Parkinson's disease linked to exposure to pesticides

Recent research suggests a possible link between exposure to pesticides and the development of Parkinson's disease (PD).

The research by Dr. Dana Hancock from Duke University, Durham, North Carolina and colleagues involved 319 PD patients and more than 296 unaffected relatives, and found that the PD patients were 61 percent more likely to report direct pesticide exposure than were their healthy relatives.

The results of the family-based, "case-control" study supports other research which has found that people with PD are more that twice as likely to report being exposed to pesticides as people without the disease.

However not many studies have investigated this association in people from the same family or between specific classes of pesticides and Parkinson's disease, even though pesticides and correlated lifestyle factors such as exposure to well-water and farming are repeatedly reported as risk factors for PD.

The researchers say both insecticides and herbicides significantly increased the risk of Parkinson's disease even after factors such as age, sex, cigarette smoking, and caffeine consumption were allowed for.

The research team suggests that further investigation into specific pesticides may lead to information on how biological pathways influence the development of Parkinson's disease.

They note that "the strongest associations between Parkinson's disease and pesticides were obtained in families with no history of Parkinson's which they say suggests that sporadic Parkinson's cases may be particularly vulnerable to the toxic effects of pesticides."

They also say the possibility of pesticides influencing risk of Parkinson's in individuals from families with a history of PD cannot be ruled out.

Parkinson's disease is characterized by progressive tremors, rigidity, and impairs the sufferer's motor skills and speech.

While PD is not considered to be a fatal disease, it progresses with time and the average life expectancy of a PD patient is generally lower than for people who do not have the disease.

The research can be found in the online journal BioMedCentral Neurology.