Researchers link DDT exposure to increased risk of Alzheimer's in elders

(http://www.cbsnews.com) A new report published in JAMA Neurology shows that the pesticide DDT may increase the risk of Alzheimer's disease in elderly adults.

The study found that, on average, people with Alzheimer's had four times as much DDE, a metabolite of DDT, in their blood as did people without the neurodegenerative condition.

DDT was used agriculturally in America for decades until being banned in 1972. However, other countries still use the chemical, particularly to control mosquitoes and diseases like malaria, and it may be found on contaminated fruits and vegetable imported into the U.S. Because of this, and the fact that "DDE persists in the environment for a long time," Americans are still regularly exposed to the chemical.

To find the health impacts of DDT, researchers compared a group of 86 elderly adults with Alzheimer's to a group of 79 healthy persons of a similar age. What they found was that the third of persons who had the highest amount of DDE were four times more likely to suffer from Alzheimer's.

The researchers also examined cultured nerve cells exposed to DDT and DDE and found an increase in the levels of a protein that is a precursor to beta-amyloid, which clumps together in the brain to form the plaques associated with Alzheimer's disease.