Some people are concerned that antiperspirants can cause breast cancer. Others worry about getting Alzheimer’s disease. WebMD interviewed a number of experts asking “Should we worry?” and the consensus is in short: No. There is no real scientific evidence that aluminum or any of the other ingredients in these products pose any threat to human health.
According to WebMD, “Most antiperspirant worries center on the active ingredient -- an aluminum-based compound that temporarily plugs the sweat ducts and prevents you from perspiring.” The article goes on to say, "There is no convincing evidence that antiperspirant or deodorant use increases cancer risk," Ted S. Gansler, MD, MBA, director of medical content for the American Cancer Society.
Another myth circulating is the link between Alzheimer’s and aluminum. According to Heather M. Snyder,
“The aluminum salts do not work as antiperspirants by being absorbed in the body. They work by forming a chemical reaction with the water in the sweat to form a physical plug... which is deposited in the sweat duct, producing a blockage in the areas that it's applied," says David Pariser, MD, professor of dermatology at Eastern Virginia Medical School and past president of the American Academy of Dermatology.