A study investigated how diet and physical activity together affected the risk of Alzheimer's disease. The prospective cohort study involved 1,880 community-based elderly subjects, all of whom were dementia free at the study's onset. Participants provided information on their diets and activity levels, and they underwent neurologic evaluations every 1.5 years over a 14-year time span. Variables such as age, sex, education, and smoking status were adjusted for in the statistical analysis.

The study's primary end point was the time to the disease. After a mean of 5.4 years of follow-up, 282 participants developed the disease. Significant associations were found between incidence of Alzheimer's disease and both levels of physical activity and adherence to the Mediterranean diet; further, a significant additive effect was found when they were considered together. A high level of compliance with a Mediterranean diet was associated with a reduction in the risk of Alzheimer's disease of 32% to 40%. High levels of physical activity were associated with a 33%-to-48% lower risk of Alzheimer's disease, as compared with no activity. The study's results bolster evidence that a Mediterranean-type diet combined with greater amounts of physical activity can play an important role in reducing the risk of Alzheimer's disease.

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