The Relationship of Omega-3 Fatty Acids with Dementia and Cognitive Decline: Evidence from Prospective Cohort Studies of Supplementation, Dietary Intake, and Blood Markers

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#humans #aged #alzheimer-disease #prospective-studies #docosahexaenoic-acids

The Relationship of Omega-3 Fatty Acids with Dementia and Cognitive Decline: Evidence from Prospective Cohort Studies of Supplementation, Dietary Intake, and Blood Markers

Wei et al., 2023 | Am J Clin Nutr | Meta Analysis

Citation

Wei Bao-Zhen, Li Lin, ... Xu Wei. The Relationship of Omega-3 Fatty Acids with Dementia and Cognitive Decline: Evidence from Prospective Cohort Studies of Supplementation, Dietary Intake, and Blood Markers. Am J Clin Nutr. 2023-Jun;117(6):1096-1109. doi:10.1016/j.ajcnut.2023.04.001

Abstract

Previous data have linked omega-3 fatty acids with risk of dementia. We aimed to assess the longitudinal relationships of omega-3 polyunsaturated fatty acid intake as well as blood biomarkers with risk of Alzheimer's disease (AD), dementia, or cognitive decline. Longitudinal data were derived from 1135 participants without dementia (mean age = 73 y) in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort to evaluate the associations of omega-3 fatty acid supplementation and blood biomarkers with incident AD during the 6-y follow-up. A meta-analysis of published cohort studies was further conducted to test the longitudinal relationships of dietary intake of omega-3 and its peripheral markers with all-cause dementia or cognitive decline. Causal dose-response analyses were conducted using the robust error meta-regression model. In the ADNI cohort, long-term users of omega-3 fatty acid supplements exhibited a 64% reduced risk of AD (hazard ratio: 0.36, 95% confidence interval: 0.18, 0.72; P = 0.004). After incorporating 48 longitudinal studies involving 103,651 participants, a moderate-to-high level of evidence suggested that dietary intake of omega-3 fatty acids could lower risk of all-cause dementia or cognitive decline by ∼20%, especially for docosahexaenoic acid (DHA) intake (relative risk [RR]: 0.82, I2 = 63.6%, P = 0.001) and for studies that were adjusted for apolipoprotein APOE ε4 status (RR: 0.83, I2 = 65%, P = 0.006). Each increment of 0.1 g/d of DHA or eicosapentaenoic acid (EPA) intake was associated with an 8% ∼ 9.9% (Plinear < 0.0005) lower risk of cognitive decline. Moderate-to-high levels of evidence indicated that elevated levels of plasma EPA (RR: 0.88, I2 = 38.1%) and erythrocyte membrane DHA (RR: 0.94, I2 = 0.4%) were associated with a lower risk of cognitive decline. Dietary intake or long-term supplementation of omega-3 fatty acids may help reduce risk of AD or cognitive decline.

Key Findings

Dietary intake or long-term supplementation of omega-3 fatty acids may help reduce risk of AD or cognitive decline.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 1135
Age Range See abstract
Condition cognitive

MeSH Terms

  • Humans
  • Aged
  • Alzheimer Disease
  • Prospective Studies
  • Docosahexaenoic Acids
  • Eicosapentaenoic Acid
  • Fatty Acids, Omega-3
  • Cognitive Dysfunction
  • Dietary Supplements
  • Cohort Studies
  • Eating

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Meta-Analysis, Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, Non-P.H.S.
  • Vertical: omega-3-cognition

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09