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Serum α-linolenic and other ω-3 fatty acids, and risk of disabling dementia: Community-based nested case-control study

Yamagishi K, Ikeda A, Chei CL, Noda H, Umesawa M, Cui R, Muraki I, Ohira T et al.

Clinical nutrition (Edinburgh, Scotland), 2017

7,586 participants · 37 citations

Abstract

BACKGROUND & AIMS: It has been hypothesized that ω-3 polyunsaturated fatty acids have anti-atherosclerotic and neuronal protective functions and may benefit prevention of dementia, but the epidemiological evidence, especially for α-linolenic acid, is quite limited. The aim of this study was to examine whether serum ω-3 polyunsaturated fatty acids are associated with risk of dementia.

METHODS: We performed an intracohort case-control study nested in a community-based cohort, the Circulatory Risk in Communities Study, involving 7586 Japanese individuals aged 40-74 years at the baseline period of 1984-1994. Omega-3 polyunsaturated fatty acid constituents (α-linolenic, eicosapentaenoic, and docosahexaenoic acids) in serum total lipid were measured in 315 cases of incident disabling dementia in the above-mentioned cohort between 1999 and 2004, and in 630 controls whose age, sex, area, and baseline year were matched with the cases.

RESULTS: As we had postulated, serum α-linolenic acid was inversely associated with risk of disabling dementia: the multivariate odds ratios (95% confidence intervals) were 0.57 (0.39-0.85), 0.51 (0.34-0.76), and 0.61 (0.41-0.90) for persons with the second, third, and highest quartiles of serum α-linolenic acid, respectively, as compared with the lowest quartile (P for trend = 0.01). Associations of other ω-3 fatty acids with disabling dementia were not statistically significant.

CONCLUSIONS: Serum α-linolenic acid was inversely associated with risk of…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 7,586 participants or records.

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