The role of nutrition in inflammaging

Old age is characterized by a peculiar low-grade, chronic, and "sterile" inflammatory state, which has been termed "inflammaging." This is believed to substantially contribute to the pathogenesis of many age-related diseases and to the progression of the ageing process. An adequate nutritional status is of great importance for maintaining proper immune system functionality and preventing frailty in the elderly. The purpose of this narrative review is to synthesize what is known about the interaction between inflammaging and nutrition, focusing on the role of the Mediterranean diet, gut microbiota and calorie restriction (CR) in reducing systemic inflammation and improving clinical outcomes. Dietary components may affect inflammation directly, counteracting the low grade age-related inflammation. In this regard, healthy diets, including the Mediterranean diet, are associated with lower concentrations of inflammatory mediators, like C-reactive protein (CRP) and Tumor Necrosis Factor-α (TNF-α), that are hallmarks of inflammaging. Among the components of a healthy diet, a higher intake of whole grains, vegetables and fruits, nuts and fish are all associated with lower inflammation. One area of promising research is the microbiome-ageing interaction. Indeed, dysbiosis plays a role in sub-optimal metabolism, immune function and brain function and contributes to the poor health and impaired well-being associated with ageing. Modulation of the gut microbiota has shown promising results in some disorders. Additionally, the discovery of several molecular pathways associated with ageing, and the characterization of the beneficial effects of calorie restriction (CR) in modulating metabolic pathways and preventing inflammation, should encourage research on CR mimetics, drugs able to promote lifespan and extend healthspan.