Mediterranean Diet and Age-Related Cognitive Decline: A Randomized Clinical Trial

Original Publication: JAMA Internal Medicine
Published: 1 July 2015

Emerging evidence suggests an association between dietary habits and cognitive performance. Oxidative stress has long been considered to play a major role in cognitive decline and neurodegenerative disorders.8 Thus, it is plausible that, by counteracting oxidative stress, antioxidant-rich foods might afford protection from neurodegenerative diseases. The Mediterranean diet is a plant-based, antioxidant-rich dietary pattern reputed for its many health benefits. As previously reviewed, data from large observational studies suggest that increasing adherence to Mediterranean-type diets relates to better cognitive function and a reduced risk of dementia.

Study Recommendation

In an older population, a Mediterranean diet which limits unhealthy fats, and is rich in antioxidant foods such as fruits, vegetables, fish and whole grains, supplemented with olive oil or nuts is associated with improved cognitive function.

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Study Details

Parallel-group randomized clinical trial of 447 cognitively healthy volunteers from Barcelona, Spain at high cardiovascular risk were enrolled into the Prevención con Dieta Mediterránea nutrition intervention trial from October 1, 2003, through December 31, 2009. All patients underwent neuropsychological assessment at inclusion and were offered retesting at the end of the study. Interventions Participants were randomly assigned to a Mediterranean diet supplemented with extra virgin olive oil (1 L/wk), a Mediterranean diet supplemented with mixed nuts (30 g/d), or a control diet (advice to reduce dietary fat).

Contact Information

Emilio Ros, MD, PhD, Lipid Clinic, Endocrinology and Nutrition Service, Hospital Clínic, Villarroel 170, 08036 Barcelona, Spain (


Valls-Pedret C, Sala-Vila A, Serra-Mir M, et al. Mediterranean Diet and Age-Related Cognitive Decline: A Randomized Clinical Trial. JAMA Intern Med. 2015;175(7):1094-1103. doi:10.1001/jamainternmed.2015.1668.


Emilio Ros, MD, PhD,

Original source: