Didn't Michael J. Fox smoke almost as much as I do?\
I can actually see nicotine warding off something like that though...most naturally occurring drugs have some sort of purpose.
Scientists noticed a remote group in South America a few years ago who drink a tea that is pretty much MDA. They have no incidence of Alzheimers there and preliminary scientific results show that the tea can actually reverse Alzheimers to some extent.
Meanwhile the kids are getting all loaded up on ecstasy...the same basic drug. We tell them they are bad for doing it.