title: Clinical effectiveness of protein and amino acid supplementation on building muscle mass in elderly people: a meta-analysis.
abstract: OBJECTIVE
  A major reason for the loss of mobility in elderly people is the gradual loss of lean body mass known as sarcopenia. Sarcopenia is associated with a lower quality of life and higher healthcare costs. The benefit of strategies that include nutritional intervention, timing of intervention, and physical exercise to improve muscle loss unclear as finding from studies investigating this issue have been inconsistent. We have performed a systematic review and meta-analysis to assess the ability of protein or amino acid supplementation to augment lean body mass or strength of leg muscles in elderly patients.
  
  
  METHODS
  Nine studies met the inclusion criteria of being a prospective comparative study or randomized controlled trial (RCT) that compared the efficacy of an amino acid or protein supplement intervention with that of a placebo in elderly people (≥ 65 years) for the improvement of lean body mass (LBM), leg muscle strength or reduction associated with sarcopenia.
  
  
  RESULTS
  The overall difference in mean change from baseline to the end of study in LBM between the treatment and placebo groups was 0.34 kg which was not significant (P = 0.386). The overall differences in mean change from baseline in double leg press and leg extension were 2.14 kg (P = 0.748) and 2.28 kg (P = 0.265), respectively, between the treatment group and the placebo group.
  
  
  CONCLUSIONS
  These results indicate that amino acid/protein supplements did not increase lean body mass gain and muscle strength significantly more than placebo in a diverse elderly population.
authors.affiliation: Department of Geriatrics, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Zhe-rong
authors.initials: ZR
authors.lastname: Xu
authors.affiliation: Department of Geriatrics, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Zhong-ju
authors.initials: ZJ
authors.lastname: Tan
authors.affiliation: Department of Geriatrics, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Geriatrics, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Qi-feng
authors.initials: QF
authors.lastname: Gui
authors.affiliation: State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Department of Geriatrics, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Yun-mei
authors.initials: YM
authors.lastname: Yang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000596:Amino Acids / Q000008:administration & dosage*; D001823:Body Composition / Q000187:drug effects; D004044:Dietary Proteins / Q000008:administration & dosage*; D019587:Dietary Supplements; D015444:Exercise; D005260:Female; D016330:Frail Elderly; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000503:physiopathology; D055948:Sarcopenia / Q000178:diet therapy* / Q000503:physiopathology / Q000517:prevention & control; D016896:Treatment Outcome
chemical_list: D000596:Amino Acids; D004044:Dietary Proteins