At last! Here's a good reason to smoke cigarettes: they prevent Parkinson's Disease.
Actually, they've known this for some time, but nobody has been able to explain why it is that cigarette smokers are less likely to develop Parkinson's.
Apparently, a compound in tobacco that is a derivative of naphthoquinone, preserves dopamine by interfering with an enzyme in the brain known as monoamine oxidase (MAO). MAO typically breaks down neurotransmitters - including dopamine, serotonin, and norepinephrine - as part of normal chemical activity in the brain.
I'm guessing they'll find another way to get the useful compound, but for now, smokers can tell everyone else to shut-up, for once.