Most women have used deodorant for years without a second thought, yet following research published last week many might now be thinking twice before applying it.
A potential link between aluminium - commonly found in the form of aluminium salts in anti-perspirants - and breast cancer was found in the study by Chris Exley, at Keele University.
A higher content of aluminium was found in breast tissue samples - taken from 17 women with breast cancer who had mastectomies at Wythenshawe Hospital in Manchester - near the underarm area where anti-perspirants and deodorants are applied. "Although the presence of aluminium in the breast does not, in itself, imply any causal link to breast cancer, it does underline the need for more research, especially in view of the known toxicity of aluminium," says Dr Exley.
Aluminum salts are a form of metal and work by blocking the pores that produce perspiration, hence their use in anti-perspirants. They may be listed in the ingredients on the bottle as aluminium chlorohydrate or aluminium zirconium.
"We know from research that aluminium applied under the arm appears in the urine, so it does permeate through the skin," says Dr Exley, the lead researcher in the Keele study.
Some natural deodorants also use a crystal form of aluminium (known as ammonium alum).
Although these are sold as deodorants rather than anti-perspirants - the ammonium alum is supposed to control the growth of bacteria rather than block the pores - "aluminium found in breast tissue is as likely to come from these aluminium-based natural products as it is from conventional anti-perspirants," says Dr Exley.
Deodorants do not usually contain aluminium as they are designed to prevent odour by using fragrance as well as reducing the levels of underarm bacteria. They may, however, contain parabens, a preservative also found in other cosmetics such as shampoos, body lotions and liquid soaps.
A 2004 study by Dr Philippa Darbre, a senior lecturer in oncology at the University of Reading, found evidence of parabens in breast tumours. "Parabens can mimic the action of oestrogen and there is a link between oestrogen and breast cancer," she says.
Many products act as both antiperspirants and deodorants so may contain both aluminium salts and parabens.
Source - Daily Mail