Their grey matter volume was 5 millilitres greater, and their white matter 6.4 millilitres greater, than those who had not stuck to Mediterranean foods.
A Mediterranean diet could help you lose fewer brain cells as you age, a new study has claimed.
Eating lots of fish and vegetables may help prevent your brain shrinking for as long as five years, it says.
People who follow such a diet, which also involves consuming less meat and dairy products than average, end up with bigger brains as the ageing process is slowed down, The Guardian reports.
"These results are exciting, as they raise the possibility that people may potentially prevent brain shrinking and the effects of ageing on the brain simply by following a healthy diet," said the lead author, Yian Gu, of Columbia University in New York.
Bigger brain volume
Researchers looked at 674 people with an average age of 80 who lived in northern Manhattan and did not have dementia.
They found that the total brain volume of those who had closely followed a Mediterranean-style diet was on average 13.11 millilitres greater than that of those who had not done so.
The difference between the two groups is equivalent to about five years of ageing, the authors said.
The Mediterranean diet typically consists of large amounts of vegetables, pulses, fruit, cereal, fish and monounsaturated fatty acids such as olive oil. It also includes small amounts of meat, poultry, dairy products and saturated fatty acids, plus mild to moderate alcohol consumption.