Gynecomastia in Young Boys?

Recently a new study was announced that claims that lavender essential oil causes breast swelling in young boys. There are several things that I take issue with concerning this new information.

Critique of the Study

  1. First, this study is NOT out yet; it is just an announcement of the study from the authors at a conference. Since the study isn’t out yet, I have no way to assess the dose. It is possible that the dose is massively larger than what humans use on a regular basis. This is exceptionally common in cell and animal research.
  2. The study used essential oil constituents, not a true essential oil. The study did NOT look at a complete oil, only extracts of eucalyptol, 4-terpineol, dipentene/limonene and alpha-terpineol, linalyl acetate, linalool, alpha-terpinene and gamma-terpinene. In my practical experience with oils, I have never applied a fraction by itself.
  3. The authors then applied the oil fractions to human cancer cells, NOT healthy cells. Interestingly, some of the authors from the 2007 NEJM article are also on this study. Both studies used cancer cells to test estrogenic activity. I have already posted on my blog that cell cultures are not the gold standard test for estrogenic activity. My guess is that this new article will take similar criticism to the 2007 article because they failed to include a uterotrophic assay as part of the study methods. Cancer cells, especially breast cancer cells used in the 2007 study, respond differently to estrogen than normal cells do. Therefore this is not an accurate presentation of the average human use.
  4. This panic that is going around was NOT prompted by any child actually getting gynecomastia. The authors of the new study state that the hormonal changes they observed were “consistent with endogenous, or bodily, hormonal conditions that stimulate gynecomastia in prepubescent boys”. But the fact still remains. . . no child actually suffered from gynecomastia. . . this is ALL theoretical evidence. Yes, there are some case reports of children acquiring breasts from lavender oil, but I am skeptical of this evidence too, and cover it here.

Bottom Line

From a practical standpoint, I still do not consider lavender oil of high risk for causing breast swelling in young boys. Additionally, I can vouch that it definitely does not work for grown women. While we may have some high profile case reports and articles, the overall number of children who acquire gynecomastia from products containing essential oils pales in comparison to the number of children who actually use essential oils.


To view my first post regarding this subject, click here.

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