The Mediterranean diet is based on the diets of the populations bordering the Mediterranean Sea, such as Italy and Greece. The diet emphasizes fresh fruits and vegetables, fish, whole grains, legumes, monounsaturated fats like olive oil, and moderate amounts of alcohol. It has a low amount of red meat, saturated fats like butter, and refined grains.
Eating a Mediterranean diet has already been linked to a lower risk of what is called the metabolic syndrome, heart disease, stroke and dementia. However, researchers say no study has looked at the diet's possible link to white matter hyperintensity volume (WMHV) in the brain, which might help explain some of these beneficial effects.
WMHV is an indicator of small blood vessel damage in the brain and is detected by magnetic resonance screening (MRI). WMHV can be found in the average person as he or she ages. Previous studies have shown that high amounts of WMHV in the brain can predict a higher risk of stroke and dementia.
In the study, researchers compared the brain scans and diets of 966 adults with an average age of 72. The participants' reported diets were rated according to how closely they followed a Mediterranean diet.
The results showed that those who most closely followed a Mediterranean diet had a lower measure of WMHV than those who did not. Each increase in the Mediterranean diet score was associated with a corresponding decrease in white matter hyperintensity volume score.
This benefit remained consistent even after adjusting for other risk factors for small blood vessel damage in the brain, like smoking, diabetes, high blood pressure, and abnormal cholesterol levels.
Researchers say the aspect of the Mediterranean diet that seemed to matter most was the ratio of monounsaturated fat to saturated fat.
Monounsaturated fats are found in many vegetable oils, avocados and nuts. Saturated fats are mainly found in meat and dairy products, as well as in some processed foods.
However, researcher Hannah Gardener, ScD, of the University of Miami Miller School of Medicine, and colleagues say their results suggest that "overall dietary pattern, rather than any of the individual components" may be more relevant in explaining the healthy benefits of the Mediterranean diet.
The results appear in the Archives of Neurology.
From the February 14, 2012, Prepared Foods' Daily News.