Mediterranean Diet Reduces Cognitive Decline | Journal Scan

Study Questions:

Does a Mediterranean dietary pattern reduce age-related cognitive decline?


Consecutive participants from the Barcelona site of the PREDIMED (Prevención con Dieta Mediterránea) nutrition intervention trial (enrolled between October 2003 and December 2009) underwent neuropsychological assessment at inclusion and at the end of the study. Participants were randomly assigned to one of three dietary groups (a Mediterranean diet supplemented with extra virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet). The primary outcome of interest was change in cognitive measures over time. Cognition was measured with a Mini-Mental State Examination, Rey Auditory Verbal Learning Test (RAVLT), Animals Semantic Fluency, Digit Span subtest from the Wechsler Adult Intelligence Scale, Verbal Paired Associates from the Wechsler Memory Scale, and the Color Trail Test. Mean z scores of change in each test were used to group results into three cognitive composite measures of memory, frontal (attention and executive function), and global cognition.


A total of 334 participants had cognitive testing results at entry and end of the study (mean follow-up, 4.1 years). Mean age of the participants was 66.8 years, and 50.9% were women. After adjustment for potential confounders, participants randomized to the Mediterranean diet with olive oil had higher scores on the RAVLT and Color Trail Test compared to the control group. No differences were noted between the three groups for the other cognitive tests. Adjusted composite scores for changes in baseline memory were significantly better than the control group for the Mediterranean diet plus nuts group, 0.09 (−0.05 to 0.23; p = 0.04 vs. controls). Changes in frontal cognition (composite score) were significantly better than controls for the Mediterranean diet plus olive oil group, 0.23 (0.03-0.43; p = 0.003 vs. controls). Changes from baseline for the global cognition composite were significantly improved for the Mediterranean diet plus olive oil group compared to controls, 0.05 (−0.11 to 0.21; p = 0.005 vs. controls). All cognitive composites significantly (p < 0.05) decreased from baseline in controls.


The investigators concluded that in an older population, a Mediterranean diet supplemented with olive oil or nuts is associated with improved cognitive function.


These data add further evidence that supporting a healthy lifestyle may reduce age-related declines in cognitive function.

Clinical Topics: Diabetes and Cardiometabolic Disease, Dyslipidemia, Prevention, Lipid Metabolism, Diet

Keywords: Cognition, Control Groups, Dietary Fats, Diet, Mediterranean, Executive Function, Follow-Up Studies, Food Habits, Intelligence, Life Style, Neuropsychological Tests, Nuts, Plant Oils, Primary Prevention, Semantics, Verbal Learning

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