. Smoking lowers risk of Parkinson's disease
Numerous studies have identified the uncanny inverse relationship between smoking and Parkinson's disease. Long-term smokers are somehow protected against Parkinson's, and it's not because smokers die of other things earlier. [10 Easy Paths to Self-Destruction]
The most recent, well-conducted study was published in a March 2010 issue of the journal Neurology. Far from determining a cause for the protective effect, these researchers found that the number of years spent smoking, more so than the number of cigarettes smoked daily, mattered more for a stronger protective effect.
Harvard researchers were among the first to provide convincing evidence that smokers were less likely to develop Parkinson's. In a study published in Neurology in March 2007, these researchers found the protective effect wanes after smokers quit. And they concluded, in their special scientific way, that they didn't have a clue as to why.