A French group presented data at the 20th International Congress of Parkinson’s Disease and Movement Disorders in Berlin Germany last month. Their results suggested a strong link between farming, pesticides and risk of Parkinson’s disease. Sofiane Kab and her colleagues demonstrated that living in rural French regions with more crops was a high risk for the later developing Parkinson’s. The authors noted that these are typically regions where vineyards are located. The study used the French National Health Insurance databases and showed that there were more cases of Parkinson’s diagnosed in rural France. This study adds to other compelling evidence that farming and pesticide exposure are related to Parkinson’s risk. Collectively, many studies show that Parkinson’s seems to be closely associated with rural living and pesticide exposure.
Pesticides, Agent Orange, and potential environmental risk factors for the development of Parkinson’s continue to make the news. Patients and families may be confronted by worrisome headlines on chemicals and Parkinson’s.
Drs Samuel Goldman and Carly Tanner from the Sunnyvale Parkinson’s Institute previously studied twins from a WWII Veterans Cohort. By utilizing twin pairs (half were identical twins), researchers limited the potential effects of genetics on the development of Parkinson’s. One person from each twin pair was required to have been diagnosed with Parkinson’s. A very careful occupational and hobby history was then extracted. First hand histories from patients were sparse with spouses and siblings providing secondhand proxy histories in most cases. An occupational hygienist was used to help determine exposure. An occupational hygienist is a carefully trained professional who can independently determine exposures, hazards, or risks in a workplace environment. The hygienist, along with the researchers, examined six solvents and determined that only trichloroethylene (TCE) was associated with an increased risk (6.1 times) of developing Parkinson’s in men. Additionally, men exposed to TCE or another chemical called PERC (tetrachloroethylene) had an 8.9 times increased risk of developing Parkinson’s.
Interestingly n-hexane, xylene and toluene, which have all been thought to be potentially associated with the development of Parkinson’s, did not show an increased risk in this cohort. All of the studies of environmental exposures should be interpreted with caution, and patients and families should look for common themes among multiple research reports as there is potential for error in these types of population-based studies (Okun, MS, 2013).
Patients and families should appreciate that more information will be needed to determine which pesticides and what kind of exposures would significantly impact the later risk of Parkinson’s. Collectively, we now appreciate that farming, pesticides, and other chemical exposures may be related to the later risk of developing Parkinson’s.
Kab S. 20th International Congress of Parkinson’s Disease and Movement Disorders, Berlin Germany, 2016.
Okun MS. Parkinson’s Treatment: 10 Secrets to a Happier Life, Books4Patients, 2013.
You can find out more about our National Medical Director, Dr. Michael S. Okun, by also visiting the Center of Excellence, University of Florida Health Center for Movement Disorders and Neurorestoration. Dr. Okun is also the author of the Amazon #1 Parkinson's Best Seller 10 Secrets to a Happier Life and 10 Breakthrough Therapies for Parkinson's Disease. You can read more from Dr. Okun in the What's Hot in PD? archives.