For several years rumors have circulated, primarily on the Internet, claiming that the use of antiperspirant deodorants can cause breast cancer. But no clear scientific basis has been found to substantiate these rumors.

According to the National Cancer Institute, “researchers at the NCI are not aware of any conclusive evidence linking the use of underarm antiperspirants or deodorants and the subsequent development of breast cancer. The U.S. Food and Drug Administration, which regulates food, cosmetics, medicines, and medical devices, also does not have any evidence or research data that ingredients in underarm antiperspirants or deodorants cause cancer.”

These rumors have two basic premises. They claim that antiperspirants (because they block perspiration) prevent the body from flushing “toxins,” which then accumulate in the lymph nodes of the armpits and cause cancer. Other reports speculate that potentially harmful ingredients in some of these products, including a group of chemicals called parabens, might enter the body through nicks caused by underarm shaving and cause breast cancer.

A small study did find parabens in eighteen of twenty samples of breast cancer tissue. But since the study failed to establish whether the samples were from women who used deodorants or antiperspirants containing parabens, or even the source of the parabens in the samples (parabens are present in a variety of foods, medicines, and cosmetics)-it certainly doesn’t provide proof of any relevant hypothesis.

A recent study involving breast cancer survivors found that women who used underarm antiperspirants/deodorants and shaved their underarms frequently were diagnosed with cancer at younger ages, but the study stopped short of showing a clear link.

In 2002 a study was conducted at the Fred Hutchinson Cancer Research Center in Seattle. This research, which involved some 1,606 women-813 with breast cancer, and 793 controls-indicated no relationship between breast cancer and use of either and antiperspirant or a deodorant.