Multidimensional evidence assessment and mechanistic integration of the health effects of red and white meat.

The health effects of red and white meat have been debated for decades, and the conventional species-based binary classification fails to capture their nutritional heterogeneity and differential disease risks. This review reconstructs the meat-health evaluation paradigm by integrating multidisciplinary evidence from epidemiology, molecular biology, and food science. Current findings demonstrate that traditional definitions overlook intra-species variation and inter-species paradoxes, underscoring the need to classify meat more precisely by anatomical cut and processing method. Processed meat, recognized as a Group 1 carcinogen, presents fundamentally distinct hazards from unprocessed red meat; moderate consumption of the latter may allow a reasonable balance between essential nutrients such as heme iron and vitamin B12 and associated pathophysiological risks. Mechanistically, the adverse effects of red meat are driven by a convergent network involving heme iron, N-glycolylneuraminic acid (Neu5Gc), trimethylamine-N-oxide (TMAO), and processing-derived toxicants including N-nitroso compounds (NOCs), heterocyclic amines (HCAs), and polycyclic aromatic hydrocarbons (PAHs). In contrast, white meat generally lacks these key toxic components and is enriched in omega-3 polyunsaturated fatty acids (PUFAs) such as EPA and DHA, which provide cardioprotective and neuroprotective benefits, although excessive high-temperature cooking may diminish these advantages. Correspondingly, international dietary guidelines are converging toward the principle of "strictly restrict processed meat, limit unprocessed red meat, and prioritize white meat". Emerging precision strategies include genetic risk stratification, probiotic and dietary fiber interventions targeting the gut microbiota-TMAO axis, and low-temperature/clean-label processing technologies. Future directions should leverage single-cell and spatial multi-omics to elucidate organ-specific toxicity, build tripartite gene-microbiota-nutrient interaction models to enable individualized risk prediction, and apply CRISPR-based breeding to improve the nutritional-toxicological profile of red meat, while integrating AI-driven personalized dietary guidance. Collectively, these advancements will drive meat consumption toward a more nutritionally optimized, health-protective, and environmentally sustainable paradigm.