Supplementing breakfast with a vitamin D and leucine-enriched why protein medical nutrition drink enhances postprandial muscle protein synthesis and muscle mass in healthy older men. J Nutr, 2017.
To investigate the acute effect of supplementing breakfast with a vitamin D and leucine-enriched whey protein medical nutrition drink on postprandial muscle protein synthesis (primary outcome) and longer-term effect body composition (appendicular and leg lean mass), physical performance, dietary intake, nutritional biomarkers, and postprandial metabolic response in healthy older adults.
Sarcopenia, the age-related loss of skeletal muscle mass and function, is partly the result of an impaired activation of postprandial muscle protein synthesis by anabolic stimuli, i.e., amino acids and insulin. A promising strategy to help older adults preserve or build muscle mass is to optimise muscle anabolism through providing an adequate amount of high-quality protein at each meal.
The PROMOTION study was a randomised, placebo-controlled, double-blind, parallel-group, single-centre trial. Participants were recruited by the study team of the muscle metabolic adaptation group at the Unit of Human Nutrition, University of Auvergne, Clermont-Ferrand, France.
Twenty-four healthy adult men aged >65 y with a BMI between 20 and 30 kg/m2were eligible for inclusion.
Participants were randomly assigned 1:1 to receive a vitamin D and leucine-enriched whey protein medical nutrition drink, containing 20g whey protein, 3g total leucine, including protein-bound and free L-leucine, 9g carbohydrates, 3g fat, and 800 IU cholecalciferol (vitamin D3) with an energy value of 628kJ (or a non-caloric placebo product with similar taste and appearance before breakfast for 6 weeks.
Mixed muscle protein fractional synthesis rate (FSR) was measured at week 0 in the basal and postprandial state, after study product intake with a standardised breakfast with the use of l-[2H5]-phenylalanine tracer methodology.
The longer-term effect of the medical nutrition drink on body composition was evaluated by dual-energy X-ray absorptiometry measurement at weeks 0 and 6.
Supplementing breakfast with a vitamin D and leucine-enriched whey protein medical nutrition drink stimulated postprandial muscle protein synthesis and increased muscle mass after 6 weeks of intervention in healthy older adults, and may therefore be a way to support muscle preservation in older people.
Please read the full publication in the Journal of Nutrition here.