Dietary patterns and risk of dementia

TLDR

Dietary fatty acids and antioxidants may lower dementia risk, yet epidemiologic evidence remains inconsistent. This study examined how dietary patterns influence the risk of dementia or Alzheimer disease while controlling for sociodemographic, vascular factors, and ApoE genotype. Using the Three‑City cohort, 8,085 nondemented adults aged 65+ were followed for four years, during which 281 incident dementia cases were neurologically confirmed. Daily fruit and vegetable intake was linked to a 28 % lower risk of all‑cause dementia, weekly fish consumption reduced Alzheimer disease risk by 35 % and all‑cause dementia among ApoE ε4 noncarriers, omega‑3 oil use showed a borderline protective effect, whereas unbalanced omega‑6 intake increased dementia risk by 112 % in noncarriers, indicating that frequent consumption of fruits, vegetables, fish, and omega‑3 oils may lower dementia risk, especially in ApoE ε4 noncarriers. Abbreviations used include AD, BMI, CCPPRB, DHA, EI, HR, and PUFA.

Abstract

<b>Background: </b> Dietary fatty acids and antioxidants may contribute to decrease dementia risk, but epidemiologic data remain controversial. The aim of our study was to analyze the relationship between dietary patterns and risk of dementia or Alzheimer disease (AD), adjusting for sociodemographic and vascular risk factors, and taking into account the ApoE genotype. <b>Methods: </b> A total of 8,085 nondemented participants aged 65 and over were included in the Three-City cohort study in Bordeaux, Dijon, and Montpellier (France) in 1999–2000 and had at least one re-examination over 4 years (rate of follow-up 89.1%). An independent committee of neurologists validated 281 incident cases of dementia (including 183 AD). <b>Results: </b> Daily consumption of fruits and vegetables was associated with a decreased risk of all cause dementia (hazard ratio [HR] 0.72, 95% CI 0.53 to 0.97) in fully adjusted models. Weekly consumption of fish was associated with a reduced risk of AD (HR 0.65, 95% CI 0.43 to 0.994) and all cause dementia but only among ApoE ε4 noncarriers (HR 0.60, 95% CI 0.40 to 0.90). Regular use of omega-3 rich oils was associated with a decreased risk of borderline significance for all cause dementia (HR 0.46, 95% CI 0.19 to 1.11). Regular consumption of omega-6 rich oils not compensated by consumption of omega-3 rich oils or fish was associated with an increased risk of dementia (HR 2.12, 95% CI 1.30 to 3.46) among ApoE ε4 noncarriers. <b>Conclusion: </b> Frequent consumption of fruits and vegetables, fish, and omega-3 rich oils may decrease the risk of dementia and Alzheimer disease, especially among ApoE ε4 noncarriers. <b>GLOSSARY: </b><b>AD</b> = Alzheimer disease; <b>BMI</b> = body mass index; <b>CCPPRB</b> = Consultative Committee for the Protection of Persons participating in Biomedical Research; <b>DHA</b> = docosahexaenoic acid; <b>EI</b> = energy intake; <b>HR</b> = hazard ratio; <b>PUFA</b> = polyunsaturated fatty acids.