The protein intake of older people has gained increasing scientific interest as a potential factor to delay the age-associated decline in muscle mass and consequently to counteract the development of sarcopenia. The skeletal muscle of older people seems less responsive to the anabolic stimulus of protein intake. Therefore, higher protein needs are discussed to overcome this anabolic resistance and to maintain muscle mass as far as possible. Besides the total amount of protein consumed, the distribution, quality and timing in relation to physical exercise are considered relevant; however, deriving clear recommendations for clinical practice is still difficult as positive results of protein intake on muscle metabolism found in experimental trials cannot simply be transferred to everyday conditions and randomized controlled trials often failed to show improvements in muscular outcomes related to protein supplementation. The effectiveness of protein supplementation may depend on functional resources of the older persons and the habitual protein intake. There is still a need for studies with well-defined protocols and populations to further elucidate the role of protein in the prevention and treatment of sarcopenia.
Keywords: Amino acids; Anabolic resistance; Dietary intake; Muscle mass; Sarcopenia.