Older people who followed a Mediterranean diet retained more brain volume over a three-year period than those who did not follow the diet as closely, a new study published in Neurology shows. But contrary to earlier studies, eating more fish and less meat was not related to changes in the brain.

The Mediterranean diet includes large amounts of fruits, vegetables, olive oil, beans and cereal grains such as wheat and rice, moderate amounts of fish, dairy and wine, and limited red meat and poultry.

Researchers gathered information on the eating habits of 967 Scottish people around age 70 who did not have dementia. Of those people, 562 had an MRI brain scan around age 73 to measure overall brain volume, gray matter volume and thickness of the cortex, which is the outer layer of the brain. From that group, 401 people then returned for a second MRI at age 76. These measurements were compared to how closely participants followed the Mediterranean diet.

The participants varied in how closely their dietary habits followed the Mediterranean diet principles. People who didn’t follow as closely to the Mediterranean diet were more likely to have a higher loss of total brain volume over the three years than people who followed the diet more closely. The difference in diet explained 0.5 percent of the variation in total brain volume, an effect that was half the size of that due to normal aging.

The results were the same when researchers adjusted for other factors that could affect brain volume, such as age, education and having diabetes or high blood pressure.

There was no relationship between grey matter volume or cortical thickness and the Mediterranean diet.

Paper: “Mediterranean-type diet and brain structural change from 73 to 76 years in a Scottish cohort”
Reprinted from materials provided by the American Academy of Neurology.

február 15, 2017