According to the results of a study published in the Annals of Neurology, Americans who ate Mediterranean diet had reduced risks of developing Alzheimer's disease. Based on dietary data from a community-based survey, researchers found out that depending on how religious the test subjects adhered to the Mediterranean diet, the risk for contracting Alzheimer's diseaed dropped by 15 to 40%.

Compared with the subjects in the least adherent group that adhered to a Mediterranean diet the least, subjects in the middle tertile had 15 to 21 percent lower risk of developing Alzheimer's disease, and those in the highest tertile had a 39 to 40 percent lower risk, suggesting a significant dose response effect. The association remained significant even after adjusting for potential confounders such as age, gender, ethnicity, education, caloric intake, BMI, smoking and comorbid conditions.

One characteristic of the Mediterranean diet that imparts such benefit may be the antioxidative properties of the food that comprise such a diet: fruits, vegetables, legumes, cereals, herbs, some fish and alcohol. Dairy and meat comprise just a small fraction of the diet.