What’s the fuss about... Parabens?

You may have noticed lately that "paraben-free" labels have been popping up on a range of cosmetics and beauty products.

Parabens are the most widely used preservatives in personal care products; they stop fungus, bacteria and other microbes from growing in your favourite creams and make-up, especially in the moist, warm environment of a bathroom. Their names are a mouthful – methylparaben, ethylparaben, propylparaben, butylparaben and isobutylparaben. You’ll find them listed on thousands of personal care products including shampoos, foundations, mascara and body lotions.

But over the past few years, a debate has been building among scientists, product safety regulators and cosmetics manufacturers about whether these ubiquitous chemicals, used for almost 70 years, may actually be harmful to our health.

Some of the questions being asked:

Is the rising incidence of breast cancer linked in part to the fact that parabens, which have a weak ability to mimic oestrogen, have been found in breast cancer tumours and can be isolated from other body tissues?

Are declining sperm counts and increasing rates of male breast cancer and testicular cancer related to the fact that these chemicals can be absorbed into our skin, potentially disrupting our endocrine systems?

The simple answer: we don’t know yet. But some researchers feel there may be reason for concern. One of the most vocal is Philippa Darbre, a senior lecturer in oncology and researcher in biomolecular sciences at the University of Reading in England. In 2004, Darbre’s team published a pivotal study that detected parabens in 18 of 20 samples of tissue from breast tumour biopsies.

Her study didn’t prove parabens cause cancer, only that they were easily detected among cancerous cells. The study was criticised for not comparing paraben levels in normal tissue, but nevertheless, the results called out for more investigation.

"We’ve known for more than 25 years that oestrogen exposure is linked to breast cancer development and progression; it is the reason tamoxifen (commonly prescribed to women with breast cancer) is used to disrupt oestrogen receptors," says Darbre. "So it is not such a leap to be concerned that repeated, cumulative, long-term exposure to chemicals that weakly mimic oestrogen might be having an impact."

Darbre is particularly worried about lotions and deodorants applied under the arms or near the breast, and hasn’t used underarm deodorant herself for ten years, opting instead to use just soap and water. She notes that research has found that roughly 55% of all breast cancer tumours occur in the upper outside portion of the breast, the section closest to the underarm. The US National Cancer Institute has partly dismissed the claim, maintaining there is no decisive evidence at present to conclude that the parabens are linked to breast cancer and that further research is needed. Australia’s federal health department agrees.