Some information I ran into researching the two diseases for a friend. I had already seen the nicotine/Parkinson’s connection in real life.
http://www.medscape.com/viewarticle/746713
Abstract
The risk of Parkinson’s disease is reduced by cigarette smoking, which raises some unanswered questions. Nicotine, a major component of tobacco smoke, could exert either nonreceptor-mediated biological effects or, more importantly, act on the different subtypes of nicotinic brain receptors, in particular those associated with the nigrostriatal dopaminergic pathway. There is now robust experimental evidence for a neuroprotective effect of nicotine upon dopaminergic neurons
https://www.georgetown.edu/news/slowing-down-of-alzheimers-may-involve-nicotine.html
January 9, 2012 – Nicotine patches may one day slow the progression of mild cognitive impairment (MCI) to Alzheimer’s disease, according to a study Georgetown professors and other researchers will have published tomorrow in the journal Neurology.
Georgetown University Medical Center (GUMC) was one of three academic medical centers participating in the study, which showed that six months of nicotine patch treatment resulted in patients regaining up to 46 percent of normal performance for their age on certain long-term memory tests. The placebo group worsened by 26 percent during that time.
Is it your claim that smoking is good for society? Run with that, it’s a winner.