PISCATAWAY, NEW JERSEY. A study just published examined the correlation between the levels of DDE, a metabolite of the infamous pesticide DDT, and the risk of developing Alzheimer's disease. Using the case-control format, 86 cases of late-onset AD were compared to 79 controls. Levels of DDE were 3.9-8 fold higher in the blood of those with AD when compared to the controls. This translated into a 4.18 fold increase in risk AD in the highest tertile of DDE levels and this was accompanied by evidence of increased severity. Blood levels of DDE were also highly correlated with brain levels of this toxin found at autopsy. It was also found that carriers of the APOE4 genetic predisposition to AD were more susceptible to the adverse effects of DDE. While DDT is no longer allowed in many countries, there is a large environmental residue from long and extensive prior use.

Richardson JR, Roy A, Shalat SL et al. Elevated Serum Pesticide Levels and Risk for Alzheimer Disease. JAMA Neurol. 2014