Linking Alzheimer's to environmental contributors
Scientists have known for more than 40 years that the synthetic pesticide DDT is harmful to bird habitats and a threat to the environment. Now researchers at Rutgers University say exposure to DDT, banned in the United States since 1972 but still used as a pesticide in other countries, may also increase the risk and severity of Alzheimer's disease in some people, particularly those over the age of 60.
In a study published online today in JAMA Neurology, Rutgers scientists discuss their findings in which levels of DDE, the chemical compound left when DDT breaks down, were higher in the blood of late-onset Alzheimer's disease patients compared to those without the disease.
DDT — used in the United States for insect control in crops and livestock and to combat insect-borne diseases like malaria — was introduced as a pesticide during WWII. Rutgers scientists — the first to link a specific chemical compound to Alzheimer's disease — believe that research into how DDT and DDE may trigger neurodegenerative diseases, like Alzheimer's, is crucial.
"I think these results demonstrate that more attention should be focused on potential environmental contributors and their interaction with genetic susceptibility," says Jason R. Richardson, associate professor in the Department of Environmental and Occupational Medicine at Robert Wood Johnson Medical School and a member of the Environmental and Occupational Health Sciences Institute (EOHSI). "Our data may help identify those that are at risk for Alzheimer’s disease and could potentially lead to earlier diagnosis and an improved outcome."
Although the levels of DDT and DDE have decreased significantly in the United States over the last three decades, the toxic pesticide is still found in 75 to 80 percent of the blood samples collected from the Centers for Disease Control and Prevention for a national health and nutrition survey. This occurs, scientists say, because the chemical can take decades to breakdown in the environment. In addition, people may be exposed to the pesticide by consuming imported fruits, vegetables and grains where DDT is still being used and eating fish from contaminated waterways.
In the Rutgers study, conducted in coordination with Emory University Alzheimer's Disease Research Center and the University of Texas Southwestern Medical School’s Alzheimer's Disease Center, 74 out of the 86 Alzheimer's patients involved — whose average age was 74 — had DDE blood levels almost four times higher than the 79 people in the control group who did not have Alzheimer's disease.
Read more at Rutgers University.
Elderly couple image via Shutterstock.