DDT exposure linked to Alzheimer's

CAMDEN, N.J., Jan. 28 (UPI) -- Exposure to banned pesticide DDT appears to increase a person's Alzheimer's risk.

DDT or dichlorodiphenyltrichloroethane is a colorless, odorless and tasteless pesticide used successfully at the end of World War II to control malaria and protect crops. It was banned in the U.S. in 1972, though the World Health Organization still recommends its use to control malaria.

The study, from Rutgers University and published in the journal JAMA Neurology, tested DDT levels in blood samples taken from a group of healthy people and from people diagnosed with Alzheimer's. They found that 74 of the 86 people in the Alzheimer's group had DDE blood levels four times higher than the 79 healthy people. DDE is the compound that lingers in the body after the breakdown of DDT.

Researchers believe the high levels of the chemical and the presence of the ApoE gene increased the chances of severe cognitive impairment even if patients were lacking the risk gene. DDT is also suspected of aiding the development of amyloid plaque, an indicator of the disease, which leads to the degeneration of brain cells.

Further research will be required as some healthy people exhibited high levels of DDE and some Alzheimer's patients had low levels of DDE.

"It's important to note that this research relates to DDT, a pesticide that has not been used in the UK since the 1980s," said Dr Simon Ridley, the head of research at the charity Alzheimer's Research UK. "While this small study suggests a possible connection between DDT exposure and Alzheimer's, we don't know whether other factors may account for these results.

[Rutgers University] [BBC] [JAMA Neurology]