Researchers have this week found a link between Alzheimer's disease and the pesticide, DDT. Alzheimer's patients have four times the level of the toxins in their blood compared to a healthy person-even though the pesticide has been banned for more than 40 years in the West.
The Alzheimer's victims had high levels of DDE, the chemical compound that remains after DDT breaks down, say researchers at Rutgers University, who analysed blood samples from 86 patients and compared them to 79 people who didn't have the degenerative disease. Of the 89, 74 had levels of DDE that were four times higher than that found in the blood of the healthy controls.
But why was DDE there at all if the pesticide has been banned in the US since 1972? Around 80 per cent of all blood samples still carry traces of DDE, says the US's Centers for Disease Control and Prevention. This is because it can take decades for the chemical to break down, and people may still be exposed to DDT from fruits and vegetables that are sourced from abroad. It can also be found in fish that swim in polluted waters.
(Source: JAMA Neurology, 2014; doi: 10.1001/jamaneurol.2013.6031)