Effects of whey protein supplement in the elderly submitted to resistance training: systematic review and meta-analysis

Abstract

Abstract:We performed a systematic review to map the evidence and analyze the effect of whey protein supplementation in the elderly submitted to resistance training. Methods: A comprehensive search on Medline, LILACS, EMBASE and the Cochrane Library for relevant publications was conducted until August 2015. The terms used in the search were: "Resistance Training"; "Whey protein"; "elderly". Two authors independently assessed abstracts, texts in full and made critical appraisal. Results: A total of 632 studies were screened. Five studies were included composing a sample of 391 patients. The supplement whey protein was associated with higher total protein ingestion 9.40 (95% CI 4.03 to 14.78), and with an average change in plasma leucine concentration ranging from 406µmol/L to 490µmol/L compared with the control group. The supplementation was also associated with increased mixed muscle protein synthesis 1.26 (95% CI 0.46 to 2.07) compared to control group. Just one trial compared lean body mass in the group receiving whey protein supplementation and the control group (n=80) 0.07 (95% CI -0.37 to 0.51). Conclusion: We observed an increase in total protein intake, resulting in increased concentration of leucine and mixed muscle protein synthesis rate. No significant increase related to muscle mass or strength were observed.

Effects of Whey Protein Supplementation Pre- or Post-Resistance Training on Muscle Mass, Muscular Strength, and Functional Capacity in Pre-Conditioned Older Women: A Randomized Clinical Trial

“…If adequate protein and energy intake occurs in untrained individuals starting a RT program, the stimulation provided by RT overcomes the stimulus coming from diet [ 15 ]. Therefore, the lack of favorable results for WP supplementation associated with RT [ 10 ] may be due to the competition of anabolic stimuli (feeding and training together).…”

“…It can be assumed that a greater amount of leucine could result in a higher rate of protein synthesis when associated with a training stimulus, which may attenuate the losses related to aging. Information regarding protein supplementation in older adults is still controversial, mainly on the effectiveness of protein supplementation on muscle mass and strength when associated with training [ 6 , 10 , 11 , 12 ]. Possible explanations for these conflicting results are the anabolic stimulus from the food and training together, the amount of baseline protein consumption, the level of training, and the timing of nutrient intake [ 12 , 13 , 14 , 15 , 16 ].…”

Efeito da suplementação de leucina em idosos praticantes de treinamento resistido: uma revisão sistemática

“…Assim, um aumento significativo no anabolismo (MPS) e/ou uma redução no catabolismo (MPB), de modo que o saldo proteico permaneça positivo e possa resultar na acumulação de proteínas do músculo. O equilíbrio da proteína líquida é mantido pela ingestão de refeições e/ou suplementos proteicos que resultam em hiperaminoacidemia sistêmica que é estimuladora para a síntese de novas proteínas 11,12,42 .…”

“…São relatadas reduções nas taxas de síntese proteica muscular em repouso em idosos na ordem de 20-30%, em comparação com os jovens 11,12,42 . Porém, parece que o equilíbrio do saldo proteico basal no músculo esquelético não está comprometido com o envelhecimento, mas existem outras exigências e demandas na via 45 .…”

“…Porém, em idosos após o exercício, o processo de síntese proteica responsável pelo aumento de massa magra, não é eficiente quanto comparado de um jovem, e assim, necessita de maiores dosagens de proteína para ativação e proliferação desta via 11 . O aumento do aporte e ingestão proteica diária e/ou após exercício é uma estratégia recentemente investigada e encorajada em idosos praticantes de treinamento resistido (TR) 11,12 .…”