Scientists in Britain suggest they may have found a possible link between the use of deodorants and breast cancer.
The scientists from the Birchall Centre for Inorganic Chemistry and Materials at Keele University measured the aluminium content of breast tissue from 17 breast cancer patients recruited from Wythenshaw Hospital, Manchester; they say they have found that the aluminium content of breast tissue and breast tissue fat was significantly higher in the outer regions of the breast, in close proximity to the area where there would be the highest density of antiperspirant.
The breast cancer - deodorant link is not a novel one and recent research has questioned the significance of aluminium-based, underarm antiperspirants because of the known, but unaccountable higher incidence of tumours in the upper outer quadrant of the breast.
However while the link has been hard to prove this latest study has identified a specific distribution of aluminium in breast tissue in that region which may have implications for the cause of breast cancer.
The team, led by Dr. Chris Exley measured the aluminium content in the breast tissue in order to establish if the distribution of aluminium in the breast was related to the higher incidence of tumours in the outer upper quadrant of the breast.
Antiperspirant is mainly made up from aluminium salts which have long been associated with cancer, as well as other human disease and the daily application of aluminium-based antiperspirants could possibly result in the presence of aluminium in the tissue of the underarm and surrounding areas.
While there is little data on aluminium in breast tissue, breast cancer is the most common malignancy in women and the leading cause of death among women aged 35-54.
Experts believe it is caused by a combination of generic and environmental factors.
Each of the patients involved in the study had undergone a mastectomy and biopsies from four different regions of the breast.
When the tissue was tested it showed that while there were significant differences in the concentrations of aluminium between individuals they did show 'a statistically higher concentration of aluminium in the outer as compared with the inner region of the breast'.
The researchers say the higher content of aluminium in the outer breast might be explained by this region's closer proximity to the underarm where the highest density of application of antiperspirant is used; they also say evidence exists that skin is permeable to aluminium when applied as antiperspirant.
They also say however that they found no direct evidence that the aluminium measured in these breast biopsies originated from antiperspirant and an alternative explanation might be that tumourous tissue acts as a 'sink' for systemic aluminium.
The researchers say aluminium is a metalloestrogen (metallic compound capable of binding to cellular oestrogen receptors and then mimicking the actions of physiological oestrogens) and is genotoxic (known to damage DNA) and has been shown to be carcinogenic.
Experts say there is still no good evidence to suggest that either deodorant or antiperspirant use, or exposure to aluminium can increase the risk of developing breast cancer, which they say is a complex disease the causes of which are unknown for the majority of women diagnosed with it each year.
Aluminium is the third most common and naturally abundant element in the environment; it is found in food, water, pharmaceuticals and many consumer products.
The study is published in the Journal of Inorganic Biochemistry.