomena amongst economically important plants. Planting juniper species in gardens as ornamentals might help to offset its continuing decline in the wild.

Tony Burfield

References.
Randall D. (2007) “Nations gin tree in need of a tonic” Independent on Sunday 18.02.07 p31. 

Schilcher H et al. (1993) PZ Wissenschaft 138(3-4), 85-91.

Posted for Tony by Blogmistress

Strange What Can Be Found on the Internet

Strange what can be found on the Internet. Here’s a little piece from a recent IFRA Newsletter. which quotes a piece from Claire Thévenin’s article “Strategic switch for IFRA” from the excellent trade magazine (in my value judgment)  Parfums Cosmétiques Actualités:. As you can read for yourselves, Thévenin alludes to an “ambitious communication campaign and research programs that IFRA has put in place and is implementing” and she refers to 5 five distinct communication targets: the media, the industry’s clients, legislators, NGOs and the association’s members.

However it is Jean-Pierre Houri’s alleged remarks (Houri is IFRA Director General) that are especially illuminating. Aside from pointing out that RIFM’s budget is now USD 8 million (that’s an awful lot of corporate subsidy, says Cropwatch, whose USD budget is zero!), Houri is quoted as saying “IFRA does not consider the general public as being a target for IFRA.” Houri further states  that  “the brands need to speak to their consumers while IFRA concentrates on journalists, and supplying them with information that will then passed on to the public.”

We have already seen how obedient industry journalists & editors (with some brave & notable exceptions) have reported IFRA’s version of events over the Cropwatch Boycott of the 40th IFRA Amendment, so the public relations strategy described above is presumably working well for them. However excluding the general public, as Houri describes above, or selling them IFRA’s precautionary-principled propaganda via journalists loyal to IFRA, is dangerous for democracy, as it effectively disengages & disenfranchises the public and removes the opportunity for direct debate. The general public are, after all, the end-users of the fragranced products, and these people as consumers have the right to make their own opinions and to be able to have a say in the cosmetics regulatory process. 

Tony Burfield

Posted for Tony by Blogmistress

ATTIA Demands retraction of Gynecomastia Paper

In a press release issued on February 21 ATTIA, the Australian Tea Tree Industry Association, called for a retraction of claims that tea tree oil may have contributed to the growth of breasts in prepubesent boys in the paper Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oil. (published: New England Journal of Medicine 365 (5) pp 480-485 D. V. Henley, Ph. D., Natasha Lipson, M. D., Kenneth S. Korach, Ph. D. and Clifford A. Bloch, M. D.)

In a hard-hitting critique of the paper, after consultation with numerous research scientists, Christopher Dean, chairman of their Technical and Safety Committee not only completely debunks the study, but raises the issue of media responsibility that many people have been concerned about. It appears that reporters interviewing the scientists about the paper were more interested in finding out things that would sell newpapers than in finding out factual information.

As we have previously reported in this blog, the original paper and the articles about it created a media sensation and spread rapidly throughout the world via print media and the Internet. Blogs and newspapers kept picking up the articles and reporting the information as fact, usually omitting mention of the author's ambivalence about their results. But you can bet it will be very difficult to refute the media reports, since it would take a concerted effort by many people to contact all the newspapers via letters to the editor and to leave comments on all the blogs that have carried the story (particularly since many of them don't even accept comments).

This press release and other information published by Robert Tisserand and others provide the information that is needed to refute the original media furor. But as experience with the mainstream media demonstrates, it may not be easy to get the media to pay any attention.  Even if they do issue a retraction it will be on page A18, noticed by few and ignored by the rest.

But that does not deter the folks at ATTIA, and it should not deter us. We should be writing letters to the Editor and posting comments on blogs. Point people to the links in this article while raising the question of whether the information as reported by the media was correct. Check Google News to find out where the articles are on line. Currently there are 421 hits for Lavender and Tea Tree, which seems to give the most consistent set of articles -- with only two pointing out that the articles are incorrect.

It seems unlikely that the NEJM would actually retract the article, since what the scientific process is all about is publishing information so that others can agree with it or refute it. But ATTIA believes that they should, concluding their press release:

This publication is, to say the least, unscientific. The conclusion stated in the summary is not supported by the cell culture studies. The authors show no curiosity at all about the enormous difficulties in attempting to connect the cell culture studies with the case studies scientifically. It is disappointing to see the New England Journal Of medicine publishing such work uncritically, allowing such material to damage its own reputation and to create unwarranted alarm and commercial damage around the world. A retraction is warranted.

Opposition to IFRA 40th Amendment Heats Up

Tony Burfield has an excellent and well-formed front page column on Basenotes expanding upon the IFRA situation.   He portrays a disdainful emerging "plantation mentality" when it comes to the lack of respect for individual perfumers themselves in the ever-expanding megacorp environment of the mainstream perfume industry and the aloof disconnect between those at the top and everyone beneath.  Such human rights recidivism may not quite move us back to the era of French colonialism in the early 1900's that brought us the insensitive representation of Africans in Vigne's Golli-Wogg perfume bottle (click on thumbnail) designed by Michel de Brunhoff in 1920, whose inspiration came from the books "The Adventures of Two Dutch Dolls  and a Golliwogg" and "The Golliwog in the African Jungle", by Florence Upton based upon her experiences with a rag doll that she played with as a child in New York.  Racism in perfumery at that time was also depicted in a glass Mandarin figurine bottle designed by C.K.Benda for Bryenne's Chu Chin Chow released in 1918, which presents a jaundiced Westernized view of a different culture, complete with a 'decapitated' version when the lid is removed.  In the 21st Century, most of us would find this blatant racism distasteful to the extreme.  So, now, in modern time, has classism replaced racism?  Or are they both alive and well and we're so saturated with consumerism that most of us have lost touch with reality?  The battles between human rights organizations and corporate conglomerates and intrusive governments are ubiquitous today; one can hardly fathom the rapidly changing and ever-expansive restrictive environments that drown out the voices of the people, especially because of the loss of an independent media.

The IFRA 40th Amendment controversy may seem to not carry the weight of more overwhelming issues such as AIDS and world hunger, hurricanes and floods, but it is another ka-ching in favor of big business stealing all the marbles and denying access to the game by the artisan perfumer and indie natural cosmetic products maker.

Justice Douglas once said, "Power only concedes power when demanded."  With globalization, the corporate power seems more ominous than ever.  So what, the population has grown also; there are more of us, too.  People, that is. Real folks who need to stop behaving like the automatons these corporations would like us to be.  In the weeks to come, we at Aromaconnection will put forth energy to gather action and momentum to support Cropwatch's huge (but no doubt sometimes lonely) efforts to speak truth to power for all of us.

Notes and News February 22

• A blog post entitled Aromatherapy and Affect on one of the ScienceBlogs takes a mixed view of aromatherapy. While citing several research items that show that aromatherapy is effective, they take a rather skeptical attitude towards marketing hype for products such as Smiley or the Lavender Bunny.
• Free Aromatherapy Workshop for Breast Cancer Patients, Survivors Tuesday, March 6, 7 pm to 8:30 pm at Adelphi University in Garden City, NY, registration required 516.877.4325
• Seems the lavender/tea tree gynecomastia misconnection is even inserting itself into mundane, but mostly harmless aromatherapy advise to the public.  Scroll down to the lavender section.
• Aromatherapy Science: Aromatherapy Research on the web -  database of use to aromatherapists.
• The Enfant Terrible of Contemporary Perfumery, Christophe Laudamiel, takes on educating your nose in public schools.  Great idea!
• Aromas of rosemary and lavender essential oils differenttially effect cognition and mood in healthy adults says study performed at the Human Cognitive Neuroscience Unit Division of Psychology, University of Northumbria, Newcastle.

Research Notes: Tea Tree Treatment for Acne

A research paper in the Indian Journal of Dermatology, Venereology and Leprology supports the efficacy of tea tree oil in treating acne.

Enshaieh S, Jooya A, Siadat AH, Iraji F. The efficacy of 5% topical tea tree oil gel in mild to moderate acne vulgaris: A randomized, double-blind placebo-controlled study. Indian J Dermatol Venereol Leprol [serial online] 2007 [cited 2007 Feb 20];73:22-25. Available from: http://www.ijdvl.com/article.asp?issn=0378-6323;year=2007;volume=73;issue=1;spage=22;epage=25;aulast=Enshaieh

Abstract

Background: Finding an effective treatment for acne that is well tolerated by the patients is a challenge. One study has suggested the efficacy of tea tree oil in treatment of the acne vulgaris. Aim: To determine the efficacy of tea tree oil in mild to moderate acne vulgaris. Methods: This was a randomized double-blind clinical trial performed in 60 patients with mild to moderate acne vulgaris. They were randomly divided into two groups and were treated with tea tree oil gel (n=30) or placebo (n=30). They were followed every 15 days for a period of 45 days. Response to treatment was evaluated by the total acne lesions counting (TLC) and acne severity index (ASI). The data was analyzed statistically using t-test and by SPSS program. Results: There were no significant differences regarding demographic characteristics between the two groups. There was a significant difference between tea tree oil gel and placebo in the improvement of the TLC and also regarding improvement of the ASI. In terms of TLC and ASI, tea tree oil gel was 3.55 times and 5.75 times more effective than placebo respectively. Side-effects with both groups were relatively similar and tolerable. Conclusion: Topical 5% tea tree oil is an effective treatment for mild to moderate acne vulgaris.

The paper is available online but the PDF version is only available to subscribers.

Also Noted:

From PubMed an abstract for another new paper in Psychiatry Res. 2007 Feb 6; [Epub ahead of print]

Smelling lavender and rosemary increases free radical scavenging activity and decreases cortisol level in saliva.

Notes and News February 21

• Aromatherapy tops the list of popular complimentary therapies in report from the University of Ulster which notes that the numbers of adverse events recorded were very low.
• Perfumer & Flavorist publishes a gracious response and apology for any part in creating the wedge between supporters of the Cropwatch petition regarding IFRA's 40th amendment and proponents of the amendment.  They include a letter from the Director General of IFRA which letter fails miserably if this was in any way an attempt to find common ground with the dissenters. The letter reeks of loaded and snooty terminology such as "so-called" and more or less comes off as being high-minded upholders of fairness and environmental stewardship, thus intimating that the opposers of the amendment are anything but.  Disappointing language that puts up a barrier to any real dialog among the parties and only reinforces the opinion of those out here crying "foul" on the amendment in the first place.  Why not proffer a direct letter to Cropwatch, Mr. Houri?

Lavender/Tea Tree Study Debunked

Neither lavender oil nor tea tree oil can be linked to breast growth in young boys

Robert Tisserand

Background

In a recent report, a correlation is alleged between commercial products containing lavender and tea tree oils and breast growth in young boys. Three cases were seen in boys aged 4-7, who had all been using such products. In each case, the breast growth reduced to normal parameters within several months of ceasing to use the products. Subsequent laboratory testing showed that both essential oils had estrogen-like properties (Henley et al 2007).

In the report, no information is given about any of the constituents of the products used. The information given about product use is sparse, and we do not know for certain whether any of the products contained lavender or tea tree oils, since they were not analyzed by the researchers.

The cases

Case one
In the first case, "The patient’s mother reported applying a "healing balm" containing lavender oil to his skin starting shortly before the initial presentation." No further details of the product or its use are given, but a healing balm sounds like something that might only be applied to a small area of skin. If so, then it is unlikely that any ingredient could have entered the boy’s blood in sufficient concentration to cause gynecomastia within a short time period.

Case two
In the second case, a styling hair gel was applied to the hair and scalp every morning, along with regular use of a shampoo. Both tea tree and lavender oil are cited on the ingredient list of both products.

In a subsequent website report, it is claimed that the two hair products used in this case were manufactured by Paul Mitchell, and that these were analyzed by a competitor. The shampoo was said to contain "very low concentrations" of tea tree oil, and the content in the hair gel was "virtually undetectable". Lavender oil concentration was not checked (Neustaedter 2007).

Dermal absorption of fragrance from shampoo application has been estimated to be 80 times less than that from body lotion (Cadby et al 2002). If the website report is genuine, considering that shampoo is a wash-off product, and that there was only a negligible amount of tea tree oil in the hair gel, tea tree oil can be ruled out as a possible cause of this boy’s gynecomastia. However, liberal use of a hair gel rich in lavender oil could result in moderate dermal absorption of lavender oil constituents (Cal 2006).

Case three
The third case involved "lavender-scented soap, and intermittent use of lavender-scented commercial skin lotions". This sounds as if there may not be very much natural lavender oil present. Further, soap is a wash-off product, and the use of lavender lotion is described as "intermittent". Whether any absorption of genuine lavender oil took place at all seems doubtful.

Since dermal absorption of soap fragrance is some 266 times less than that from body lotion, it is  virtually impossible that the fragrance in a soap could be absorbed in sufficient quantity to cause any physiological effect (Cadby et al 2002).

Of great interest is the statement that, in this third case, a fraternal twin used the same skin lotions, but not the soap, and did not develop gynecomastia. It would be reasonable to assume that, since the soap could not be responsible for the effect, and since the twin used the lotions without any problem, the gynecomastia in this third case must have been due to some cause other than essential oils.

The in vitro testing

The in vitro evidence shows weak but definite endocrine disrupting effects for both lavender and tea tree oils. The second case was the only one in which tea tree oil was involved. Tea tree oil was tested because it was deemed to be "chemically similar" to lavender oil. However, apart from the fact that both are essential oils, they have little in common chemically.

The composition of the essential oils tested is not given, nor is any other information about them, apart from the supplier. Since they do not appear to be organically grown, biocide content is a possibility.

Discussion

It is unusual in such reports not to name the products suspected as being responsible for the effects under discussion. In the circumstances, it is also curious that the labeled ingredients were not cited. It is even more surprising that no attempt was made to ascertain, retrospectively, whether any constituents of lavender or tea tree oil were detectable. If the products are not named, no one else can test them either.

Even assuming that one or both of the essential oils were present at some level, we do not know what quantities of essential oil constituents may have penetrated the skin, but we do know that transcutaneous absorption from fragrances takes some time. The amount that could find its way into the blood from a wash-off product such as a shampoo or soap is negligible, because the time of skin contact is so short. Skin absorption from tea tree and lavender oil constituents is measured in hours, not minutes, in and some instances even leave-on products result in minimal dermal penetration (Cal 2006, Reichling 2006).

The Henley et al report mentions that none of the boys had been exposed to any known endocrine disruptor, such as medications, oral contraceptives(!), marijuana or soy products. However, no mention is made of other known endocrine disruptors, such as organochlorine pesticides, PCBs, polychlorinated dioxins, alkyl phenols, pthalates and parabens (Darbre 2006). Both pesticides and phthalates have been found in essential oils, and both phthalates and parabens are commonly found in cosmetic products.

It is, therefore, entirely possible that other ingredients in the products caused the gynecomastia. Pesticides, PCBs and dioxins are found in the environment, often in food, and it is also possible that some local surge of environmental hormone disruptors caused these cases in Colorado.

No attempt was made to identify the constituent(s) responsible for the in vitro effect, but it is reasonable to expect that any hormonal action in an essential oil would be due to one or two constituents, or even contaminants. It is noteworthy that, while in vitro hormonal effects from essential oil constituents have been previously reported, these are generally very weak, and have been estimated as being at least 10,000 times less potent than 17β-estradiol (Howes et al 2002).

There is no evidence that the effect seen in vitro would take place in vivo, and much more research would be needed before any definite determinations could be made. Many estrogenic substances have previously been identified from plant sources, and very weak activity is typical of these phytoestrogens (Chadwick et al 2006, Howes et al 2002).

Conclusions

As the report states, breast growth in pre-pubertal boys is extremely uncommon, yet three cases are reported within a short period of time, and all in the same clinic. Considering that some 200 tonnes per annum are produced of both lavender and tea tree oil, that most of this goes into personal care products, and that very little of the evidence presented for these 3 cases is convincing, the press reports of caution are premature.

Even if one or more of these cases was linked to product use, any connection with either lavender or tea tree oil is unproven. Other known endocrine disrupting ingredients in the products could have played a role. Furthermore, we do not know what other factors, such as dietary or environmental, may have played a part.

The in vitro work reported by Henley et al (2007) does indicate a hormonal effect. However, this cannot be extrapolated to estimate actual human risk, especially without knowing more about the essential oil constituents causing the in vitro effects seen. No connection was established between the in vitro work and the three cases, and the case for tea tree oil having an effect on prepubertal gynecomastia is especially weak. Phytoestrogens generally have a very weak hormonal activity, and it is implausible that the amounts of essential oil that enter the body from product use would have a significant effect. Further research will hopefully clarify these issues.

References

Cadby PA, Troy WR, Vey MG 2002 Consumer exposure to fragrance ingredients: providing estimates for safety evaluation. Regulatory Toxicology & Pharmacology 36: 246-252

Cal K 2006 How does the type of vehicle influence the in vitro skin absorption and elimination kinetics of terpenes? Archives of Dermatological Research 297: 311-315

Chadwick LR, Pauli GF, Farnsworth NR 2006 The pharmacognosy of Humulus lupulus L. (hops) with an emphasis on estrogenic properties. Phytomedicine 13: 119-131

Darbre PD 2006 Environmental oestrogens, cosmetics and breast cancer. Best Practice & Research Clinical Endocrinology & Metabolism 20: 121-143

FMA 2007 http://www.fmafragrance.org/sub_pages/020107henleyresponse.pdf

Henley DV, Lipson N, Korach KS, Bloch CA 2007 Prebubertal gynecomastia linked to lavender and tea tree oils. New England Journal of Medicine 365(5): 479-485

Howes M-J R, Houghton P J, Barlow D J et al 2002 Assessment of estrogenic activity in some common essential oil constituents. Journal of Pharmacy & Pharmacology 54:1521–1528

Neustaedter R 2007 http://www.cureguide.com/Natural_Health_Newsletter/Lavender_Dangers/lavender_dangers.html

Reichling J, Landvatter U, Wagner H, Kostka KH, Schaefer UF 2006 In vitro studies on release and human skin permeation of Australian tea tree oil (TTO) from topical formulations. European Journal of Pharmaceutics & Biopharmaceutics 64: 222-228

Contact: Robert Tisserand

Email:[email protected]