Early Nutritional Interventions for Metabolic Inflammation in Older Adults and Development of Functional Ingredients for Age-Friendly Foods

Metabolic inflammation in older adults is a chronic low-grade inflammatory state resulting from the combined effects of nutritional imbalance, metabolic abnormalities, immune remodeling, and alterations in the gut microbiota during aging, and constitutes an important pathological basis for age-related diseases such as atherosclerosis, type 2 diabetes mellitus, metabolic dysfunction-associated steatotic liver disease, and cognitive impairment. Shifting the intervention window to the pre-disease stage or the early stage of metabolic abnormalities is an important strategy for promoting healthy aging and reducing the burden of chronic diseases. With a focus on the characteristics of metabolic inflammation in older adults, multidimensional evaluation approaches were systematically summarized, including conventional inflammatory markers, novel biomarkers, omics technologies, dietary inflammatory indices, and imaging techniques. Particular emphasis was placed on the mechanisms by which early nutritional interventions regulate inflammatory and metabolic homeostasis through modulation of digestion and absorption, food-gut microbiota interactions, cellular biochemical reactions, inflammatory signaling pathways, and cellular and tissue constituents. The regulatory effects and human evidence of typical dietary components, including dietary carbohydrates, dietary proteins and amino acids, dietary lipids, and dietary phytochemicals, were also summarized. On this basis, the translational pathways of functional ingredients for age-friendly foods were analyzed from the perspectives of functional ingredient screening, stabilization and delivery, age-adapted application, and evaluation. Future directions involving multidimensional digital-intelligent screening and evaluation, green processing and digital manufacturing, and coordinated optimization of nutritional function and sensory properties were further discussed, providing a theoretical basis and research reference for early nutritional interventions targeting metabolic inflammation in older adults and for the development and application of functional ingredients in age-friendly foods.