An ongoing study has shown that following a Mediterranean-style diet can reduce the risk of cognitive decline with older age.

The Chicago Health and Aging Project includes nearly 4,000 adults aged 65 and older.

Participants were given a battery of cognitive tests that were assigned scores and then took part in a clinical interview. Those who ranked in the highest in terms of following such a Mediterranean-type diet were more protected from cognitive decline. The adults were given these cognitive tests every three years for 15 years.

"This diet emphasizes vegetables, fruits, fish, olive oil, lower meat consumption, and moderate wine and non-refined grain intake," said lead author Dr. Christy Tangney of Rush University Medical Center in Chicago. "Instead of espousing avoidance of foods, the data support that adults over age 65 should look to include more olive oil, legumes, nuts, and seeds in their diet in order to improve their recall times and other cognitive skills, such as identifying symbols and numbers."

Tangney also added that physical activity is also important to avoid cognitive problems.

The Mediterranean diet is also believed to improve heart health.