Alzheimer’s disease is one of the most dreaded diseases of all. Many people would rather lose almost anything before losing their minds. The causes of Alzheimer’s disease are likely a combination of genetic, environmental, and lifestyle factors. Researchers from Rutgers University recently found that elevated blood levels of DDE, the metabolite of the banned pesticide DDT, increased the risk of developing Alzheimer’s disease.

People with the highest DDE levels were four times more likely to have Alzheimer’s disease than people with the lowest levels, according to the study, which was published in the Journal of the American Medical Association. Those individuals with a certain gene—APOE4—were at an increased risk of developing Alzheimer’s if they also had higher DDE levels. The researchers suggested that people with the APOE4 gene may be more susceptible to DDT/DDE exposure. People with the APOE4 gene are already at a higher risk of developing the disease, so adding DDT exposure appears to further add to the risk.

Although DDT was banned decades ago, it persists in the environment for a very long time, and it is not banned in many other countries, so we are still at risk of exposure. “Our results suggest that cumulative lifetime exposures may be important,” stated Jason Richardson, PhD, lead researcher.

Fortunately DDT exposure is decreasing in this country, but we are still somewhat exposed to it and its breakdown products via air, water, and food. This persistent pesticide was banned for good reason, but its negative effects still linger.

Researchers may be able to use this research to later determine whether Alzheimer’s disease can be detected at an earlier stage. I hope that this study leads to more like it that investigate the link between environmental and lifestyle factors that lead to this disease. When we know more about what causes it, we will be better able to prevent it.