Dietary patterns and risk of dementia: The Three-City Cohort study

January 1, 2007 Human Health and Nutrition Data 0 Comments

Dietary patterns and risk of dementia: The Three-City Cohort study

Year: 2007
Authors: Barberger-Gateau, P. Raffaitin, C. Letenneaur, L. Berr, C. Tzourio, C. Dartigues, J.F. Alp�rovitch, A.
Publication Name: Neurology
Publication Details: Volume 69; Pages 1921-1930.


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. 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). 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 ApoE4 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 ApoE4  non-carriers. Frequent consumption of fruits and vegetables, fish, and omega-3 rich oils may decrease the risk of dementia and Alzheimer disease, especially among ApoE 4 non-carriers. (Author's Abstract)
Alzheimer disease (AD) is the most frequent cause of dementia in older persons. The main risk factors of late-onset AD are age and possession of the ApoE 4 allele. Regular fish consumers show a significantly decreased risk of incident dementia over 7 years of follow-up. Antioxidants could enhance the protective effect of omega-3 PUFA by protecting them against peroxidation.  There might be interactions between ApoE genotype and lipid metabolism, since ApoE is involved in the transport of lipids around the body. This study aimed to analyze the relationship between various components of diet rich in fat or antioxidants and risk of dementia or AD in French older persons included in the Three-City (3C) study, adjusting for individual characteristics and taking into account the potential interactions between foods and with the ApoE genotype. This study shows an apparent protective effect of dietary sources of both essential (vegetable oils) and long-chain (fish) omega-3 PUFA against dementia. Conversely, regular consumption of omega-6 rich oils is associated with an increased risk of dementia when not compensated by intake of dietary sources of omega-3 PUFA. No significant interaction between the main sources of antioxidants (fruits and vegetables) and sources of omega-3 PUFA (oils and fish). A more protective effect of fish against AD and among ApoE 4 non-carriers. Alpha-linolenic acid was strongly protective among persons with the ApoE 4 allele  The interaction between dietary fat and ApoE genotype on risk for dementia or AD deserves further research. In this study, a diet rich in fish, omega-3 rich oils, fruits, and vegetables was associated with a lower risk of dementia and AD in older persons whereas consumption of omega-6 rich oils showed detrimental effects when not counterbalanced by sufficient omega-3 intake. These effects were more pronounced among ApoE 4 non-carriers. Given that most individuals are ApoE 4 non-carriers, these results could have considerable implications in terms of public health. Randomized trials  to identify the optimal quantity and combination of these nutrients are encouraged. (Editor's comments)

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