NIH Scientists Find Eight Chemicals In Essential Oils That ‘Make Boys Grow Breasts’

Lavender and tea tree oil had chemicals that showed anti-androgenic activity on human cells. Researchers found as many as 65 other essential oils have these chemicals.

Lavender Tea Tree Oil
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Lavender and tea tree oil had chemicals that showed anti-androgenic activity on human cells. Researchers found as many as 65 other essential oils have these chemicals.

Adding to a growing body of evidence for the hormone disruption effect of essential oils, a new study claims to have identified eight chemicals that make boys develop breasts.

Tea tree and lavender oil have been suspects for a long time in reports describing boys growing breast tissue, but until recently, a composition analysis identifying chemicals responsible in these oils was not reported. A group of scientists and clinicians, that had earlier observed male breast development in young boys, now claims to have found compounds that contribute to estrogenic and anti-androgenic properties of essential oils, BBC News reported.

Study lead investigator J. Tyler Ramsey, from the National Institute of Environmental Health Sciences (NIEHS), called for caution while using essential oils.

“Our society deems essential oils as safe. However, they possess a diverse amount of chemicals and should be used with caution because some of these chemicals are potential endocrine disruptors.”

More than a decade ago, pediatricians in Colorado observed prepubescent boys as young as 4-years-old showing symptoms of gynecomastia or breast enlargement. According to BBC, essential oils became suspect after doctors ruled out everything else.

The boys’ parents told doctors the children used shampoos, soaps, lotions, and gels with tea tree or lavender oil. When the children stopped using these products, gynecomastia symptoms subsided in months. Kenneth Korach, a scientist who co-authored the current study with Ramsey, had then run tests in the lab only to find that lavender and tea tree oil could mimic effects of female hormones on human cells.

Gynecomastia in prepubescent boys is rare as it is known to be a disorder of the middle-aged and elderly men. Dipping levels of testosterone, with aging, is believed to be one of the contributing factors for male breast tissue development.

Though its treatment in older men is purely for cosmetic purposes, in prepubescent boys it can be worrying as the underlying problem can affect growth and development.

Taking Korach’s observations ahead, Ramsey and other NIEHS researchers screened several chemicals in essential oils before they zeroed on eight chemicals which showed anti-androgenic and estrogenic activity on human cells. Of these eight chemicals, four chemicals – eucalyptol, 4-terpineol, dipentene/limonene, and alpha-terpineol, were found in both oils.

The other four found in either oil include linalyl acetate, linalool, alpha-terpinene, and gamma-terpinene. Calling for more research, the researchers expressed concern that as many as 65 other essential oils had similar chemicals they had tested.