A friend's son uses a shampoo with tea tree essential oil listed as one of the ingredients and he finds it very effective at maintaining healthy hair and scalp. But she was concerned over recent press that chemicals found in lavender and tea tree can act as hormone disrupters and "lend further evidence to a suspected link between abnormal breast growth in young boys (prepubertal gynecomastia) and regular exposure to lavender or tea tree oil" . (1)
The study was done by a a post baccalaureate research fellow J Tyler Ramsey B.S., at the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health and presented at ENDO 2018, the Endocrine Society’s 100th annual meeting in Chicago.
Although I have not read the poster and the data has not yet been released, it appears the study involved eight chemical components found in essential oils (not whole essential oils) and their effect in cell culture. The researchers applied the chemical to cancer cells and measured the change in estrogen receptor and androgen receptor target genes and transcriptional activities. The researchers stated that the chemicals found is essential oils behave like hormones in their effects on the cancer cell line.
And as you can imagine people are concerned that tea tree and lavender may be dangerous or harmful for young boys and others. Time Magazine recently published an article in response to this new finding: "Are Essential Oils Safe?" (2).
This worry is not new. In 2007 researchers raised concern over both tea tree and lavender essential oil in an article published in the New England Journal of Medicine: "Prepubertal gynecomastia linked to lavender and tea tree oils". (3) The study linked use of lavender and tea tree containing products to prepubertal gynecomastia in boys but the study did raise questions. (4, 5) A counter study with lavender however, showed that it caused no estrogenic activity and was more akin to using products dermally. (5)
Ramsey states “I personally cannot recommend the public to discontinue or cut back any usages of these oils,... (but) the public should consider these findings when deciding to use essential oils, as they do contain endocrine disrupting chemicals (EDCs) and there may be health risks and implications when using these oils.”
The Australian Tea Tree Industry Society (ATTIS) suggests serious questions should be asked. They point out that tea tree oil (Melaleuca alternafolia) is a well established natural compound steam distilled from the tea tree plant. It has been approved by the European Medicines Agency as a natural herbal medicine for specific applications and the subject of over 830 clinical papers supporting its broad potential for consumer products.
Tea tree oil (TTO), they remind, has undergone extensive recent safety testing and TTO has passed all necessary testing as required by the European Chemicals agency for it Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) initiative with no "red flags". TTO they state, has been deemed safe and well tolerated. (6)
The ATTIS argues that the results of the 2018 study have been sensationalized and asked why the researchers did not test whole essential oils in addition to chemical components? Were the components naturally or synthetically derived? They countered that most of the substances tested do not penetrate the skin/dermal barrier and enter the bloodstream. They also stated that terpene compounds are highly prevalent in orange and other citrus juices and asked if these substances are ingested as foodstuffs in everyday life one would surmise a greater incidence of gynecomastia in the developed world as a result, yet it remains rare. And lastly they added that many false positives result from phthalates, nonylphenols, and other chemicals in lab plastics. (6)
The National Association for Holistic Aromatherapy (NAHA) has designed a Tea Tree and Lavender Safe Usage page (see: https://naha.org/explore-aromatherapy/safety/gynecomastia-puberty/) and their position is that the oils are safe as used under NAHA's safety guidelines such as proper dilution. They offer resources for further exploration. (7) Further guidelines for the safe use of essential oils can be found on the Alliance of International Aromatherapy Website. (http://www.alliance-aromatherapists.org/aromatherapy-safety) (8)
Essential oils are highly concentrated substances and one should be sure that their oils are pure and authentic. When diluted and used properly essential oils have had a long history of safety. Certified professional aromatherapists are trained to used essential oils safely with their clients and turn to research and publications such as "Essential Oil Safety"by Tisserand and Young to ascertain possible contraindications for using essential oils with any given client.
Some essential oils are not indicated for use during pregnancy for example. Aromatherapist and their governing bodies monitor and evaluate research for safe use of essential oils.
For now it seems that the 2018 findings draw an association between chemicals in cell culture and hormone like activity while another study with lavender found no estrogenic effects. We have seen a good track record for safe use of lavender and tea tree essential oil and we have seen studies where lavender does not have estrogenic activity.
As an aromatherapist I will continue to examine the research on these oils and keep essential oil safety at the forefront.
For now I can present the findings to my friend and she will ultimately have to decide if she feels ok letting her son use tea tree containing shampoo. The National Association of Holistic Aromatherapists many aromatherapists, and aromatherapy researchers feel that when used properly essential oils are both safe and beneficial.
As an essential oil user it is important to stay informed and to seek advise from knowledgeable professionals who are well informed concerning essential oil chemistry, practice, and research.
If you wish to continue the conversation or have questions about this new research please feel free to contact me or visit one of these informative sites:
NAHA TEA TREE & LAVENDER SAFETY PAGE
Alliance of International Aromatherapists
To the safe, knowledgeable use of essential oils,
1. Endocrine Society, Lavender and Tea Tree Appear to be Hormone Disrupters, Accessed May 5, 2018, https://www.endocrine.org/news-room/2018/chemicals-in-lavender-and-tea-tree-oil-appear-to-be-hormone-disruptors
2. Time Magazine, Are Essential Oils Safe? Accesses May 5, 2018, http://time.com/5203122/are-essential-oils-safe/
3.N Engl J Med. 2007 Feb 1;356(5):479-85.Prepubertal gynecomastia linked to lavender and tea tree oils.Henley DV1, Lipson N, Korach KS, Bloch CA.
4. New England Journal of Medicine Letters to Editor, http://www.e-lactancia.org/media/papers/LavandaGinecomasia-2-NEJmed2007.pdf
5. Australian Tea Tree Industrial Association, 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.)
6.Int J Toxicol. 2013 Mar-Apr;32(2):123-9. doi: 10.1177/1091581812472209. Epub 2013 Jan 28.Uterotrophic assay of percutaneous lavender oil in immature female rats.Politano VT1, McGinty D, Lewis EM, Hoberman AM, Christian MS, Diener RM, Api AM
6. Australian Tea Tree Oil, ATTIA refutes New Gynecomastia links, Accesses May 5. 2018. http://www.teatree.org.au/read_more.php?id=620
7. NAHA Website, Explore lavender and tea tree, accessed May 5, 2018, https://naha.org/explore-aromatherapy/safety/gynecomastia-puberty/
8. Alliance of International Aromatherapists, Essential Oil Safety, Accesses May 5, 2018, http://www.alliance-aromatherapists.org/aromatherapy-safety