Science

Cinta Valls-Pedret, MSc
Aleix Sala-Vila, DPharm, PhD
Mercè Serra-Mir, RD
Dolores Corella, DPharm, PhD
Rafael de la Torre, DPharm, PhD
Miguel Ángel Martínez-González, MD, PhD
Elena H. Martínez-Lapiscina, MD, PhD
Montserrat Fitó, MD, PhD
Ana Pérez-Heras, RD
Jordi Salas-Salvadó, MD, PhD
Ramon Estruch, MD, PhD
Emilio Ros, MD, PhD

Parallel-group randomized clinical trial of 447 cognitively healthy volunteers from Barcelona, Spain (233 women [52.1%]; mean age, 66.9 years), 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. 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). Rates of cognitive change over time based on a neuropsychological test battery: 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. We used mean z scores of change in each test to construct 3 cognitive composites: memory, frontal (attention and executive function), and global.