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

Area of Science:

• Cardiovascular Health
• Nutritional Science
• Metabolic Disorders

Background:

• Metabolic syndrome (MetS) is a cluster of conditions increasing cardiovascular disease and type 2 diabetes risk.
• Marine omega-3s (EPA/DHA) may improve MetS but trial results are inconsistent regarding dose and duration.
• Understanding optimal omega-3 supplementation for MetS requires further investigation.

Purpose of the Study:

• To systematically review randomized controlled trials (RCTs) on marine omega-3 supplementation for metabolic syndrome (MetS).
• To evaluate the influence of different doses and intervention durations on MetS components.
• To provide evidence-based recommendations for omega-3 use in MetS management.

Main Methods:

• A systematic literature search of PRISMA-guided RCTs was conducted across major databases.
• Data on MetS criteria and related parameters were extracted from 21 RCTs (n ≈ 1950).
• Meta-regression analyzed dose-duration effects, with trials categorized by dose (<1000, 1000-2000, >2000 mg/day) and duration (≤8, >8-12, >12 weeks).

Main Results:

• High-dose omega-3 supplementation (>2000 mg/day) significantly reduced triglycerides, particularly in long-term and short-term interventions.
• Medium-dose supplementation also showed triglyceride reduction, though less pronounced than high-dose.
• Low-dose supplementation was associated with increased LDL cholesterol; effects on HDL cholesterol, blood pressure, and glucose were inconsistent or insufficient for meta-analysis.

Conclusions:

• Marine-derived omega-3s, especially high doses (>2000 mg/day) for ≥8 weeks, effectively reduce triglycerides in MetS.
• Benefits for HDL cholesterol and blood pressure are inconsistent, and fasting glucose is largely unaffected.
• High-dose omega-3s can be considered for MetS management, but LDL cholesterol increases require monitoring; further long-term RCTs are needed.