By Dr Ananya Mandal, MD
A new study suggests that people who follow a Mediterranean-style diet have less small blood vessel damage in the brain. The study appeared in the February issue of the Archives of Neurology.
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's called the metabolic syndrome, heart disease, stroke, and dementia.
But 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.
Hannah Gardener, from the University of Miami, and colleagues administered a semi quantitative food frequency questionnaire to 966 participants (mean age, 72 years; 59.3 percent women; 64.6 percent Hispanic, 15.6 percent white, and 17.5 percent black) from the Northern Manhattan Study. The survey was scored (range, 0 to 9) to reflect increasing similarity to the MeDi pattern. Quantitative brain magnetic resonance imaging was used to assess white matter hyperintensity volume.
They found that 11.6 percent of participants scored 0 to 2 on the Mediterranean diet scale; 15.8 percent scored 3; 23.0 percent scored 4; 23.5 percent scored 5; and 26.1 percent scored 6 to 9. There was a significantly lower log white matter hyperintensity volume for each one-point increase in the Mediterranean diet score. The ratio of monounsaturated to saturated fat was the only component of the Mediterranean diet score that independently predicted white matter hyperintensity volume.
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.