DDT Pesticide Linked to Alzheimer's
DDT, not used in the US since 1972, may increase your chances of developing Alzheimer’s according to scientists at Rutgers University and Emory University. The study examined the association between Alzheimer's disease and blood levels of DDE (dichlorodiphenyldichloroethylene). DDE is a by-product of the pesticide DDT (dichlorodiphenyltrichloroethane).
Eighty-six people with Alzheimer’s disease were compared with 79 healthy people without the disease. They found that the bloods of people with Alzheimer’s had levels of DDT that were 3.8 times higher than those without the disease. The study also found that people with higher levels of DDT performed the worst in cognitive function tests.
DDT is a colorless and almost odourless pesticide that was initally used to control malaria and was later used in agriculture. Swiss scientist Paul Muller discovered its insectacidal action in 1939 and it became a very popular pesticide. Its widespread and indiscrimiate use only stopped when it was realized that DDT was causing huge damage to wildlife and it was thought to cause some cancers and other health problems in humans.
Environmental pollutants have previously been suggested as having a role in the development of Alzheimer’s. Mercury is one such example. The main sources of mercury in humans are in dental amalgam and fish. A study from the University of Freiberg found higher mercury concentrations in brain regions and the blood of some patients with Alzheimer's disease (AD). Low levels of inorganic mercury were able to cause AD-typical nerve cell deteriorations in vitro and in animal experiments.
Metals, pollutants and some diseases shows that metals do cause memory loss and confusion. Examples are Wilson's disease where copper builds up in the brain, in lead and thallium poisoning, from some medications such as lithium and carbon monoxide poisoning.
Whether the DDT research from Rutgers University and Emory University published in JAMA Neurology has much effect on the causation of Alzheimer’s is open to question. The team in this study believe the chemical increases the chance of Alzheimer's and may be involved in the development of amyloid plaques in the brain, a hallmark of the disease. Alzheimer’s, of course, predates the discovery and the widespread use of DDT so a lot more research is required. However the numbers of people shown to be affected by this chemical is significant enough to make it of interest.
Meanwhile the World Health Organization still recommends DDT’s use to control disease but in a more limited way.