Two Foods to Boost Cognition

Oxidative stress and vascular impairment are thought to play key roles in cognitive decline. Epidemiologic studies suggest that eating an antioxidant-rich, cardioprotective Mediterranean diet may help to slow cognitive decline, however clinical trial evidence to support this has been lacking. To address this, Emilio Ros, MD, PhD, of the Department of Endocrinology and Nutrition, Institut d'Investigacions Biomèdiques August Pi Sunyer (Barcelona, Spain), conducted a randomized clinical trial of 447 cognitively healthy (but at high cardiovascular risk) volunteers, from Barcelona, Spain (mean age 66.9 years). Participants were randomly assigned to a Mediterranean diet supplemented with 1 litre a week of extra virgin olive oil, a Mediterranean diet supplemented with 30 g/day of mixed nuts (walnuts, hazelnuts, and almonds), or a control diet (advice to reduce dietary fat). Results showed that participants assigned to the low-fat control diet had a significant decrease from baseline in all aspects of cognitive function. Whereas memory improved significantly in the Mediterranean diet plus nuts group, and frontal and global cognition improved in the Mediterranean diet plus olive oil group. The authors concluded: "Our results suggest that in an older population a Mediterranean diet supplemented with olive oil or nuts may counteract age-related cognitive decline. The lack of effective treatments for cognitive decline and dementia points to the need of preventive strategies to delay the onset and/or minimize the effects of these devastating conditions. The present results with the Mediterranean diet are encouraging but further investigation is warranted."