A diet highlighting fruits, vegetables, olive oil, beans and cereal grains such as wheat and rice helps older adults maintain brain health, according to the results of a study published in the Jan. 4 online issue of the journal Neurology.

The so-called Mediterranean diet also includes moderate amounts of fish, dairy and wine, as well as limited red meat and poultry. Contrary to earlier studies, the authors of this paper found that eating more fish and less meat was not related to changes in the brain.

Specifically, the researchers discovered that seniors who followed a Mediterranean diet retained more brain volume over a three-year period than those who did not follow the diet as closely. That’s important, said study author Michelle Luciano, Ph.D., of the University of Edinburgh in Scotland, because the brain typically shrinks as people age, which can affect learning and memory.

Researchers studied the eating habits of 967 Scottish people who were aged approximately 70 years and did not have dementia. They measured overall brain volume via brain scan.

Study participants who did not follow as closely to the Mediterranean diet were more likely to have a higher loss of total brain volume over the study’s three years than people who followed the diet more closely. The difference in diet explained 0.5% 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 hypertension.

“In our study, eating habits were measured before brain volume was, which suggests that the diet may be able to provide long-term protection to the brain,” Luciano said. “Still, larger studies are needed to confirm these results.”