Background/Aims: Vegetarians and vegans have a lowered intake of preformed Docosahexaenoic acid (DHA) compared to omnivorous populations due to the limited intake of fish and animal products. As such, their omega-3 index has been reported as being 50-60% less than those who consume marine products which are notoriously high in DHA and (Eicosapentaenoic acid) EPA. This research aims to examine the evidence for the relationship between supplementing with algal forms of DHA and increasing phospholipid DHA concentrations in vegetarians and vegans.
Methods: A systematic literature review was performed using the SCOPUS and Web of Science databases. Included studies assessed the effect of non-animal sources of DHA supplementation on vegetarian and/or vegan populations reporting on plasma and/or serum DHA or omega-3 indices. A search for unpublished literature was not performed, although reference lists of the included publications were examined for additional relevant studies. No date exclusions were set. NHMRC levels of evidence were applied to the included studies.
Results: Three randomised controlled trials and two prospective cohort studies met the inclusion criteria. All five studies were unified reporting supplementing with non-animal forms of DHA significantly increases DHA status in vegetarians and vegans.
Conclusion: DHA status is significantly increased when algal DHA supplementation is used in vegan and vegetarian populations. Research is warranted to determine if increasing the omega-3 status in vegetarians and vegans will further decrease their already lowered risk of death from ischemic heart disease compared to omnivorous populations.
Funding Source: N/A