title: Mediterranean Diet and Age-Related Cognitive Decline: A Randomized Clinical Trial.
abstract: OBJECTIVE
  Oxidative stress and vascular impairment are believed to partly mediate age-related cognitive decline, a strong risk factor for development of dementia. Epidemiologic studies suggest that a Mediterranean diet, an antioxidant-rich cardioprotective dietary pattern, delays cognitive decline, but clinical trial evidence is lacking.
  
  
  OBJECTIVE
  To investigate whether a Mediterranean diet supplemented with antioxidant-rich foods influences cognitive function compared with a control diet.
  
  
  METHODS
  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.
  
  
  METHODS
  Participants were randomly assigned to a Mediterranean diet supplemented with extravirgin olive oil (1 L/wk), a Mediterranean diet supplemented with mixed nuts (30 g/d), or a control diet (advice to reduce dietary fat).
  
  
  METHODS
  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.
  
  
  RESULTS
  Follow-up cognitive tests were available in 334 participants after intervention (median, 4.1 years). In multivariate analyses adjusted for confounders, participants allocated to a Mediterranean diet plus olive oil scored better on the RAVLT (P = .049) and Color Trail Test part 2 (P = .04) compared with controls; no between-group differences were observed for the other cognitive tests. Similarly adjusted cognitive composites (mean z scores with 95% CIs) for changes above baseline of the memory composite were 0.04 (-0.09 to 0.18) for the Mediterranean diet plus olive oil, 0.09 (-0.05 to 0.23; P = .04 vs controls) for the Mediterranean diet plus nuts, and -0.17 (-0.32 to -0.01) for the control diet. Respective changes from baseline of the frontal cognition composite were 0.23 (0.03 to 0.43; P = .003 vs controls), 0.03 (-0.25 to 0.31), and -0.33 (-0.57 to -0.09). Changes from baseline of the global cognition composite were 0.05 (-0.11 to 0.21; P = .005 vs controls) for the Mediterranean diet plus olive oil, -0.05 (-0.27 to 0.18) for the Mediterranean diet plus nuts, and -0.38 (-0.57 to -0.18) for the control diet. All cognitive composites significantly (P < .05) decreased from baseline in controls.
  
  
  CONCLUSIONS
  In an older population, a Mediterranean diet supplemented with olive oil or nuts is associated with improved cognitive function.
  
  
  BACKGROUND
  isrctn.org Identifier: ISRCTN35739639.
authors.affiliation: Lipid Clinic, Department of Endocrinology and Nutrition, Institut d'Investigacions Biomèdiques August Pi Sunyer, Hospital Clínic, Barcelona, Spain.|Ciber Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Cinta
authors.initials: C
authors.lastname: Valls-Pedret
authors.affiliation: Lipid Clinic, Department of Endocrinology and Nutrition, Institut d'Investigacions Biomèdiques August Pi Sunyer, Hospital Clínic, Barcelona, Spain.|Ciber Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Aleix
authors.initials: A
authors.lastname: Sala-Vila
authors.affiliation: Lipid Clinic, Department of Endocrinology and Nutrition, Institut d'Investigacions Biomèdiques August Pi Sunyer, Hospital Clínic, Barcelona, Spain.|Ciber Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Mercè
authors.initials: M
authors.lastname: Serra-Mir
authors.affiliation: Ciber Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Department of Preventive Medicine, University of Valencia, Valencia, Spain.
authors.forename: Dolores
authors.initials: D
authors.lastname: Corella
authors.affiliation: Ciber Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Cardiovascular and Nutrition Research Group, Institut de Recerca Hospital del Mar, Barcelona, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: de la Torre
authors.affiliation: Ciber Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Pamplona, Spain.
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Martínez-González
authors.affiliation: Ciber Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Department of Preventive Medicine and Public Health, School of Medicine, University of Navarra, Pamplona, Spain.
authors.forename: Elena H
authors.initials: EH
authors.lastname: Martínez-Lapiscina
authors.affiliation: Ciber Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Cardiovascular and Nutrition Research Group, Institut de Recerca Hospital del Mar, Barcelona, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Fitó
authors.affiliation: Lipid Clinic, Department of Endocrinology and Nutrition, Institut d'Investigacions Biomèdiques August Pi Sunyer, Hospital Clínic, Barcelona, Spain.|Ciber Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Pérez-Heras
authors.affiliation: Ciber Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Human Nutrition Department, Hospital Universitari Sant Joan, Institut d'Investigació Sanitaria Pere Virgili, Universitat Rovira i Virgili, Reus, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Salas-Salvadó
authors.affiliation: Ciber Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.|Department of Internal Medicine, Institut d'Investigacions Biomèdiques August Pi Sunyer, Hospital Clínic, Barcelona, Spain.
authors.forename: Ramon
authors.initials: R
authors.lastname: Estruch
authors.affiliation: Lipid Clinic, Department of Endocrinology and Nutrition, Institut d'Investigacions Biomèdiques August Pi Sunyer, Hospital Clínic, Barcelona, Spain.|Ciber Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Ros
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition; D003072:Cognition Disorders / Q000178:diet therapy* / Q000517:prevention & control*; D038441:Diet, Mediterranean; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests