To continue our series of breaking EO myths (click here for Part 1: Cats & EO's and here for Part 2: EO's & Pregnancy), we definitely need to address the claims that essential oils like lavender and tea tree are estrogenic.
All of these claims can be traced back to a single study on THREE boys. The study stated:
“ In all three boys, gynecomastia coincided with the topical application of products that contained lavender and tea tree oils. Gynecomastia resolved in each patient shortly after the use of products containing these oils was discontinued.”
There are many problems with basing a world of claims that tea tree and lavender essential oils are estrogenic off of that study, such as:
1. It was hardly a thorough study with three participants.
2. The biggest problem--additional ingredients in the products used were not detailed. It is common for almost all body care products to include proven hormone-disrupting ingredients such as parabens and pthalates. (For those who want science: Read this full Endocrine-Disrupting Chemicals: An Endocrine Society Scientific Statement for info on known common hormone-disrupting chemicals in body care products.)
The products weren’t analyzed for the presence of other potential hormone disruptors, and the oils weren’t checked for purity. After developing their hypothesis, the researchers decided to test lavender and tea tree oil with human cells in a petri dish (in vivo). The results showed estrogenic activity which can be attributed to the solvent they used to dilute the oils – dimethyl sulfoxide – a known estrogen mimicker.
This reminds me of a study I read a long time ago (and lost the link to unfortunately but I'll never forget it because it was ridiculous). This study analyzed someone with high liver enzymes who drank soda daily, took milk thistle, and took acetaminophen. All three things were eliminated and liver enzymes improved. The study concluded that milk thistle increases liver enzymes.
Seriously.
Researchers and doctors weighed in on this:
“The study by Henley et al. raises many questions. Product names were not provided. Did the authors contact manufacturers to report concerns or ask about constituents? The variability, adulteration, and contamination of herbal products have been widely reported, as have discrepancies between labels and contents. Plastic containers may contain phthalates, known endocrine disrupters. What was actually in the products cited in this report?
None of the hormonal testing showed abnormal results, except in Patient 2, who had elevated levels of testosterone (not estrogen). There was no report on ultrasound examination or needle biopsy, nor were subsequent weight changes reported. ”
If we are going to base widespread claims off of research, we should have something a little bit more to base it off of. Let's look at some real research.
A 2013 study conducted in vivo (live, not in a petri dish) research on whether or not lavender is estrogenic. The study concluded:
“Based on these data, lavender oil, at dosages of 20 or 100 mg/kg, was not active in the rat uterotrophic assay and gave no evidence of estrogenic activity.”
http://journals.sagepub.com/doi/abs/10.1177/1091581812472209
NO ESTROGENIC ACTIVITY.
It's time to put this to rest.
What about fennel?
If you've heard that fennel is estrogenic and shouldn't be used during pregnancy for that reason, click here for Part 2 of this series: Pregnancy & EO's for information on fennel and estrogen.
Hope that helps in your journey towards good health!
Blessings,
Sara Jo Poff
Natural Health Practitioner