Nutrients 2022 Apr 12;14(8):1608 Do B Vitamins Enhance the Effect of Omega-3 Polyunsaturated Fatty Acids on Cardiovascular Diseases? A Systematic Review of Clinical Trials Jie Zhu 1, Peng-Cheng Xun 2, Marissa Kolencik 1, Ke-Feng Yang 3, Alyce D Fly 4, Ka Kahe 5 6
PMID: 35458173 PMCID: PMC9032763 DOI: 10.3390/nu14081608 Free PMC article Abstract Studies have suggested that B vitamins or omega-3 polyunsaturated fatty acids (PUFAs) may deter the development of cardiovascular disease (CVD). This systematic review aims to examine whether the combined supplementation of both B vitamins and omega-3 PUFAs could provide additional beneficial effects to prevent CVD beyond the effect of each supplement based on clinical trials published up to December 2021. The overall findings are inconsistent and inconclusive, yet the combined supplementation of these two nutrients may be more effective at reducing plasma homocysteine, triglyceride, and low-density lipoprotein-cholesterol than the individual components. The underlying mechanisms mainly include alleviating endothelial dysfunction, inhibiting atherosclerosis and lesion initiation, reducing oxidative stress, suppressing activation of pro-inflammatory cytokines, regulating endothelial nitric oxide synthase, and interfering with methylation of genes that promote atherogenesis. Although biologically plausible, the existing literature is insufficient to draw any firm conclusion regarding whether B vitamins can further enhance the potential beneficial effects of omega-3 PUFA intake on either primary or secondary prevention of CVD. The inconsistent findings may be largely explained by the methodological challenges. Therefore, well-designed high-quality trials that will use the combined supplementation of B vitamins and omega-3 PUFAs or dietary patterns rich in these two types of nutrients are warranted. Keywords: B vitamins; cardiovascular disease; omega-3 PUFAs; supplementation. Conflict of interest statement The authors declare no conflict of interest.
What is already known on this topic Observational studies have reported inverse associations of cardiovascular disease with intake or plasma concentrations of B vitamins (folate and vitamin B-6) and with omega 3 fatty acids Randomised trials of B vitamins have failed to find any significant effects on vascular disease. Trials of omega 3 fatty acids have produced conflicting results What this study adds This randomised placebo controlled trial found no significant effects of daily dietary supplementation with B vitamins or with omega 3 fatty acids on risk of major cardiovascular events in patients with established coronary or cerebrovascular disease The results do not support the routine use of such dietary supplements for prevention of cardiovascular disease in people with a history of ischaemic heart disease or ischaemic stroke, especially when supplementation is introduced after the acute phase of the initial event