Adherence to a Mediterranean Diet, Cognitive Decline, and Risk of Dementia

JAMA. 2009 Aug 12;302(6):638-48. doi: 10.1001/jama.2009.1146.

Abstract

Context: Higher adherence to a Mediterranean-type diet is linked to lower risk for mortality and chronic diseases, but its association with cognitive decline is unclear.

Objective: To investigate the association of a Mediterranean diet with change in cognitive performance and risk for dementia in elderly French persons.

Design, setting, and participants: Prospective cohort study of 1410 adults (> or = 65 years) from Bordeaux, France, included in the Three-City cohort in 2001-2002 and reexamined at least once over 5 years. Adherence to a Mediterranean diet (scored as 0 to 9) was computed from a food frequency questionnaire and 24-hour recall.

Main outcome measures: Cognitive performance was assessed on 4 neuropsychological tests: the Mini-Mental State Examination (MMSE), Isaacs Set Test (IST), Benton Visual Retention Test (BVRT), and Free and Cued Selective Reminding Test (FCSRT). Incident cases of dementia (n = 99) were validated by an independent expert committee of neurologists.

Results: Adjusting for age, sex, education, marital status, energy intake, physical activity, depressive symptomatology, taking 5 medications/d or more, apolipoprotein E genotype, cardiovascular risk factors, and stroke, higher Mediterranean diet score was associated with fewer MMSE errors (beta = -0.006; 95% confidence interval [CI], -0.01 to -0.0003; P = .04 for 1 point of the Mediterranean diet score). Performance on the IST, BVRT, or FCSRT over time was not significantly associated with Mediterranean diet adherence. Greater adherence as a categorical variable (score 6-9) was not significantly associated with fewer MMSE errors and better FCSRT scores in the entire cohort, but among individuals who remained free from dementia over 5 years, the association for the highest compared with the lowest group was significant (adjusted for all factors, for MMSE: beta = -0.03; 95% CI, -0.05 to -0.001; P = .04; for FCSRT: beta = 0.21; 95% CI, 0.008 to 0.41; P =.04). Mediterranean diet adherence was not associated with the risk for incident dementia (fully adjusted model: hazard ratio, 1.12; 95% CI, 0.60 to 2.10; P = .72), although power to detect a difference was limited.

Conclusions: Higher adherence to a Mediterranean diet was associated with slower MMSE cognitive decline but not consistently with other cognitive tests. Higher adherence was not associated with risk for incident dementia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Apolipoproteins E / genetics
  • Body Mass Index
  • Cognition Disorders / complications
  • Cognition Disorders / epidemiology*
  • Cognition Disorders / prevention & control
  • Cognition*
  • Confounding Factors, Epidemiologic
  • Dementia / epidemiology*
  • Dementia / etiology
  • Depression
  • Diet, Mediterranean*
  • Educational Status
  • Energy Intake
  • Female
  • France / epidemiology
  • Genotype
  • Humans
  • Male
  • Marital Status
  • Neuropsychological Tests
  • Odds Ratio
  • Primary Prevention / methods
  • Prospective Studies
  • Research Design
  • Residence Characteristics
  • Risk Factors

Substances

  • Apolipoproteins E