Study explores environmental link for Parkinson's Disease

A family-based case-control study explores the link between risk of Parkinson's disease, cigarette smoking or caffeine consumption and the use of non-steroidal anti-inflammatory drugs (NSAIDs).Dr Dana Hancock (Duke University Medical Centre ) and colleagues comment that whilst cigarette smoking, caffeine, and use of NSAIDs are reported to protect against the development of Parkinson's disease, few family-based studies have evaluated these associations.They add that family-based case-control data sets are helpful for genetic association studies, because the design minimises confounding by ethnic background and allows good matching of case patients and family control subjects for unmeasured genetic and environmental factors.Using a family-based case-control design, the authors' evaluated 356 patients with Parkinson's disease and 317 family control subjects self-reported environmental exposures.Hancock's group report that individuals with Parkinson's disease were less likely to report ever or current smoking, compared with unaffected relatives. Additionally, dosage, duration, and intensity of smoking, as well as status (never, ever, current), were inversely associated with Parkinson's disease (pIncreasing intensity of coffee drinking and total caffeine consumption and intensity were also linked to a reduced association with Parkinson's disease.The authors also found no significant associations between "nonsteroidal anti-inflammatory drugs and Parkinson's disease", or between non-aspirin NSAID use and Parkinson's disease.Commenting on their findings Hancock et al state that despite epidemiologic support for these environmental factors in neuroprotection, the biological mechanisms, "if existent, have eluded investigators". They add that some investigators have proposed that the inverse associations with smoking and caffeine may alternatively reflect a preclinical Parkinson's disease state of aversion, when smoking and consuming caffeine may be less rewarding.Reference...