Pathophysiology of anorexia of aging

A relative reduction in food intake in older versus younger individuals is commonly present in the general population and is often referred to as anorexia of aging. In most cases, anorexia of aging represents a normal physiological phenomenon, but sometimes it may underlie vulnerability for the frailty syndrome and increased mortality. However, the mechanisms responsible for anorexia of aging are not completely understood. In this review, we focused on the biological mechanisms which may trigger development in older subjects and experimental animals a resistance to anabolic and orexigenic peptide messengers including neuropeptide Y, ghrelin and growth hormone. The putative role of the aging gut, microbial intestinal contamination and the immune system are also discussed. (c) 2009 Elsevier Masson SAS. All rights reserved.