Apples for Health- Data Link Insecticide And Parkinson's

Researchers report the discovery of a possible link between a common insecticide and the development of Parkinson's disease.

"We have found fairly low-dose effects of permethrin, an insecticide used by the military and on food crops" on a brain protein and dopamine uptake levels, reported Jeffrey Bloomquist, a professor of toxicology and pharmacology at Virginia Polytechnic Institute in Blacksburg. "These changes could lead to Parkinson's disease," he told United Press International.

Bloomquist and his colleague Bradley Klein, professor of neurobiology at the Virginia-Maryland Regional College of Veterinary Medicine, also in Blacksburg, presented results of their U.S. Army-funded research at the annual meeting of the American Chemical Society.

They found low levels of the insecticide -- commonly used to protect cotton, corn and other crops from insect devastation -- were related to lower dopamine production. A decrease in this neurotransmitter's production in the brain has been linked in previous research to the loss of motor skills associated with Parkinson's.

In addition, permethrin, also used to "impregnate (troops') uniforms to repel insects," affected levels of the protein alpha-synuclein, Bloomquist said. His research suggested too much of this protein could cause formation of Lewy bodies -- fibrous clumps seen in the brains of Parkinson's patients.

Though changes in the brain's neural pathways caused by permethrin exposure could lead to Parkinson's, Bloomquist said the research has not established a conclusive link. The changes are consistent with a pre-Parkinson's condition, but not the full-blown disease, he explained, adding genetics also plays a probable role in a person's susceptibility to Parkinson's.

The U.S. Army, which funded the initial research, has indicated support for additional studies, Bloomquist said.

"We want to look at longer exposure to see if we get something that looks like full-blown Parkinson's," he added. The results presented at the ACS meeting were based on injections administered over relatively short, two-week periods.

The research fits into a larger category of association between insecticides and Parkinson's. One clue to the link is the relatively elevated risk for the disease in areas where insecticides are commonly used.

"There has been similar work done," said Dr. Charles Adler, professor of neurology at the Mayo Clinic in Scottsdale, Ariz. "The epidemiological data suggest people in rural areas have higher rates of Parkinson's."