Bioequivalence of long-chain omega-3 polyunsaturated fatty acids from foods enriched with a novel vegetable-based omega-3 delivery system compared to gel capsules: a randomized controlled cross-over acute trial

PURPOSE: To evaluate bioavailability of omega-3 long-chain polyunsaturated fatty acids (LCPUFA) from foods enriched with novel vegetable-based encapsulated algal oil across Australian and Singaporean populations. METHODS: 27 men (n = 12 Australian European; n = 15 Singaporean Chinese), 21–50 yr; 18–27.5 kg/m(2), with low habitual intake of omega-3 LCPUFA completed a multicentre randomised controlled acute 3-way cross-over single-blind trial. They consumed, in random order 1-week apart after an overnight fast, standard breakfast meals including 400 mg docosahexanoic acid (DHA) from either extruded rice snacks or soup both containing cauliflower-encapsulated HiDHA(®) algal oil or gel capsules containing HiDHA(®) algal oil. Blood samples for analysis of plasma DHA and eicosapentaenoic acid (EPA) were taken pre-meal and after 2, 4, 6, 8 and 24 h. Primary analyses comparing 24-h incremental area under the plasma DHA, EPA and DHA + EPA concentration (µg/ml) curves (iAUC(0-24 h)) between test foods were performed using linear mixed models by including ethnicity as an interaction term. RESULTS: Plasma iAUC(0-24 h) did not differ significantly between test foods (adjusted mean [95% CI] plasma DHA + EPA: extruded rice snack, 8391 [5550, 11233] µg/mL*hour; soup, 8862 [6021, 11704] µg/mL*hour; capsules, 11,068 [8226, 13910] µg/mL*hour, P = 0.31) and did not differ significantly between Australian European and Singaporean Chinese (treatment*ethnicity interaction, P = 0.43). CONCLUSION: The vegetable-based omega-3 LCPUFA delivery system did not affect bioavailability of omega-3 LCPUFA in healthy young Australian and Singaporean men as assessed after a single meal over 24 h, nor was bioavailability affected by ethnicity. This novel delivery system may be an effective way to fortify foods/beverages with omega-3 LCPUFA. TRIAL REGISTRATION: The trial was registered with clinicaltrials.gov (NCT04610983), date of registration, 22 November 2020. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00394-021-02795-7.