Pasture-Raised Red Meat Compared with Plant-Based Meat Alternatives Within Healthy Dietary Patterns: Effects on Polyunsaturated Fatty Acid Status and Cardiometabolic Health in a Randomized Dietary Intervention

Background The health effects of moderate consumption of pasture-raised red meat within healthy dietary patterns remain uncertain.Objective Determine whether inclusion of moderate amounts of pasture-raised red meat altered polyunsaturated fatty acid (PUFA) status compared with a vegetarian dietary pattern incorporating plant-based meat alternatives (PBMAs) and examine effects on cardiometabolic biomarkers and circulating lipidomic profiles METHODS: In a 10-week free-living randomized dietary intervention, healthy adults consumed either a flexitarian dietary pattern including moderate amounts of pasture-raised red meat (3.3 serves/week at week 10) or a vegetarian dietary pattern incorporating PBMAs. Plasma fatty acids, cardiometabolic biomarkers, and lipidomic profiles were assessed at baseline, 5 weeks, and 10 weeks. Longitudinal changes were analysed using linear mixed-effects models accounting for repeated measures and household clustering. Benjamini-Hochberg correction was applied to prespecified plasma fatty acid outcomes and lipidomic analyses RESULTS: Seventy-eight participants completed the intervention. Plasma omega-3 PUFA docosapentaenoic acid (DPA) exhibited a significant intervention × time interaction, reflecting a decline in the vegetarian group between baseline and week 5 compared with the flexitarian group (estimate = -6.47 μmol/L, 95% CI: -10.39 to -2.56 μmol/L; p = 0.001), followed by recovery between week 5 and week 10 (estimate = -4.15 μmol/L, 95% CI: -8.07 to -0.24 μmol/L; p = 0.038). Following Benjamini-Hochberg correction, DPA remained significant (FDR-adjusted p = 0.030). No intervention × time effects were observed for cardiometabolic biomarkers. Among 259 lipid species, PE-O 39:6 was the only species remaining significant after correction for multiple testing (interaction p = 7.9 × 10-5; FDR = 0.020), remaining stable in the flexitarian group but declining in the vegetarian group CONCLUSIONS: Inclusion of moderate amounts of pasture-raised red meat did not adversely affect cardiometabolic biomarkers and was associated with maintenance of plasma DPA concentrations compared to a vegetarian dietary pattern incorporating PBMAs.Clinical trial registry number NCT04869163 https://clinicaltrials.gov/study/NCT04869163.