Hi All,
I'm currently performing a year of medical research and thought some of you might be interested to hear one of my findings.
Smoking has been shown to be a negative risk factor for the development of Parkinson's Disease. That is, smokers have lower rates of Parkinson's Disease than non-smokers. Your first reaction may be that smokers die before they have the chance to develop Parkinson's Disease - but the numerous studies have taken this possibility into account during their statistical analysis and it is not the case.
The difference in risk is pretty substantial - a smoker has 60% less risk than the non-smoker of developing Parkinson's Disease.
These studies have been comparing cigarette smokers to non-smokers. But the physiological models are based upon the effect of nicotine on the body, so I don't see why this same effect would not also be true of cigar smokers.
Anyway, for those interested in further reading here some of the studies that support this finding:
Abbott RD, Ross GW, White LR, Sanderson WT, Burchfiel CM, Kashon M, Sharp DS, Masaki KH, Curb JD, Petrovitch H, Abbott RD, Ross GW, White LR, Sanderson WT, Burchfiel CM, Kashon M, Sharp DS, Masaki KH, Curb JD, Petrovitch H (2003) Environmental, life-style, and physical precursors of clinical Parkinson's disease: recent findings from the Honolulu-Asia Aging Study. Journal of Neurology 250 Suppl 3:III30-39
de Lau LML, Breteler MMB (2006) Epidemiology of Parkinson's disease. The Lancet Neurology 5:525-535
Miguel A. Hernán BTFC-IJJG-O (2002) A meta-analysis of coffee drinking, cigarette smoking, and the risk of Parkinson's disease. In, pp 276-284