Plain language summary
This systematic review and meta-analysis reports that high dose omega 3 at a dose of 3g/day with 90% purity significantly slowed the progression of atherosclerosis and is a promising mechanism for reducing cardiovascular (CVD) incidents. The study reviewed 6 articles from 2016-2017 with a total of 693 participants, which met the criteria of omega 3 and a primary outcome on atherosclerosis. Only one trial was placebo controlled with the remaining five open-label trials with no placebo. Four of the trials were conducted in Japan using a highly purified EPA whilst the remaining trials used an EPA / DHA combination. The effect of high dose omega 3 was significant even after removing the two most influential studies. Preclinical studies in animal models show that Omega 3 slows atherosclerosis progression through various molecular mechanisms. In humans there is less conclusive evidence and observational studies report that dietary intake of Omega 3 has no significant correlation with coronary artery calcification, the measure used to assess atherosclerosis. The limitation of this study is that different technologies were used to assess atherosclerosis across the selected trials. However, the authors conclude that the anti-atherosclerotic properties of high-dose OM3 are one potential mechanism in reducing CVD risk.
Abstract
A recent randomized controlled trial (RCT), the Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT), reported that high-dose marine omega-3 fatty acids (OM3) significantly reduce cardiovascular disease (CVD) outcomes, yet the mechanisms responsible for this benefit remain unknown. To test the hypothesis that high-dose OM3 is anti-atherosclerotic, we performed a systematic review and meta-analysis of RCT of high-dose OM3 on atherosclerosis. The protocol of this systematic review was registered with PROSPERO (CRD42019125566). PubMed, Embase, Cochran Central Register for Controlled Trials, and Clinicaltrials.gov databases were searched using the following criteria: adult participants, high-dose OM3 (defined as ≥3.0 g/day, or in Japan 1.8 g/day and purity ≥90%) as the intervention, changes in atherosclerosis as the outcome, and RCTs with an intervention duration of ≥6 months. A random-effects meta-analysis was used to pool estimates across studies. Among the 598 articles retrieved, six articles met our criteria. Four RCTs evaluated atherosclerosis in the coronary and two in the carotid arteries. High-dose OM3 significantly slowed the progression of atherosclerosis (standardized mean difference -1.97, 95% confidence interval -3.01, -0.94, p < 0.001). The results indicate that anti-atherosclerotic effect of high-dose OM3 is one potential mechanism in reducing CVD outcomes demonstrated in the REDUCE-IT trial.
Methodological quality
Jadad score
:
3
Allocation concealment
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No
