a Faculty of Health Sciences and Medicine , Bond University , Gold Coast , Australia.
b Nutrition and Dietetics , Mater Group , Brisbane , Australia.
Int J Radiat Biol. 2019 Apr;95(4):480-492. doi: 10.1080/09553002.2018.1466209. Epub 2018 May 3.
Amino acids are involved in many physiological processes in the body and serve as building blocks of proteins which are the main component of muscle mass. Often patients with cancer experience muscle wasting, which is associated with poor outcomes. The purpose of this paper is to discuss amino acid kinetics in cancer, review the evidence on the response to nutrition in patients with cancer, and to give recommendations on the appropriate level of amino acid or protein intake in cancer. Current evidence shows that amino acid kinetics in patients with cancer are disturbed, as reflected by increased and decreased levels of plasma amino acids, an increased whole body turnover of protein and muscle protein breakdown. A few studies show beneficial effects of acute and short-term supplementation of high protein meals or essential amino acid mixtures on muscle protein synthesis.
Cancer is associated with disturbances in amino acid kinetics. A high protein intake or supplementation of amino acids may improve muscle protein synthesis. Future research needs to identify the optimal level and amino acid mixtures for patients with cancer, in particular for those who are malnourished.
氨基酸在体内参与许多生理过程，并作为蛋白质的构建块，而蛋白质是肌肉质量的主要组成部分。癌症患者常经历肌肉消耗，这与不良结局有关。本文旨在讨论癌症中的氨基酸动力学，回顾癌症患者营养反应的证据，并就癌症患者适当的氨基酸或蛋白质摄入量提出建议。目前的证据表明，癌症患者的氨基酸动力学受到干扰，表现为血浆氨基酸水平升高和降低、全身蛋白质周转率增加和肌肉蛋白分解增加。一些研究表明，急性和短期补充高蛋白膳食或必需氨基酸混合物对肌肉蛋白质合成有有益的影响。
癌症与氨基酸动力学紊乱有关。高蛋白摄入或氨基酸补充可能会改善肌肉蛋白质合成。未来的研究需要确定癌症患者（特别是营养不良患者）的最佳水平和氨基酸混合物。
