PROTEIN, AMINO ACID METABOLISM AND THERAPY: Edited by Sidney M. Morris Jr. and Alessandro LavianoThe conserved role of protein restriction in aging and diseaseMirzaei, Hameda; Raynes, Rachela; Longo, Valter D.a,bAuthor Information aLongevity Institute and Davis School of Gerontology, University of Southern California, Los Angeles, California, USA bIFOM, FIRC Institute of Molecular Oncology, Milano, Italy Correspondence to Valter D. Longo, PhD, Longevity Institute and Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA. Tel: +1 213 740 6212; e-mail: firstname.lastname@example.org Current Opinion in Clinical Nutrition and Metabolic Care: January 2016 - Volume 19 - Issue 1 - p 74-79 doi: 10.1097/MCO.0000000000000239 Buy Metrics Abstract Purpose of review Dietary interventions are effective strategies for preventing disease and promoting health span. Many of the effects of dietary restriction are linked to amino acid and protein levels and their regulation of nutrient-signaling pathways. Thus, protein restriction is a promising therapeutic strategy for preventing aging-related diseases and extending life span. Recent findings Studies in yeast and flies have shown that amino acid restriction promotes longevity and protection. In rodents, protein restriction extends life span and alleviates detrimental aging phenotypes. Finally, clinical trials in middle-aged adults have demonstrated the role of a protein-restricted diet in promoting health span. Interestingly, the population over the age of 65 may not benefit from severe protein restriction potentially because of the increased physiological decline that leads to decreased amino acid absorption and altered protein synthesis. Summary Protein restriction can have profound effects on health and longevity, but excessive restriction is detrimental, particularly in the very old. The investigation of the mechanisms that modulate nutrient-sensing pathways is important to understand how regulation of protein intake can optimize health span and longevity. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.