Over .01 percent of the aluminum in typical antiperspirant can be absorbed after a single underarm antiperspirant application. Folks, this adds up over time and that aluminum can and does go straight to your brain where it can play havoc.
A post earlier this week showed that there will be 16 million with Alzheimer's by the time many of you are reading this will be elderly (2050). Fortunately, there are simple things you can do to prevent Alzheimer's.
Personally I stopped using antiperspirant nearly 20 years ago. All I do is use simple soap and water, and it works splendidly. Interestingly, those stains that occurred on my shirts stopped on all my new shirts as it was due to an interaction with the antiperspirant and my sweat, not the sweat alone.
Deodorants aren't as bad, but I would also avoid using them unless it was some form of baking soda.
Pharmacological Toxicology April 2001;;88(4):159-67