Occupation and Education Influence Risk for Parkinson's Disease

Mayo Clinic researchers have found that an individual's educational and career paths impact Parkinson's disease risk later in life. This report will appear in the Nov. 22 issue of the journal Neurology, http://www.aan.com/publications/journal/

The investigators, led by Walter Rocca, M.D., a Mayo Clinic epidemiologist, discovered the highest increase in Parkinson's risk in people with nine or more years of education. They also found that risk level rises as years of schooling increase. Occupationally, physicians had the greatest increased risk for Parkinson's compared to the general population, while those employed as construction and extractive workers (e.g., miners, well drillers), production workers (e.g., machine operators, fabricators), metalworkers and engineers had the lowest risk increase. The researchers also note that this study did not find farmers and other agricultural workers at increased risk for Parkinson's.

The Mayo Clinic investigators advise caution in interpreting this study. "Our findings for education and occupation are complex, and therefore they need to be interpreted with care," says Roberta Frigerio, M.D., the study’s first author and former Mayo Clinic research fellow. “These factors may be surrogates for a variety of exposures, physical activity, personality or socioeconomic status. Further studies are needed to interpret our findings.”

Demetrius (Jim) Maraganore, M.D., Mayo Clinic neurologist and study investigator, agrees. “We really can’t say from this study that education and occupation are causal factors in Parkinson’s disease; we can only say that they are associated,” says Dr. Maraganore. “I don’t think that schooling or wearing a stethoscope causes brain cells to degenerate or that digging holes with a digger protects your brain cells from atrophy, but I think that these are indirect indicators of factors that may relate to brain degeneration. And now what we need to do is use these clues to try and identify those molecular level events that differentiate these people.”

Suggested Applications of Study Findings

The utility of the study’s findings concerning occupation, education and Parkinson’s disease risk is primarily informational rather than actionable for members of the public, according to Dr. Maraganore. This is especially true in light of the relatively low overall lifetime risk for Parkinson’s for any given person, he says.

“Really, nobody should do anything differently based on these findings,” says Dr. Maraganore. “These findings are not at all intended to change anybody’s behaviors. I think that the bottom line is that we’re talking about going from a baseline risk of 2 percent to develop Parkinson’s disease during a lifetime to a risk of 4 percent if you are highly educated or a physician, or 1 percent if you are less educated or more physically active. So, I wouldn’t change your schooling plans or your occupation based on these findings. I would just welcome these findings as new clues about possible causes of Parkinson’s disease that will hopefully lead to the ultimate answers.”