A commercial once said that Red Bull can give you wings (although a lawsuit argued that this is not actually the case). Can essential oils like lavender and tea tree oil give you breasts? Or rather bigger breasts, if you are male? At ENDO 2018, the Endocrine Society’s 100th annual meeting in Chicago, researchers from the National Institute of Environmental Health Sciences (NIEHS) will be presenting additional evidence that lavender and tea tree oil may give you more than just good feelings. The research team (J. Tyler Ramsey, B.S., Yin Li, PhD, Yukitomo Arao, PhD, and Kenneth Korach, Ph.D.) took four chemicals that appear in both lavender and tea tree oils (eucalyptol, 4-terpineol, dipentene/limonene and alpha-terpineol) and 4 that appear in either oil (linalyl acetate, linalool, alpha-terpinene and gamma-terpinene), applied them to human cancer cells in test tubes, and measured how they affected sex hormone activity. Of note, according to Ramsey, these chemicals are not specific to lavender and tree tea oils and appear in 65 other types of essential oils as well. The research team found that these chemicals may act like estrogens and block androgens like testosterone in ways that could give boys bigger breasts. If you’ve kept abreast with the science, you’ll realise that this is not the first piece of evidence that essential oils could lead to gynecomastia (the enlargement of male breast tissue) in boys before they reach puberty. In a study published in the New England Journal of Medicine in 2007, a research team that included Korach as well as other researchers from NIEHS (Derek V. Henley, Ph.D. and Korach) and the University of Colorado (Natasha Lipson, M.D. and Clifford A. Bloch, M.D.) applied lavender and tea tree oils to human breast-cancer (MCF-7) cells and showed how they changed various processes that affect oestrogen and androgen activity. They also reported on 3 otherwise healthy pre-pubertal boys, who had normal blood levels of oestrogens and androgens but developed larger breasts after using products that contained lavender or tea tree oils. Soon after the 3 boys discontinued using these products, their gynecomastia went away. Additionally, a publication in the Journal of Pediatric Endocrinology and Metabolism included case reports of 3 more boys who had prepubertal gynecomastia and had been exposed to lavender oil for long periods of time, with cologne being the source for 2 of these boys. (Presumably, people around the boys used the cologne and not the boys themselves.) This may be alarming to males who don’t like breasts in that way. But even if you for some reason want larger breasts, this does not mean that you should start smearing lavender and tea tree oil on yourself. Messing with sex hormone activity is potentially risky and may result in other effects beyond potentially giving pre-pubertal males larger breasts. Such sex hormones affect a wide range of body and cellular development, functioning, and characteristics in both males and females across different ages. Disrupting sex hormone activity could affect body growth and cancer risk. Of course, the studies to date do not yet definitively prove that lavender or tree tea oils will mess with your sex hormones. However, they do suggest that it is essential to conduct more scientific studies of such essential oils. Essential oils are not called essential because you “gotta have ’em”. Rather, these oils are compounds that apparently give plants their smell and flavour, otherwise referred to as their “essence.” (Which is a reason why you may want to avoid a product that says “essence of armpit.”) Essential oils are the mainstays of aromatherapy and seem to be appearing more and more in perfumes, other fragrances, food, and medicines. There are a lot of claims out there about the benefits of essential oils, some of which are supported by science but many of which are essentially pretty oily. PubMed Health includes a nice summary of the current scientific evidence on aromatherapy and essential oils. For example, it does say that “studies of aromatherapy massage or inhalation have had mixed results. There have been some reports of improved mood, anxiety, sleep, nausea, and pain. Other studies reported that aromatherapy showed no change in symptoms.” The argument for the use of essential oils is that they are extracted and distilled from plants, which are natural. But natural doesn’t necessarily mean useful or safe. A yak may be natural. But in your bathtub while you are showering, a yak is neither useful nor safe. Poison ivy and poison sumac are two more examples of natural things that are not necessarily good or safe. This is not to say that essential oils are the same as a yak in a bathtub. The U.S. Food and Drug Administration (FDA) does recognise and label many essential oils as GRAS (generally recognised as safe), when used as directed. This last qualification is important because all bets are off if you start using essential oils as ketchup. However, keep in mind that the FDA does not regulate the essential oil market as closely as it does medications. Testing of essential oils has not been nearly as extensive. As the NIEHS studies have shown, the science of essential oils is still emerging. We still do not completely know what essential oil products are doing to us and our environment. Moreover, not everything sold or marketed as essential oils is simply pure extract from plants. They may have undergone a lot of processing and been mixed with additional ingredients that could have essentially changed the essential oils. When you use a product, ask yourself do you really know what kind of gunk (which is a scientific term for “other stuff”) may have been added? As Yoda once said, “much to learn, you still have.” Yoda may have used a light-saber instead of lavender oil, but his quote captures the fact that there needs to be more scientific evaluation of essential oils before we know what they are actually doing to us. That sense of calmness when surrounded by lavender oil may not be the only thing growing in your chest.
Forbes, 18 March 2018 ; https://www.forbes.com