The essential oils that are traditionally or anecdotally associated with weak estrogenic effects include clary sage, sage, fennel and anise oils. The seeds of Black Cumin were used to plump out women’s breasts in Egyptian times but there is no information on whether the essential oil of Black Cumin has similar properties. Any estrogenic activity of lavender and tea tree oils is not supported in the literature by historical or anecdotal observations.
‘A sensationalised assumption’
Christopher Dean, Chairman of the Australian Tea Tree Oil Industry Technical and Safety committee, after consultation with numerous research scientists, described the report as having ‘ very little substance, … a product of poor reasoning and is cast into doubt on many grounds. Many researchers and scientists have looked at this article and raised concerns and alarm at the poor methodology and conclusions. There is no good science to link this to tea tree oil while there are dozens of other plausible hypotheses that are not even considered.‘
As Dr Porter is keen to point out:
“The authors of the paper admit the assumption that it was the essential oils that caused the problem, and that none of the other components of any of the products used on the children were tested for their effect(s). Nor was there anything to show that the oils used in the in vitro tests were the same or even similar to those used in the products.”
Henley, in his report, cautioned patients of prepubertal gynecomastia to avoid repeat exposure to these essential oils, but in a phone interview he said there is not nearly enough evidence to indicate that people should stop using products with lavender oil or tea tree oil, even young boys.
To Summarise:
“This publication is, to say the least, unscientific. The conclusion stated in the summary is not supported by the cell culture studies. The authors show no curiosity at all about the enormous difficulties in attempting to connect the cell culture studies with the case studies scientifically. It is disappointing to see the New England Journal Of Medicine publishing such work uncritically, allowing such material to damage its own reputation and to create unwarranted alarm and commercial damage around the world. A retraction is warranted.”
Australian Tea Tree Industry Association report.
As a tea tree oil producer I can only speak with some authority about Melaleuca alternifolia oil. I must leave the defence of the lavender case to the NZ lavender industry except to say that lavender oil has been widely used for thousands of years in natural hair and skin products with apparently no reported concerns.
Tea tree oil has been used for decades as a traditional and effective antiseptic with no adverse effects and is commonly found in natural shampoos, soaps and skin care products. It is widely available and has been investigated as an alternative antimicrobial, anti-inflammatory and anti-cancer agent. Anecdotal evidence from almost 80 years of use suggests that the topical use of the oil is relatively safe, and that adverse events are minor, self-limiting and occasional.
Obviously, those in a high-risk group with a clinical diagnosis of contact allergy should be careful when using botanical products, particularly concentrated extracts like essential oils but if people practise normal precautions when applying any essential oil, they can protect themselves from the possibility of an adverse reaction.
The main precautions are: avoid ingestion of undiluted oil; apply only diluted oil topically, except in certain ‘minor emergency’ situations; only use oil that has been stored away from exposure to light, heat and/or air; limit use of tea tree oil if you are pregnant or breastfeeding; keep tea tree oil out of the reach of children and pets.
Patch testing should always be done before applying any new oil. This is done by putting a few drops on the back of your wrist, cover with a plaster and leave for one hour. If irritation or redness occurs, bathe with cold water.
Adverse Reactions and Acceptable Risk
Those who use alternative natural health treatments and substances choose to take what they consider is an acceptable risk. Mainstream pharmaceutical products do not have an unblemished record and adverse reactions to drugs are very common in everyday medical practice. About 15 per cent of the population report adverse reactions to medication, but only five per cent are truly allergic reactions. The main drugs implicated are antibiotics and non-steroidal anti-inflammatory drugs.
While lip service is paid to “protecting consumers”, the actual outcome can be a crackdown on natural health products, reducing freedom of choice, rather than intelligent legislation to reduce excess risk. Perhaps it would be better to start by exactly characterizing the risk. How big is it? How many people have died or suffered other severe consequences? How many people are using the substance and are there reported positive effects? What is the balance between positive and negative? Is any intervention necessary? Let us hope that our future continues to include a healthy variety of options.
Article printed in Organic NZ magazine, May 2007 issue