May 24, 2011
Nutrition scientists continue to extol the virtues of a Mediterranean diet, the traditional diet from Italy, Greece and other countries that border the Mediterranean Sea. The diet, high in fruits and vegetables and healthy fats like olive oil, along with modest amounts of red wine and little red meat, may curb heart disease and prolong life – and keep your mind sharp and free of Alzheimer’s disease in old age, studies suggest.
Now a large new study from Rush Medical College in Chicago provides the strongest evidence to date that a Mediterranean style diet may be good for the brain. Researchers studied 3,790 men and women ages 65 and older, tracking them over many years beginning in 1993. They were given regular questionnaires about the foods they ate, along with tests of memory and thinking skills every three years.
Those seniors who adhered to a Mediterranean diet most strictly scored higher on mental acuity and memory tests than those who didn’t eat much of the heart-healthy foods. Overall, those who stuck most closely to a Mediterranean diet were two years younger in “brain age” than their peers who didn’t follow such a diet. The findings held even after adjusting for risk factors like age, sex, race, years of education and participation in mentally stimulating activities.
The researchers caution that they could not account for all the many factors that may contribute to cognitive decline in old age. Food surveys, in which people fill out what they eat, can be unreliable, though the researchers used scientifically validated methods to analyze the results, and the study involved a large number of people.
The findings, which appeared in the American Journal of Clinical Nutrition, bolster a growing body of evidence that a heart-healthy Mediterranean diet is good for the brain. Earlier, smaller studies have reported that healthy people who follow a Mediterranean diet lower their risk of developing Alzheimer’s disease. And those with Alzheimer’s who followed such a diet lived longer than their peers who did not. Earlier research has also shown that a Mediterranean diet may cut the risk of strokes, cancer, diabetes and possibly other illnesses as well.
Doctors are not sure why a Mediterranean diet may be good for the brain. One possibility is that such a diet reduces a risk for blood vessel disease, which may contribute to the risk for Alzheimer’s disease. A Mediterranean diet helps cut down on inflammatory substances in the body, too, and inflammation has increasingly been tied to heart disease and possibly Alzheimer’s as well. Fruits, vegetables and red wine are also high in cell-protecting antioxidants.
Key components of the Mediterranean diet include:
- An abundance of fiber-rich fruits, vegetables, cereals, nuts and beans;
- Choosing “good” fats like olive or canola oil, rather than butter or lard, and limiting dairy products like high-fat cheese and milk;
- Eating moderate amounts of fish and poultry, rather than red meat; and
- Drinking a glass or two of red wine a day.
Many other factors besides diet, including the genes you inherit and advancing age, play an important role in who ultimately develops Alzheimer’s. Still, the findings suggest that lifestyle factors can have an impact on Alzheimer’s risk. Eating a heart-healthy diet, along with getting regular exercise and keeping weight down, may help keep the brain young.
Source: Tangney CC, Kwasny MJ, Li H, Wilson RS, Evans DA, Morris MC: “Adherence to a Mediterranean-type dietary pattern and cognitive decline in a community population.” American Journal of Clinical Nutrition, Dec. 22, 2010.