Nutritional/metabolic response in older cancer patients.

The combination of age-related muscle loss (sarcopenia) and the diagnosis of cancer (and the onset of cachexia) is likely a metabolic challenge that skeletal muscle of older cancer patients is not prepared to handle. Albeit to a smaller extent than healthy older controls, the skeletal muscle of older cancer patients is still acutely anabolic to the provision of amino acids. To provide an anabolic stimulus to skeletal muscle during a time when it is susceptible to an advanced rate of breakdown due to cancer- and tumor-related factors, enhanced intake of protein and amino acid sources might be necessary and should likely be higher than the current US recommended daily intake of 0.8 g protein/kg body weight/day. Future studies should investigate whether the acute effects of amino acids on muscle protein anabolism can be sustained over a longer period of time in the presence of cancer cachexia in older patients.