the aromaconnection blog

Notes and News

• Organic Monitor reports that there is an increase in the acreage of organic citrus groves in Florida. They focus on juice, but this should lead to better availability of organic citrus oils. 
• The C.A.M. Report has resurrected the Lavender/Tea Tree Gynecomastia issue again, by reposting an old post from 2007 without updating it to include information about challenges to the original research. 
• In the same post the C.A.M. report mentioned (without citation) a report that in 2005 essential oils were linked to 7,282 reports to poison control centers. UPDATE: JR forwarded the citation in a comment. He reported on this in the C.A.M. Report here. The article cited was here. The original source (PDF) of the data was the 2005 report of the American Association of Poison Control Centers.
• A new blog on food and local agriculture has been added to our Agriculture Horticulture link roll: La Vida Locavore.  Worth checking out if you like food.

Aromatherapy May Make You Feel Good, But It Won't Make You Well

Or so says a study by researchers at the Ohio State University that is spreading rapidly throughout the Main Stream Media and the Internet and is being cited as proof that aromatherapy doesn't work. Although I found it first on a blog about the convergence of Mormon beliefs and science, a little searching revealed that it has been extensively reported on MSM web sites and the OSU Press Release describing the study has been widely reprinted (621 Google hits for the title above), the most significant of which is ScienceDaily.

The study, published online in the journal Psychoneuroendocrinology, looked for evidence that such aromas go beyond increasing pleasure and actually have a positive medical impact on a person’s health.  While a massive commercial industry has embraced this notion in recent decades, little, if any, scientific proof has been offered supporting the products’ health claims.

This could have as wide spread a circulation as the NEJM article on Gynecomastia which has been discussed extensively on this blog a year ago. And unfortunately, as happened in the prior situation, there will probably be very little coverage of any intelligent criticism or further discussion that we might have about the results of the study.

Most of the wider media coverage is based on the press release, and it's likely that very few persons will read the actual study, because of the exorbitant fee charged to download a copy. The aromaconnection blog has sprung for the cost and I have actually read the paper. I'll need a couple of days to digest it but we will definitely be commenting further on it. My initial evaluation is that the methodology is valid, but that a study that is limited to only two essential oils is not the same thing as "Aromatherapy", but of course over-generalizations have never been rare in the media world or the Internet.

The abstract/summary of the paper is:

Despite aromatherapy's popularity, efficacy data are scant, and potential mechanisms are controversial. This randomized controlled trial examined the psychological, autonomic, endocrine, and immune consequences of one purported relaxant odor (lavender), one stimulant odor (lemon), and a no-odor control (water), before and after a stressor (cold pressor); 56 healthy men and women were exposed to each of the odors during three separate visits. To assess the effects of expectancies, participants randomized to the “blind” condition were given no information about the odors they would smell; “primed” individuals were told what odors they would smell during the session, and what changes to expect. Experimenters were blind.

Self-report and unobtrusive mood measures provided robust evidence that lemon oil reliably enhances positive mood compared to water and lavender regardless of expectancies or previous use of aromatherapy. Moreover, norepinephrine levels following the cold pressor remained elevated when subjects smelled lemon, compared to water or lavender. DTH responses to Candida were larger following inhalation of water than lemon or lavender. Odors did not reliably alter IL-6 and IL-10 production, salivary cortisol, heart rate or blood pressure, skin barrier repair following tape stripping, or pain ratings following the cold pressor.

If you'd like to find the paper on the Internet, you can find it on ScienceDirect by entering the keyword Aromatherapy. Right now it is the first entry.

NEJM Gynecomastia Article now available for free

Just a note that the original article (February 2007) in the New England Journal of Medicine on Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oils is now available here for free online. Apparently NEJM locks things up for about a year before publishing them at no charge. I imagine we will see another spate of media interest.

 

Technorati Tags: Lavender and Tea Tree Oils

Knight Science Journalism Tracker » USA Today: Should we all worry over estrogen-mimicking pthalates, bisphenol A, etc? (A: looks like it)

This article summary of a USA Today article suggests that the tide of scientific opinion on pthalates is turning towards concern about their effects.  Long time readers of this blog will remember last February when there was an attempt to blame gynecomastia (enlarged breasts) on lavender and tea tree oil. At the time many of us wondered if perhaps some other ingredients of the materials or packaging might have caused the effects noted. I did a literature search on pthalates but could only conclude that there were lots of opinions on both sides of the issue. Eventually the gynecomastia question will need to be revisited to reach valid conclusions about whether essential oils or other factors were actually the causative.

Lavender-Tea Tree Oil-gynecomastia Response to NEJM Article

The New England Journal of Medicine has published (subscription or purchase required) (h/t Tony B) several Letters to the Editor in its June 14 issue regarding the paper "Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oils" originally published earlier this year and extensively covered in the world media and extensively blogged about on the aromaconnection blog. The four letters from six authors make a number of points, including the following pastiche (paraphrased unless in quotes) drawn from all the letters:

Product names were not reported, raising concerns about what was actually present. There was no examination of alternate processes that might have caused the gynecomastia. Traditional uses or these oils have not suggested estrogenic effects. In vitro testing alone is not adequate to indict products. The estrogenic effects reported indicate a very weak effect. The tea tree effects were not separated from the lavender and "There is no rational process that could allow the authors to conclude that tea tree caused the gynecomastia. . ." "the estrogenic activity . . . was dose dependant." The effects became positive at levels at least 600,000 times the level of the positive control. "Testing was far from comprehensive." "The study . . . does not support a causative link . . ." The study was uncontrolled with other agents possibly having a role. ". . . an average 20-kg child would had to have used 40 bottles of shampoo for each application. The claim of a causative link . . . appears to be misleading and unwarranted."

The authors were given the opportunity to reply and fell back on the usual excuses: we used the ingredients list on the bottle; we didn't know about/find other research; some of the critics sell the stuff and therefore are scoundrels; other variables that we ignored might have been a factor; yes, our findings should be interpreted carefully; yes, there should be more research.

Not surprisingly, the publishers of the some 22,700 articles on the original paper that show up on Google appear to have overlooked the new information and discussion. That is because the there was no press release to raise it from obscurity and the limited access of NEJM economics that require payment to read it.

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.

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:rtisserand@onepost.net

Lavender/Tea Tree/Gynecomastia

The quest continues to stem the tide of potential misinformation about lavenderand tea tree essential oils/gynecomastia continuing on the newswires and in the blogs.  This article in The Oakland Tribune, I believe, shows more urgency regarding synthetics, and let's hope the newswires pick it up as readily as the NEJM published findings on two fairly innocuous essential oils.   

Hundreds of researchers and scientists gathered at UCSF for a reproductive health conference to present papers and contemplate the increase of toxic environmental synthetics and their actions as endocrine disruptors 

Bisphenol-A and diethylstilbestrol are among the synthetic compounds or drugs found as culprits and being presented in papers.  Alarming, the diethystilbestrol (given to mothers in the 40s who were prone to miscarriage) tested safe for those taking it, but consequences revealed themselves in their children, especially girls.  Girls exposed in the womb saw particularly high rates of diseases such as fibroid tumors and endometriosis, leading causes of infertility and hysterectomies.  Other highlights in the Oakland Tribune piece are worth a look. 

Lavender and Tea Tree create Media Furor

The publication of a study in the New England Journal of Medicine [subscription required for the full paper] and a related article in the NIH News have led to a media frenzy about Lavender and Tea Tree oils.

A study published in this week’s issue of the New England Journal of Medicine suggests that repeated topical use of products containing lavender oil and/or tea tree oil may cause prepubertal gynecomastia, a rare condition resulting in enlarged breast tissue in boys prior to puberty, and for which a cause is seldom identified.

The story has been picked up by the news services and the article has gained widespread coverage and is being published in local papers.

This information has been around since the paper was first presented at a conference last summer, and Tony Burfield covered it thoroughly in Cropwatch Newletter #4. As he concludes:

So…. any estrogenic activity of tea tree & lavender oils is not much supported in the literature by historical or anecdotal observations (apart from some very loose association with lavender), and no active substances found in lavender & tea tree oils causing these alleged associations readily spring to mind. It will be interesting therefore to see if the findings of Henley & Reiter can be independently confirmed with pure essential oils 100% derived from the named botanical source, and a direct biological mechanism derived for the process. Further, since other common natural phytochemicals such as linoleic acid have also been suggested as weakly estrogenic agents, it will be interesting to see how widespread the causes of this medical phenomena might potentially be - we are aware for example of the use of the seeds of Black Cumin Nigella sativa L. to plump out women’s breasts in Egyptian times (Genders 1986), but we have no information on whether the essential oil of Black Cumin has similar properties

The study is also being discussed on the Blogs.  Abel Pharmboy at Terra Sigillata seems to like the study, but points out that:

the offending components of each oil are not investigated or mentioned by name. Lavender (Lavandula angustifolia or L. officinalis) and tea tree (Melaleuca alternafolia) are among the most highly investigated medicinal and fragrance plants because their monoterpene compounds largely smell good and have been linked with anti-anxiety (lavender) and anti-bacterial (tea tree) effects. Howes et al. surveyed the estrogenic activity of many essential oil constituents and found that some compounds were weak estrogen agonists while others antagonized estradiol.

Comments?

Blogmistress comments: NIEHS researcher and co-author of the study,  Ken Korach, PhD, covered his you-know-what: "Although we found an association between exposure to these essential oils and gynaecomastia, further research is needed to determine the prevalence of prepubertal gynaecomastia in boys using products containing lavender and tea tree oils."  Methinks the paucity of conclusive scientific evidence and flawed research should nip this in the bud.  However, probably not.   I've been watching Senator Henry Waxman's Oversight Committee, in which findings reveal political influence on scientists to water down their findings on climate change, along with disturbing revelations about the pressure on FDA scientists.  More about that as we move along.