By Julie Edgar, excerpted from WebMD:
Sept. 6, 2016 -- Tea tree and lavender essential oils are popular ingredients in personal care and household products, including many aimed at children.
But can the ingredients, often promoted as “natural” alternatives, trigger abnormal breast growth in boys and girls?
A few small studies suggest that frequently using lotions, shampoos, styling gels, and even a certain cologne containing lavender and tea tree oils may cause breast growth in boys, also known as gynecomastia, along with breast growth in girls as young as 4 or 5.
Other studies have not reached the same conclusions, and the cases appear to be rare. In addition, scientific research into most natural products is scant. The FDA doesn’t oversee essential oils unless they are intended for use in a drug, making it challenging to know how safe and effective these products are.
We asked a few experts to shed light on the research.
What the Studies Say
Lavender and tea tree oils are among the most commonly used essential oils used. Although research is inconclusive, lavender is often used for aromatherapy and calming lotions, while tea tree oil is promoted for acne, nail fungus, and other skin conditions.
In 2007, pediatrician Clifford Bloch, MD, noticed that three of his patients, boys ages 4, 7 and 10, had abnormal breast growth. After talking with their parents, he learned that one had been exposed to a lavender-based “healing” balm, another to a hair styling gel and shampoo with lavender and tea tree oil, and another to a shampoo and skin lotion with lavender.
Bloch ran tests looking for internal and external sources of the hormone estrogen that could potentially cause this to happen in the boys. He finally arrived at the cosmetic products the boys were using.
Lavender and tea tree oil have phytoestrogens, substances that mimic the hormone estrogen. Soy is a source of phytoestrogens, too.
Bloch’s findings, published in the New England Journal of Medicine, led to a 2007 National Institute of Environmental Health Sciences (NIEHS) study that found both oils can act like estrogen. The study prompted the National Institutes of Health to issue an alert about lavender and tea tree oils potentially acting as endocrine disruptors -- something that interferes with the endocrine system -- in boys who regularly used products containing them...