Omega-3 fatty acids in vegetarian and vegan diets: Translating evidence into practice

Vegetarian and vegan diets are consistently associated with reduced cardiometabolic risk, despite providing minimal amounts of long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs), key precursors of bioactive lipid mediators, raising questions about n-3 PUFA metabolism and requirements in plant-based populations. This review examines current evidence on the metabolic fate of alpha-linolenic acid (ALA), its conversion to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and the implications for n-3 PUFA-derived signaling pathways. Although conversion efficiency is limited, it is influenced by dietary and non-dietary factors and may be supported by adaptive mechanisms that preserve tissue DHA. Individuals following plant-based diets exhibit lower EPA and DHA status, yet maintain favorable health profiles, suggesting that overall dietary context and endogenous regulation may mitigate reduced intake of preformed n-3 PUFAs. Targeted strategies, including optimizing ALA intake and using algae-derived EPA/DHA, effectively improve biomarker status. Understanding these mechanisms may help redefine n-3 PUFA requirements in plant-based populations.