HealthDay News — Polyunsaturated fatty acids (PUFA) have little to no effect on the prevention or treatment of type 2 diabetes mellitus, according to a review published online Aug. 21 in The BMJ.
Tracey J. Brown, from Norwich Medical School at the University of East Anglia in the United Kingdom, and colleagues conducted a systematic review and meta-analysis of 83 randomized controlled trials with a duration of ≥24 weeks to examine the effects of increasing α-linolenic acid, long-chain omega-3, omega-6, or total PUFA on diabetes diagnosis and glucose metabolism.
Most of the trials assessed the effects of supplementary long-chain omega-3; 10 were at low summary risk of bias. The researchers found that long-chain omega-3 had little or no impact on the likelihood of diagnosis of diabetes (relative risk, 1.00; 95 percent confidence interval, 0.85 to 1.17) or measures of glucose metabolism. When the supplemental long-chain omega-3 dose was >4.4 g/day, there was a suggestion of negative outcomes. The effects of α-linolenic acid, omega-6, and total PUFA on diabetes diagnosis were unclear, and they had little to no effect on glucose metabolism, except for a possible increase in fasting insulin with increasing α-linolenic acid. No evidence was found indicating that the omega-3/omega-6 ratio is important for diabetes or glucose metabolism.
“No convincing evidence suggests that altering intakes of long-chain omega-3, α-linolenic acid, omega-6, or total PUFA alters glucose metabolism or risk of diabetes,” the authors write. “Supplemental long chain omega-3 should not be encouraged for prevention or treatment of diabetes.”