Essential oils linked to abnormal breast development in boys

By Dr. Ananya Mandal, MDMar 19 2018

A new study has found that essential oils such as lavender and tea tree oils are connected to development of abnormal breast development in young boys. They researchers found eight different chemicals present in these oils that can interfere with hormonal development in boys. The study results are to be presented today (19th of March 2018) at ENDO 2018, the Endocrine Society's 100th annual meeting in Chicago.

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Breast development in males is termed as gynaecomastia and this is a condition which has been associated with certain disease conditions and also as a side effect of certain drugs or medications. In many there may be no cause. In general gynecomastia is a rare condition.

The American study now has found that chemicals present in the essential oils can help increase the estrogen or female hormones in the boys and suppress the testosterone or male hormone. This reaction of course is different in different persons.

People use these essential oils directly as well as in daily use products such as lotions, moisturizers, creams, soaps, shampoos, hair styling products etc. Some of these are also used as part of alternative medical procedures. According to J. Tyler Ramsey from the National Institute of Environmental Health Sciences (NIEHS), in North Carolina, who led this new research, use of these oils in any form needs to be with caution among boys. He called these oils “endocrine disruptors” or agents that can alter the hormonal make up and create problems. He said that most of these oils are generally perceived to be safe. He said that there were quite a few reported cases of male gynecomastia after these oils were used over the skin. The symptoms came down once the oils were stopped.

Dr Kenneth Korach, a co-author in this study, has shown in his earlier work that lavender and tea tree oils can affect male characteristics development and puberty and growth among males. This new study looked at the chemicals within these oils. They narrowed it down to eight chemicals out of the hundreds present in these oils. Four of these chemicals are present in both oils. These four are eucalyptol, 4-terpineol, dipentene/limonene and alpha-terpineol. The other four including linalyl acetate, linalool, alpha-terpinene and gamma-terpinene, were in either of the oils.

The team then isolated the chemicals and tested them on human cells within the laboratories. They noted that these chemicals successfully increased estrogen levels and reduced testosterone levels in varying degrees. Ramsey said, these two oils need further study. These eight chemicals are also found in 65 other essential oils he said. These too need thorough investigation before boys are exposed to them.

The U.S. Food and Drug Administration (FDA) approves of the labels on essential oils as GRAS (generally recognized as safe) with usage as directed. This new study from the NIEHS shows that their use maybe with caution especially among pre-pubescent boys.