Last week, we reported that organophosphate pesticide exposure may be linked to an increased risk of attention deficit hyperactivity disorder (ADHD) in children. Now, according to an observational study published in the May issue of the journal Neurology, repeated pesticide exposure is associated with an increased risk for Alzheimer’s disease later in life.

Researchers from Duke University and their colleagues used data from the Cache County Study of Memory Health and Aging to study the effects of repeated occupational pesticide exposure on dementia risk. Cache County is an agricultural community in northern Utah, a setting where routine pesticide use is common and exact pesticide exposure can be verified. The study included individuals aged 65 and older who were followed for an average of 7.2 years. Of the 3,084 individuals who were dementia-free at baseline, 572 reported some pesticide exposure. Pesticide exposure was more common among men than women, and more than 40% of those who reported pesticide exposure were farmers by occupation. Five hundred individuals developed dementia during follow-up, and 108 of these were people who reported pesticide exposure. 

The study authors emphasize that this is an observational study which simply suggests an association between repeated pesticide use and Alzheimer’s disease risk. Further study is needed to determine if there is, in fact, a causal link. At this point, it is too early to recommend avoidance of pesticide use, but individuals who routinely use to pesticides are advised to follow safety instructions and precautions during pesticide exposure.

Source:

Neurology. 2010; 74: 1524-1530.