Tip out the contents of any woman's toiletry bag and you'll find deodorant, body lotion, sunscreen and shampoo, all of which may contain parabens – widely used preservatives that come under the heading of endocrine-disrupting chemicals – meaning that if they get into the body in high enough doses they can potentially act like hormones.

Should we worry? That depends on who you ask. Parabens, which can be absorbed through the skin, can mimic the female hormone oestrogen and there are concerns that they may be linked to breast cancer. Too much oestrogen in a woman's body can raise her breast cancer risk and the fact that studies have found traces of parabens in breast cancer tissue has some scientists wondering if these chemicals may contribute to breast cancer by increasing the oestrogen 'load' in a woman's breast.

Parabens are in many of the beauty products we use.

There's no shortage of soothing messages saying that levels of parabens in personal care products are so low they're not a problem – the Cancer Council Western Australia places concerns about parabens firmly under the heading of 'cancer myths', saying that the Cosmetic Ingredient Review, a US-based organisation that assesses the safety of cosmetic ingredients, has reviewed the safety of parabens and concluded that they're safe for use in cosmetics.

But now and again research pops up that makes you wonder about your body lotion. The latest, a study in cells, not humans, from the University of California Berkeley and funded by the California Breast Cancer Research Program found that even at low levels parabens could stimulate the growth of breast cancer cells when they interact with a growth factor that's naturally produced in a woman's body.