Virgin Olive Oil Supplementation and Long-Term Cognition: The PREDIMED-NAVARRA Randomized, Trial

J Nutr Health Aging. 2013;17(6):544-52. doi: 10.1007/s12603-013-0027-6.

Abstract

Objective: To assess the effect on cognition of a controlled intervention testing Mediterranean diets (MedDiet).

Design: Randomized trial after 6.5 years of nutritional intervention.

Setting: Eight primary care centers affiliated to the University of Navarra.

Participants: 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).

Interventions: 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.

Measurements: 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.

Conclusion: 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.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Aged, 80 and over
  • Body Mass Index
  • Cognition / drug effects*
  • Cognitive Dysfunction / diet therapy
  • Dementia / diet therapy
  • Diet, Fat-Restricted
  • Diet, Mediterranean
  • Dietary Supplements*
  • Energy Intake
  • Feeding Behavior
  • Female
  • Follow-Up Studies
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Motor Activity
  • Multivariate Analysis
  • Nutrition Assessment
  • Nuts
  • Olive Oil
  • Patient Compliance
  • Plant Oils / administration & dosage*
  • Surveys and Questionnaires
  • Treatment Outcome

Substances

  • Olive Oil
  • Plant Oils

Associated data

  • ISRCTN/ISRCTN35739639