A new review indicates more of the benefits of eating a Mediterranean-style diet, one rich in fish, beans, olive oil, nuts, fruit and vegetables.

The first systematic review of related research confirms a positive impact on cognitive function, but an inconsistent effect on mild cognitive impairment.

A team analyzed 12 eligible pieces of research, 11 observational studies and one randomized control trial. In nine out of the 12 studies, a higher adherence to a Mediterranean diet was associated with better cognitive function, lower rates of cognitive decline and a reduced risk of Alzheimer’s disease.

“Mediterranean food is both delicious and nutritious, and our systematic review shows it may help to protect the ageing brain by reducing the risk of dementia,” said lead researcher Iliana Lourida. “While the link between adherence to a Mediterranean diet and dementia risk is not new, ours is the first study to systematically analyze all existing evidence.”

Related article: Mediterranean Diet Boosts Brain Power in Aging Adults