Clinical effectiveness of fish oil on arterial stiffness: A systematic review and meta-analysis of randomized controlled trials

Aims The increase of arterial stiffness is an independent risk factor for cardiovascular diseases (CVD). Fish oil supplementation was shown to reduce the risk of CVD outcomes. However, the effects of fish oil on arterial stiffness remains controversial. This meta-analysis summarized existing randomized clinical trials (RCTs) to determine whether fish oil can affect arterial stiffness in adults. Data synthesis Systematic searches were performed using the PubMed/Medline, EMbase, Cochrane database, Clinical trials, and Web of Science. All RCTs assessed the effect of fish oil intervention on carotid to femoral-Pulse Wave Velocity (cf-PWV), brachial to ankle-PWV (ba-PWV), augmentation index (AIx) and AIx75 were considered. A fixed-effect model was used to calculate the pooled effect.A total of 14 RCTs were included. The pooled data analysis showed that fish oil significantly reduced PWV levels (SMD: −0.145, 95%CI: −0.265 to −0.033, P = 0.012) compared to the control group. In subgroup analyses, a significant decrease in PWV was found in trials that fish oil with low dosages (≤1.8 g/d), short time (<24 weeks), low DHA to EPA ratio (DHA/EPA<1) and among young participant (<50 years old). Besides, the effect of fish oil was more obvious in ba-PWV compared to cf-PWV. In contrast, the effect of fish oil supplementation on AIx (WMD: −0.588%, 95% CI: −2.745 to 1.568, P = 0.593) and AIx75 (WMD: 0.542%, 95% CI: −1.490 to 2.574, P = 0.601) was nonsignificant. Conclusions The current study showed that fish oil supplementation had a beneficial effect on pulse wave velocity.