Omega-3, omega-6, and total dietary polyunsaturated fat for prevention and treatment of type 2 diabetes mellitus: systematic review and meta-analysis of randomised controlled trials

Study answer

What this study found

Increasing long-chain omega-3, alpha-linolenic acid, omega-6, or total PUFA had little or no effect on prevention or treatment of type 2 diabetes or on glucose metabolism. Long-chain omega-3 did not reduce diabetes diagnosis, with RR 1.00 (0.85 to 1.17) in 58,643 participants across 17 trials. Effects on HbA1c, fasting glucose, fasting insulin, and HOMA-IR were generally near zero for long-chain omega-3 and alpha-linolenic acid, and omega-6 or total PUFA also showed no clinically important benefit. The authors concluded that supplemental long-chain omega-3 should not be encouraged for…

Study & population

Systematic review and meta-analysis of randomized controlled trials in adults aged 18 years and older at risk of diabetes, including healthy participants and people with diagnosed diabetes or impaired glucose metabolism.

Intervention

Randomized trials evaluated increased intake or supplementation with long-chain omega-3 fatty acids, alpha-linolenic acid, omega-6 fatty acids, or total polyunsaturated fatty acids (PUFA).

Key limitation

Evidence was uneven across interventions, with far fewer trials and participants for alpha-linolenic acid, omega-6, and total PUFA than for long-chain omega-3.

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Original abstract