New research shows that patients with Alzheimer’s disease have significantly higher levels of DDE, the long-lasting metabolite of the pesticide DDT, in their blood than healthy people.
The study at Emory University School of Medicine involved 86 Alzheimer’s patients and 79 healthy elderly controls. Researchers found that DDE levels were almost four times higher in serum samples from Alzheimer’s patients than in healthy controls. Having DDE levels in the highest third of the range in the study increased someone’s risk of Alzheimer’s by a factor of four.
Researchers also identified a plausible mechanism by which DDE and DDT have Alzheimer’s-related effects on the brain. Exposure of neural cells to high concentrations of DDE or DDT increases levels of the protein that is a precursor to beta-amyloid, the main component of plaques found in the brains of Alzheimer’s patients.