Phytonutrients as Potential Dietary Supplements to Ameliorate Sarcopenia via the Involvement of Autophagic Pathway

Although sarcopenia has been a serious public health concern worldwide in recent years, its effective prevention and intervention measures are still lacking. The latest research has found that autophagy dysfunction is an essential mechanism in the pathogenesis of sarcopenia. And meanwhile, increasing studies have shown that phytonutrients consumption is positively correlated with the maintenance of skeletal muscle mass and strength, which involves the regulation of the autophagy pathway. However, due to the opposite environmental-dependent effect of autophagy in sarcopenia, targeting autophagy by phytonutrients as the treatment of sarcopenia is sometimes considered controversial. Thus, in this review, based on the illustration of the relationship between autophagy and skeletal muscle and the complex changes of autophagy in sarcopenia, the phytonutrients ameliorating sarcopenia by regulating autophagy are reviewed with emphasis, and the possible underlying mechanisms are systematically summarized. Despite some controversies, most current studies support the idea that maintaining basal and functional autophagy contributes to the treatment of sarcopenia. Several phytonutrients exhibit substantial beneficial effects on sarcopenia by targeting autophagy, with polyphenols (especially catechins and urolithin A) considered to be of potentially effective clinical relevance. Hence, the development of phytonutrients is a promising approach to the treatment of sarcopenia and its complications.