Omega-3-Fortified Foods as Designed Delivery Systems: Source Quality, Matrix Performance, Retained Dose, and Evidence-Based Claims

Omega-3-fortified foods sit at the interface of lipid science, food technology, and prevention-oriented nutrition. The aim of this narrative review is to define practical criteria for evaluating whether fortified foods can deliver physiologically relevant eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) rather than merely declare omega-3 addition. This review focuses on fish oils, fish-processing by-product oils, single-cell oils, and encapsulated or emulsified delivery systems used in dairy products, bakery products, beverages, spreads, eggs, infant and maternal foods, nutrition bars, and related functional foods. It integrates evidence on raw material composition, refining, oxidative stability, food-matrix compatibility, retained dose during shelf life, bioavailability, biomarker response, health benefits, safety concerns, and regulatory communication. The proposed source-to-status quality-by-design framework emphasizes that applied value depends on traceable source selection, analytical quality control, matrix-specific protection, end-of-shelf-life verification, transparent dose labeling, and claims that remain proportional to evidence. Ordinary low-dose fortified foods should not be presented as equivalents of prescription omega-3 products or as general disease-prevention tools. Their defensible role is status-oriented dietary optimization in populations with low EPA/DHA intake.