Agent Orange Associated With Higher Risk for Dementia in Study of Vietnam Vets

A study published in JAMA Neurology suggests Vietnam War veterans who reported being exposed to Agent Orange were twice as likely to receive a dementia diagnosis than non-exposed veterans, reports Neurology Today . The researchers analyzed the health data for 316,351 vets. The vets were almost all men (98 percent) and on average 62 years old at the study's launch. A total of 38,121 participants (12.1 percent) reported a history of exposure to Agent Orange. Following statistical adjustments to account for confounding factors, exposed vets were determined to be 1.68 times more likely to be diagnosed with dementia, and were on average 1.25 years younger at diagnosis — 67.5 years old versus 68.8 years old. These findings do not definitively demonstrate a cause-and-effect mechanism between Agent Orange and dementia risk, or specify a possible biological mode of action. University of California, San Francisco Professor Deborah Barnes suggested Agent Orange's chemical ingredient dioxin could be having an effect. "Dioxin could have a direct toxic effect on the brain or could act indirectly by impairing blood circulation or increasing the risk of other diseases that, in turn, increase dementia risk," she said.