Whey Protein May Help Build Muscle in the Elderly
Lee Swanson Research Update
A supplement containing whey protein can boost the building of muscle in the elderly, according to a study published in Nutrition Research.
"It is recognized that both whey protein (WY) and essential amino acids (EAA) are stimuli for muscle protein anabolism (synthesis)," Research stated. "The aim of the present study was to determine if the effects of WY ingestion on muscle protein accrual in elderly persons are due solely to its constituent EAA content."
Fifteen elderly people took part in the trial, which found improvements in the levels of phenylalanine, a measure of muscle protein accumulation. "This finding may have practical implications for the formulation of nutritional supplements to enhance muscle anabolism in older individuals," wrote lead author Christos Katsanos from Arizona State University.
The participants (average age 65.7) received a bolus (dose) containing whey protein (WY, 15 grams), the constituent essential amino acids (EAA, 6.72 grams), or the non-essential amino acids (NEAA, 7.57 grams). During the 3.5 hours that followed ingestion of the bolus, the researchers measured the phenylalanine balance in the subjects.
Katsanos and his co-workers report that only subjects in the whey group experienced improvements in the phenylalanine balance, from -216 to -105 nanomoles per minute per kilograms of lean leg mass. In the essential and non-essential amino acid groups, phenylalanine balance changed from -203 to -172, and from -203 to -204 nanomoles per minute per kilograms of lean leg mass, respectively.
"The most important finding of this study is that WY, at least in the amount ingested in this study, results in greater anabolic effect in elderly persons than its EAA," wrote the researchers. "Therefore, this suggests that WY ingestion improves skeletal muscle protein accrual through mechanisms that are beyond those attributed to its EAA content."
Nutrition 28(10):651-658, 2008