Antiperspirants do increase risk of breast cancer

Antiperspirant use is a risk factor for breast cancer, according to scientists.

We recently learned that the Swiss government was considering banning the use of aluminium salts in antiperspirants. In making up their mind they would do well to heed the results of an epidemiological study just published in EBioMedicine which show that the use of antiperspirants is a risk factor for breast cancer.

In the largest study of its kind, the team based at the Medical University of Innsbruck, Austria, conducted an age-matched case-controlled study, involving 209 female breast cancer patients and 209 healthy controls, to investigate breast cancer and the self-reported use of underarm cosmetic products.

They found that the use of antiperspirants was significantly associated with breast cancer risk. This risk was increased substantially (Odds Ratio of 3.88) in individuals who applied antiperspirant more than once a day before they had reached the age of 30.

The alarming conclusion is that frequent use of antiperspirants in females under the age of 30 predisposed them to a significantly higher risk of breast cancer in later life.

The team also made measurements of aluminium in breast tissue and they found a significantly higher content of aluminium in breast tissue in breast cancer than in controls. Previous research in the field has suggested that the aluminium content of breast tissue in individuals with breast cancer was higher in tissue closer to the underarm, the area of the breast with the highest incidence of breast tumours.

Aluminium-based antiperspirants are effective because they are a significant source of biologically-reactive aluminium (Al3+(aq)) which inhibits the activity of sweat glands in the area of application of the product, most often the underarm. Aluminium may accumulate in breast tissue as a result of the application of aluminium salts to the skin but also because perspiration is a major route of excretion of aluminium from the body and therefore preventing sweating will also prevent the excretion of aluminium from sweat glands in the underarm region. These are two very good reasons why the aluminium content of breast tissue close to the underarm region is higher than elsewhere.

Aluminium has been a suspected human carcinogen for more than 100 years. The findings in this new paper confirm that aluminium can now be added to the list of carcinogens which are known to contribute towards the aetiology of breast cancer.