Dementia is a growing health issue. Studies have shown that modest decrements in cognitive function strongly predict eventual development of dementia
1-3; these early stages of cognitive decline may be most susceptible to intervention. The Physicians' Health Study II (PHSII) is a randomized trial of beta carotene and other vitamin supplements for cardiovascular disease and cancer prevention; cognitive evaluations were added to the trial to assess the cognitive impact of supplementation. Beta carotene, a lipophilic, provitamin A carotenoid, is a potent antioxidant.