Mediterranean diet may help prevent Alzheimer's

Researchers at the National Eye Institute (NEI), part of the National Institutes of Health, found that people who follow a Mediterranean diet (rich in vegetables, whole grains, fish, and olive oil) have better cognitive function. The Mediterranean diet can also slow cognitive decline. They published their findings in the journal Alzheimer's & Dementia.

The researchers studied the effects of nine components of the Mediterranean diet - high in fruits, vegetables, whole grains, nuts, legumes, fish and olive oil, and low in red meat and alcohol - on cognition.

The AREDS study and AREDS2 study were originally vitamins for age-related macular degeneration (AMD), and involved about 4,000 participants with and without AMD. The AREDS study tested participants' cognitive function over a five-year period, while AREDS2 tested participants' cognitive function at baseline and after two, four, and 10 years. They used questionnaires to ask about their average dietary intake over the past year.

Results showed that participants who adhered most to the Mediterranean diet had the lowest risk of cognitive impairment. Eating a lot of fish and vegetables had the greatest protective effect. Participants in the AREDS2 study with the highest fish consumption had the slowest rate of cognitive decline after 10 years.