A new study published in the Journal of Nutrition suggest consuming high-quality proteins may help delay the onset of sarcopenia, an age-related decline in muscle mass and strength.
In a double-blind controlled clinical trial, researchers from the University of Texas Medical Branch at Galveston, compared two groups of men ages 55-75, consuming two high-quality proteins, after one hour of resistance exercise. While one group was provided with a 30g blend of soy and dairy proteins (25% isolated DuPoint Danisco SUPRO Soy protein, 50% caseinate, 25% whey protein isolate), the control group was supplied with 30g of a single protein source (whey protein isolate).
To monitor any “breakdown and synthesis of muscle tissue using stable isotope methods,” muscle biopsies were taken before and up to 5 hours after resistance exercising. At the end of the trial, researchers found the “soy-dairy protein blend induced amino acid delivery to muscle tissue, muscle protein synthesis and activated a recognized pathway that initiates muscle protein turnover.”
Similar results were also found in older adults that were given 30 g of the soy-dairy protein or whey protein after exercise.
“Our data provide[s] additional support for the use of targeted nutritional interventions to overcome a critical condition of aging, anabolic resistance, to counteract sarcopenia,” said Blake B. Rasmussen, Ph.D., chair, department of Nutrition & Metabolism at the University of Texas Medical Branch and lead researcher of the study. “Research conducted in both young and older subjects demonstrates the importance of delivering the amino acid leucine to promote anabolic signaling and skeletal muscle protein synthesis. In this study, the two groups were not matched for leucine content but both groups received enough leucine to exceed the minimum threshold to shift protein turnover into an anabolic state.”
Although diet and exercising are two important factors for maintaining muscle health, researchers have recently found that each “becomes blunted as we age.”
Posted on WholeFoods Magazine Online, 12/9/2016