title: Virgin olive oil supplementation and long-term cognition: the PREDIMED-NAVARRA randomized, trial.
abstract: OBJECTIVE
  To assess the effect on cognition of a controlled intervention testing Mediterranean diets (MedDiet).
  
  
  METHODS
  Randomized trial after 6.5 years of nutritional intervention.
  
  
  METHODS
  Eight primary care centers affiliated to the University of Navarra.
  
  
  METHODS
  A random subsample of 285 participants (95 randomly allocated to each of 3 groups) of the PREDIMED-NAVARRA trial. All of them were at high vascular risk (44.8% men, 74.1±5.7 years at cognitive evaluation).
  
  
  METHODS
  Nutritional intervention comparing two MedDiets (supplemented with extra-virgin olive oil [EVOO] or mixed nuts) versus a low-fat control diet. Participants received intensive education to increase adherence to the intended intervention. Participants allocated to the MedDiet groups received EVOO (1 l/week) or 30 g/day of mixed nuts. Dietary habits were evaluated using a validated 137-item food frequency questionnaire (FFQ). Additionally, adherence to MedDiet was appraised using a 14-item questionnaire both at baseline and yearly thereafter.
  
  
  METHODS
  Cognitive performance as a main outcome and cognitive status (normal, mild cognitive impairment [MCI] or dementia) as a secondary outcome were evaluated by two neurologists blinded to group assignment after 6.5 years of nutritional intervention.
  
  
  RESULTS
  Better post-trial cognitive performance versus control in all cognitive domains and significantly better performance across fluency and memory tasks were observed for participants allocated to the MedDiet+EVOO group. After adjustment for sex, age, education, apolipoprotein E genotype, family history of cognitive impairment/dementia, smoking, physical activity, body mass index, hypertension, dyslipidaemia, diabetes, alcohol and total energy intake, this group also showed lower MCI (OR=0.34 95% CI: 0.12-0.97) compared with control group. Participants assigned to MedDiet+Nuts group did not differ from controls.
  
  
  CONCLUSIONS
  A long-term intervention with an EVOO-rich MedDiet resulted in a better cognitive function in comparison with a control diet. However, non-significant differences were found for most cognitive domains. Participants allocated to an EVOO-rich MedDiet had less MCI than controls.
authors.affiliation: Departamento de Medicina Preventiva y Salud Pública, Facultad de Medicina-Clínica Universidad de Navarra, Universidad de Navarra, C/ Irunlarrea n1 1, Pamplona, Navarra, E-31008, Spain. elenahmlapiscina@gmail.com
authors.forename: E H
authors.initials: EH
authors.lastname: Martínez-Lapiscina
authors.forename: P
authors.initials: P
authors.lastname: Clavero
authors.forename: E
authors.initials: E
authors.lastname: Toledo
authors.forename: B
authors.initials: B
authors.lastname: San Julián
authors.forename: A
authors.initials: A
authors.lastname: Sanchez-Tainta
authors.forename: D
authors.initials: D
authors.lastname: Corella
authors.forename: R M
authors.initials: RM
authors.lastname: Lamuela-Raventós
authors.forename: J A
authors.initials: JA
authors.lastname: Martínez
authors.forename: M Á
authors.initials: MÁ
authors.lastname: Martínez-Gonzalez
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D003071:Cognition / Q000187:drug effects*; D060825:Cognitive Dysfunction / Q000178:diet therapy; D003704:Dementia / Q000178:diet therapy; D018752:Diet, Fat-Restricted; D038441:Diet, Mediterranean; D019587:Dietary Supplements; D002149:Energy Intake; D005247:Feeding Behavior; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D015999:Multivariate Analysis; D015596:Nutrition Assessment; D009754:Nuts; D000069463:Olive Oil; D010349:Patient Compliance; D010938:Plant Oils / Q000008:administration & dosage*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D000069463:Olive Oil; D010938:Plant Oils