Laboratorio de Investigacao em Nutricao Clinica e Esportiva (Labince), Faculdade de Nutricao, Universidade Federal de Goias, Goiania, Brazil.
School of Health Sciences, Faculty Health Science, Trident University International, Cypress, CA 90630, United States.
Curr Pharm Des. 2020;26(9):970-978. doi: 10.2174/1381612826666200218100420.
Cancer patients display systemic inflammation, which leads to an increase in protein catabolism, thus promoting the release of free amino acids to further support metabolism and remodelling of muscle proteins. Inflammation associated with tumor growth leads to malnutrition, a factor that increases the risk of developing cachexia. With cancer-induced cachexia, nutritional interventions have gained traction as a preventative method to manage this condition. Currently, cancer consensus recommendations suggest a protein intake above 1.0 g/kg.day-1 up to 2.0 g/k.day-1 for cancer patients, although an ideal amount for some amino acids in isolation has yet to be determined. Due to controversy in the literature regarding the benefits of the biochemical mechanisms of various muscle mass supplements, such as L-leucine (including whey protein and BCAA), β-hydroxy-beta-methyl butyrate (HMβ), arginine, glutamine and creatine, several studies have carefully examined their effects. L-leucine and its derivatives appear to regulate protein synthesis by direct or indirect activation of the mTORC1 pool of kinases, further promoting muscle protein balance. Arginine and glutamine may act by reducing inflammation and infection progression, thus promoting improvements in food intake. Creatine exerts anabolic activity, acting as an immediate energy substrate to support muscle contraction further increasing lean mass, mainly due to greater water uptake by the muscle. In this narrative review, we highlighted the main findings regarding protein consumption and amino acids to mitigate cancer-induced skeletal muscle depletion.
癌症患者表现出全身性炎症，这导致蛋白质分解代谢增加，从而促进游离氨基酸的释放，以进一步支持代谢和肌肉蛋白的重塑。与肿瘤生长相关的炎症导致营养不良，这是增加恶病质风险的一个因素。随着癌症引起的恶病质，营养干预作为一种预防方法得到了重视，以管理这种情况。目前，癌症共识建议癌症患者的蛋白质摄入量超过 1.0 g/kg.day-1，最高可达 2.0 g/kg.day-1，尽管某些氨基酸的理想摄入量尚未确定。由于文献中存在关于各种肌肉质量补充剂的生化机制的益处的争议，例如 L-亮氨酸（包括乳清蛋白和支链氨基酸）、β-羟基-β-甲基丁酸（HMβ）、精氨酸、谷氨酰胺和肌酸，因此一些研究仔细检查了它们的作用。L-亮氨酸及其衍生物似乎通过直接或间接激活 mTORC1 激酶池来调节蛋白质合成，进一步促进肌肉蛋白平衡。精氨酸和谷氨酰胺可能通过减少炎症和感染的进展来发挥作用，从而促进食物摄入的改善。肌酸发挥合成代谢作用，作为支持肌肉收缩的即时能量底物，进一步增加瘦体重，主要是由于肌肉吸收更多的水分。在这篇叙述性综述中，我们强调了关于蛋白质消耗和氨基酸的主要发现，以减轻癌症引起的骨骼肌耗竭。
