Did mom or dad have Parkinson's? According to a medical meta-analysis having a family history of PD is the most significant single risk indicator.
"People with a first-degree relative with PD had a more than threefold higher odds for developing PD themselves, compared with those without an affected first-degree relative, based on a meta-analysis of data from 26 case-control studies, and people with any relative with PD had a 4.5-fold greater odds, according to data collected in 19 case-control studies."While 4.5-fold odds sounds like a lot on average only 1.6 out of 100
men of European ethnicity will develop Parkinson's Disease between the ages of 30 and 79. So if you have a family history of PD, indicative of a genetic factor, that's 7.2%, still significantly less than the average risk of developing prostate cancer, and about on a par with the average risk of developing age-related macular degeneration.
The study also found that a family history of tremour boosted the odds for development of PD 2.7-fold.
Many environmentally-related factors are identified in the report, including that current smokers had 56% lower odds of PD, compared with never-smokers. Coffee drinking was linked to a 33% drop in odds. Caffeine may also help reduce the severity of PD.