Adherence to a Mediterranean diet, cognitive decline, and risk of dementia.
BACKGROUND
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.


METHODS
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.


METHODS
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.
Féart
Catherine
C
Research Center INSERM U897, Université Victor Segalen Bordeaux 2, Bordeaux, France. catherine.feart@isped.u-bordeaux2.fr
Samieri
Cécilia
C
Rondeau
Virginie
V
Amieva
Hélène
H
Portet
Florence
F
Dartigues
Jean-François
JF
Scarmeas
Nikolaos
N
Barberger-Gateau
Pascale
P
D000368:Aged; D000369:Aged, 80 and over; D001057:Apolipoproteins E / Q000235:genetics; D015992:Body Mass Index; D003071:Cognition; D003072:Cognition Disorders / Q000150:complications / Q000453:epidemiology* / Q000517:prevention & control; D015986:Confounding Factors, Epidemiologic; D003704:Dementia / Q000453:epidemiology* / Q000209:etiology; D003863:Depression; D038441:Diet, Mediterranean; D004522:Educational Status; D002149:Energy Intake; D005260:Female; D005602:France / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D008297:Male; D017533:Marital Status; D009483:Neuropsychological Tests; D016017:Odds Ratio; D011322:Primary Prevention / Q000379:methods; D011446:Prospective Studies; D012107:Research Design; D012111:Residence Characteristics; D012307:Risk Factors
D001057:Apolipoproteins E