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Marine-Based Omega-3 Fatty Acids and Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Basirat A, Merino-Torres JF

Nutrients, 2025

9 citations

Abstract

Background: Metabolic syndrome (MetS) is a set of cardiometabolic abnormalities, including central obesity, dyslipidemia, hypertension, and hyperglycemia, that substantially increases the risk of cardiovascular disease and type 2 diabetes. Marine-derived omega-3 polyunsaturated fatty acids (n-3 PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may improve MetS components through triglyceride-lowering, anti-inflammatory, and insulin-sensitizing effects; however, randomized controlled trial (RCT) results remain inconsistent, and the influence of dose and intervention duration is unclear. Methods: Following PRISMA guidelines, PubMed, Embase, Scopus, and Web of Science were searched to June 2024 for RCTs in adults with MetS or its components. Eligible trials assessed marine-derived omega-3 supplementation (EPA/DHA) versus placebo or control and reported at least one MetS diagnostic criterion (triglycerides, HDL cholesterol, fasting plasma glucose, blood pressure, or waist circumference) or related parameter (LDL cholesterol, HOMA-IR, or HbA1c). Data were extracted in duplicate and quality assessed using the Cochrane Risk-of-Bias Tool. Trials were categorized by dose—low (2000 mg/day)—and duration: short-term (ST; ≤8 weeks), medium-term (MT; >8–12 weeks), and long-term (LT; >12 weeks). Meta-regression using ordinary least squares estimated dose–duration effects. Publication bias was assessed with funnel plots and Egger’s test for outcomes with ≥3…

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