Study confirms Parkinson's-pesticides link

NEW YORK (Reuters Health) - Results of a family-based, "case-control" study support a relationship between exposure to pesticides and the development of Parkinson's disease (PD).

Prior studies have shown that people with Parkinson's disease are over twice as likely to report being exposed to pesticides as people without the disease, but few studies have looked at this association in people from the same family or have assessed associations between specific classes of pesticides and Parkinson's disease.

In their study of 319 Parkinson's patients and more than 200 unaffected relatives, Dr. Dana Hancock from Duke University, Durham, North Carolina and colleagues found that the Parkinson's patients were 61 percent more likely to report direct pesticide application than were healthy relatives.

Both insecticides and herbicides -- most notably organochlorines, organophosphorus compounds, chlorophenoxy acids/esters, and botanicals -- significantly increased the risk of Parkinson's disease, the researchers report in the online journal BioMedCentral (BMC) Neurology.

"Further investigation of these specific pesticides and others may lead to identification of pertinent biological pathways influencing Parkinson's disease development," the investigators suggest.

It's also worth noting, they say, that "the strongest associations between Parkinson's disease and pesticides were obtained in families with no history of Parkinson's. "This finding suggests that sporadic Parkinson's cases may be particularly vulnerable to the toxic effects of pesticides, but the possibility of pesticides influencing risk of Parkinson's in individuals from families with a history of PD cannot be ruled out."

SOURCE: BioMedCentral-Neurology 2008.