A new paper by Hawkins et al. in the International Journal of Paediatrics & Adolescent Medicine has concluded that there is no such association between tea tree and lavender oils and endocrine disorders
This was based on a large prospective epidemiological study by the Franklin Health Research Centre in the US, with a cohort of 556 children, aged two to 15, giving a 95% confidence interval of 2%.
‘Prevalence of endocrine disorders among children exposed to lavender essential oil and tea tree essential oils’ looked at the causal links previous studies purported to find between these oils and breast development in young boys, a medical condition called gynecomastia, also known as premature thelarche in young girls. This began with a paper by Henley et al. in 2007.
Previous papers had challenged the links due to limited data, potential contamination of experimentation methods, or using products which did not contain either essential oil, but these did not have enough epidemiological evidence to refute these claims. As a result, sensationalist headlines remained and were widely publicised.
“This study provides evidence that lavender essential oil and tea tree essential oil are safe ingredients in formulations for personal care products used on children,” the authors concluded. “The proposed links between these ingredients and endocrine disruption cannot be substantiated in epidemiological studies.”
