Mediterranean Diet Might Reduce Alzheimer's Risk

Initial findings from a new study conducted by researchers at the Columbia University Medical Center, New York, show that following a Mediterranean-style diet might play a part in reducing risk for Alzheimer's disease. The research was led by Dr. Nikolaos Scarmeas, assistant professor of neurology, Columbia University, New York, and funded in part by the National Institute on Aging, one of the National Institutes of Health. The results of the study were published online in the Annals of Neurology online on April 18.

Previous research has shown that the Mediterranean diet might help reduce the risk of heart disease. However, those studies tended to focus on individual foods or nutrients, like fish or vitamin C, notes Scarmeas. He explains that by studying a comprehensive diet, this new research might permit conclusions that arise from potential interactions between specific foods and nutrients. The Mediterranean diet focuses on vegetables, legumes, fruits, cereals and fish, with limited consumption of meat and dairy products. It also includes moderate alcohol intake--primarily wine with meals--and emphasizes monounsaturated fats like olive oil.

The 2,258 subjects involved in this community-based study were all part of the ongoing Washington Heights-Inwood Columbia Aging Project, a population-based epidemiological investigation of Alzheimer's disease and related disorders led by Dr. Richard Mayeux, professor of neurology, psychiatry and epidemiology, director of the Gertrude H. Sergievsky Center, and co-director of the Taub Institute of Research on Alzheimer's Disease and the Aging Brain, Columbia University. At the beginning of the study, among other exams and screenings, each subject was tested for dementia. Alzheimer's disease is a common cause of dementia and one of the top-10 causes of death in the United States, according to the Centers for Disease Control and Prevention. Researchers evaluated study participants every 1.5 years. After 4 years, 262 subjects had been diagnosed with Alzheimer's disease.

Researchers devised a scale, from zero to nine, to indicate each individual's relative adherence to a Mediterranean-style diet. In the published findings, Scarmeas et al. note that participants who had a higher tendency toward following the diet showed a significantly lower risk--up to 40%--of developing Alzheimer's disease. They note that this association remained significant even when other factors, including age, gender, ethnicity, education, caloric intake, body-mass index, smoking and any preexisting diseases or conditions, were taken into consideration. For each point higher an individual scored on the scale, their risk for developing Alzheimer's disease dropped by about 10%.

The researchers note that the anti-inflammatory and antioxidant properties of some of the Mediterranean diet's components, which can contribute to lower incidences of cardiovascular diseases, might have a causal relationship with the resultant reduction of Alzheimer's disease risk.