New study links higher blood levels of DDE (breakdown product of DDT) to quote] to Alzheimer's.
http://archneur.jamanetwork.com/article.aspx?articleid=1816015
Elevated Serum Pesticide Levels and Risk for Alzheimer Disease
Jason R. Richardson, PhD1,2; Ananya Roy, ScD2; Stuart L. Shalat, ScD1,2; Richard T. von Stein, PhD2; Muhammad M. Hossain, PhD1,2; Brian Buckley, PhD2; Marla Gearing, PhD4; Allan I. Levey, MD, PhD3; Dwight C. German, PhD5
JAMA Neurol. Published online January 27, 2014. doi:10.1001/jamaneurol.2013.6030
Importance The causes of late-onset Alzheimer disease (AD) are not yet understood but likely include a combination of genetic, environmental, and lifestyle factors. Limited epidemiological studies suggest that occupational pesticide exposures are associated with AD. Previously, we reported that serum levels of dichlorodiphenyldichloroethylene (DDE), the metabolite of the pesticide dichlorodiphenyltrichloroethane (DDT), were elevated in a small number of patients with AD (n=20).
Objective To evaluate the association between serum levels of DDE and AD and whether the apolipoprotein E (APOE) genotype modifies the association.
Design, Setting, and Participants A case-control study consisting of existing samples from patients with AD and control participants from the Emory University Alzheimer’s Disease Research Center and the University of Texas Southwestern Medical School’s Alzheimer’s Disease Center. Serum levels of DDE were measured in 79 control and 86 AD cases.
Main Outcomes and Measures Serum DDE levels, AD diagnosis, severity of AD measured by the Mini-Mental State Examination score, and interaction with APOE4 status.
Results Levels of DDE were 3.8-fold higher in the serum of those with AD (mean [SEM], 2.64 [0.35] ng/mg cholesterol) when compared with control participants (mean [SEM], 0.69 [0.1] ng/mg cholesterol; P < .001). The highest tertile of DDE levels was associated with an odds ratio of 4.18 for increased risk for AD (95% CI, 2.54-5.82; P < .001) and lower Mini-Mental State Examination scores (−1.605; range, −3.095 to −0.114; P < .0001). The Mini-Mental State Examination scores in the highest tertile of DDE were −1.753 points lower in the subpopulation carrying an APOE ε4 allele compared with those carrying an APOE ε3 allele (P interaction = .04). Serum levels of DDE were highly correlated with brain levels of DDE (ρ = 0.95). Exposure of human neuroblastoma cells to DDT or DDE increased levels of amyloid precursor protein.
Conclusions and Relevance Elevated serum DDE levels are associated with an increased risk for AD and carriers of an APOE4 ε4 allele may be more susceptible to the effects of DDE. Both DDT and DDE increase amyloid precursor protein levels, providing mechanistic plausibility for the association of DDE exposure with AD. Identifying people who have elevated levels of DDE and carry an APOE ε4 allele may lead to early identification of some cases of AD.
Notes from Food-navigator:
http://www.foodnavigator.com/Science-Nutrition/Pesticide-exposure-may-be-linked-to-Alzheimer-s-disease-Study
While it is true that levels of DDT and DDE have decreased significantly globally since its ban, data from blood samples collected by the US Centers for Disease Control and Prevention as part of a national health and nutrition survey show that the toxic pesticide is still found in 75 to 80% of the people's blood.
This occurs because the chemical can take decades to breakdown in the environment, said the team.
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, they added.
