In an article published online in advance of print in the Annals of Neurology researchers funded in part by the National Institutes on Aging reported an association between consuming a Mediterranean diet and having a lower risk of developing Alzheimer's disease. The Mediterranean diet contains high amounts of fruits, vegetables, legumes and grains, some fish and alcohol, and less meat and dairy products. Recent research has revealed a lower risk of cardiovascular disease and certain cancers associated with this pattern of eating.

Nikolaos Scarmeas of Columbia University Medical Center and his New York team conducted the current study of 2,258 men and women enrolled in the Washington Heights-Inward Columbia Aging project. Participants were free of dementia at the beginning of the study, and were followed for an average of four years. Medical and neurological histories were obtained, and physical and neurological examinations were conducted at the beginning of the study and every 18 months to determine whether dementia had developed. Dietary questionnaires completed by the participants were evaluated to determined how closely the subjects followed a Mediterranean diet, and participants were scored from 0 to 9 according to their adherence.

Two hundred sixty-two subjects were diagnosed with Alzheimer's disease over the follow-up period. Subjects whose diet adherence scores were among the top third of participants had a 40 percent lower risk of developing Alzheimer's disease than those in the lowest third, while those whose scores fell in the middle third experienced a 15 percent lower risk. The response to the diet appeared to be dose-dependent, with each Mediterranean diet score point associated with a reduction in Alzheimer's disease risk of 9 to 10 percent.

"We conclude that higher adherence to the Mediterranean diet is associated with a reduction in risk for Alzheimer's disease," the authors write.