Protein-Energy Malnutrition as a Determinant for Immuno-Senescence

Abstract

Human aging is associated with a loss of function involving organs or systems leading to pathologies such as cognitive impairment, macular degeneration, sarcopenia, frailty, cancer and increased susceptibility to infections. The erosion of the immune system is one of the age-associated failures observed. The delayed time for recovery and the increased susceptibility to infections with aging are directly associated with immune dysfunctions. Moreover, interventions aiming to protect the aged population such as vaccination have a limited efficiency. The eroded innate and adaptive immunity are responsible for this phenomenon. Several prophylactic and therapeutic approaches could restore immune function of immuno-depressed individuals. The nutritional approach is suitable for the aged-population since it requires less care than any medical approach and its cost is much lower which is an important factor when considering the health burden costs. Nevertheless, it is necessary to carefully and critically analyze the recent development in this field. In this review, we will first discuss the age-associated changes in immune functions, collectively named immune-senescence then discuss the age-associated changes in nutritional intake and metabolism with a particular interest in protein-energy malnutrition (PEM) to finally outline some of the candidate interventions to protect against PEM and immuno-senescence.