November 2016 Health Bulletin

There is increasing interest in chemicals called "endocrine disrupting chemicals"

These are chemicals which may be natural or synthetic, that through exposure interfere with an organisms normal hormone balance. The actions of these chemicals are complex. Some have weak hormone-like (endocrine-like) actions and others interfere with the pathways through which our hormones normally work, hence the term "disrupters". Endocrine disrupter chemicals include chemicals such as DDT and other pesticides, and plasticisers, such as bisphenol A (BPA) as well as phthalates and parabens.

The Endocrine Society guideline on this issue in 2009 stated that "The evidence for adverse reproductive outcomes (infertility, cancers, malformations) from exposure to endocrine disrupting chemicals is strong, and there is mounting evidence for effects on other endocrine systems, including thyroid, neuroendocrine, obesity and metabolism, and insulin and glucose homeostasis."

The Endocrine Society's Second Scientific Statement on Endocrine-Disrupting Chemicals, 2015, recognises this to be an international problem and that more public awareness as to how to minimise personal exposure, plus more research in this area is needed.

We are mainly exposed to BPA through food contamination including the inner coating of food cans and polycarbonate storage containers, tableware and water bottles. Therefore there is increasing interest in the effects of reducing BPA exposure. This includes not only exposure through foods but also through cosmetics and personal hygiene products packaged in plastics.

A recent pilot study looked at reducing BPA exposure. In the study of 24 women, half were randomly allocated to 3 weeks of reduced BPA exposure and half to no intervention (J Womens Health, 2016 Oct 11. [Epub ahead of print]). The reduced exposure group had a weekly face-to-face meeting and were given BPA-free cosmetics, hygiene, glass food/water containers, and daily self-monitored major sources of BPA. The intervention group had a significant reduction in the amount of BPA in their urine over the 3 weeks. This study provides evidence that BPA exposure can be reduced and provides a model for further studying the effects of BPA reduction in humans, such as on obesity.

Meanwhile, there are ways to reduce BPA exposure. These include using glass storage containers and reducing the consumption of canned food and drinks in plastic bottles that are not BPA free.

Other endocrine disrupters of interest include phthalates and parabens. Parabens are used as preservatives, notably in personal care products and some of these have extremely weak estrogenic activity. Phthalates are also used in personal care products such as perfume, cosmetics, moisturiser, nail polish, liquid soaps, and hair spray and have been implicated as endocrine disrupters. Researchers are investigating the role of these chemicals in conditions ranging from obesity and cancer through to endometriosis. While this research is ongoing, exposure to parabens and phthalates can be achieved by using paraben and phthalate free personal care products.

Information provided might not be relevant to a particular person's circumstances and should always be discussed with that person's own healthcare provider.