Study: Pesticides May Trigger Parkinson’s

Nov. 6 -- New research using rats suggests that long-term exposure to a widely used pesticide kills brain cells and triggers debilitating physical symptoms associated with Parkinson’s disease.

Scientists say the experiment’s results strongly indicate whatscientists have suspected for several years — that the most commonform of Parkinson’s disease might result from toxins in theenvironment.

The new study, published in the December issue of NatureNeuroscience, does not prove that the pesticide used in the test,rotenone, causes Parkinson’s in humans.

But scientists who reviewed the experiment said the results arepowerful and should reinvigorate the search for environmentaltoxins that may contribute to Parkinson’s, the most commonneurological disorder after Alzheimer’s.

Evidence of Increased Risk

“This is more evidence that a class of compounds may increasethe risk of developing Parkinson’s,” said J. William Langston,director of the Parkinson’s Institute in Sunnyvale, Calif., who wasnot involved in the study. “It is not direct evidence thatrotenone causes Parkinson’s. The whole puzzle hasn’t cometogether.”

More than a million Americans suffer from Parkinson’s.

Muscle control ebbs as brain cells in a region called thesubstantia nigra produce less dopamine, a hormone vital to normalnerve function. The illness is marked by small tremors, such asfacial tics and shaking hands. Advanced symptoms include ashuffling gait, speech difficulties and muscle weakness.

There is no cure, and current drug and surgical therapies tendsto lose effectiveness over time. New therapies involvingtransplants of stem cells, the body’s master cells from which alltissues grow, have been slowed by federal funding restrictions onexperiments using embryonic tissues.

In about 10 percent of patients, Parkinson’s strikes before age50. These rare cases probably are caused by inherited geneticabnormalities.