Mayo Clinic researchers have found that using pesticides
for farming or other purposes increases the risk of developing
Parkinson's disease for men. Pesticide exposure did not
increase the risk of Parkinson's in women, and no other
household or industrial chemicals were significantly linked
to the disease in either men or women.
Findings will be published in the June issue of the journal
Movement Disorders.
"This confirms what has been found in previous studies:
that occupational or other exposure to herbicides, insecticides
and other pesticides increases risk for Parkinson's," says
Jim Maraganore, M.D., Mayo Clinic neurologist and study
investigator. "What we think may be happening is that pesticide
use combines with other risk factors in men's environment
or genetic makeup, causing them to cross over the threshold
into developing the disease. By contrast, estrogen may protect
women from the toxic effects of pesticides."
The investigators identified all those in Olmsted County,
Minn., home of Mayo Clinic, who had developed Parkinson's
disease between 1976 and 1995. Each person with Parkinson's
disease was matched for comparison to someone similar in
age and gender who did not have the disease. The researchers
conducted telephone interviews with 149 of those with Parkinson's
and 129 of those who did not have the disease, or a proxy
for these people, to assess exposure to chemical products
via farming occupation, non-farming occupation or hobbies.
The investigators were unable to determine through these
interviews the exact exposure levels of these individuals
or the cumulative lifetime exposure to pesticides.
Overall, the study found that the men with Parkinson's
were 2.4 times more likely to have had exposure to pesticides
than those who did not have Parkinson's. Women who had Parkinson's,
on the other hand, had a far lower frequency of exposure
to pesticides than men with the disease.
This study was undertaken due to conflicting results from
previous studies of pesticides and other chemical products
and risk for Parkinson's.
