ST. LOUIS, Jan. 24, 2013 – A new study published in The Journal of Nutrition demonstrates the benefits of consuming a protein blend for muscle protein synthesis after exercise. This study is a first-of-its-kind, conducted by researchers at the University of Texas Medical Branch, and utilizes the proteins from soy, whey and casein consumed after an acute bout of resistance exercise. These proteins have complementary amino acid profiles and different digestion rates (amino acid release profiles). The results demonstrate prolonged delivery of amino acids to muscles and extended muscle protein synthesis when subjects consumed the blend, compared to a single source of protein alone.
"Sources of high-quality protein contain all the essential amino acids and have individual characteristics thought to offer a unique advantage for muscle growth," said Blake Rasmussen, Ph.D., interim chair, Department of Nutrition & Metabolism and principal investigator of the study. "This is the first study to test the effects of combining soy with the dairy proteins, whey and casein, for promotion of lean body mass gain."
The composition of the blend used in the current study was based on results from a recently published pre-clinical study that demonstrated enhanced postprandial skeletal muscle protein synthesis in rats compared to another blend of soy or whey protein sources alone. This human clinical study for the first time shows that a soy-dairy protein blend (25 percent SUPRO® isolated soy protein, 25 percent whey protein isolate and 50 percent caseinate) is capable of stimulating muscle growth to a similar extent as whey protein through an elevation in muscle protein synthesis and muscle cell growth signaling. In addition, the blend extended the anabolic window (i.e., prolonged increase in the rate of muscle protein synthesis from rest) for a longer amount of time than whey alone.
The beverages provided approximately 20 grams of protein from either the soy-dairy blend or whey protein and contained similar amounts of leucine, a key amino acid involved in muscle cell signaling pathways that regulate muscle protein synthesis rates. The beverages were consumed following high-intensity leg resistance exercise. Multiple leg muscle samples were collected from each subject to determine changes in muscle protein synthesis over time (at rest and 3 and 5 hours after exercise). Nineteen healthy, young adults participated in the randomized, double blind trial.
"Previous research examines only single sources of proteins and does not match the protein sources for leucine content, a branched chain amino acid with anabolic effects, thought to trigger muscle protein synthesis. Results from our study with matched leucine indicate the soy-dairy protein blend stimulated muscle synthesis during the early recovery period as well as into the later post-exercise period, compared to the single protein treatment, whey, which only increased muscle synthesis from rest into the early recovery period," said Paul Reidy, lead investigator on the study.
Proteins from milk (casein and whey), soy, beef and egg are effective in stimulating post-exercise muscle protein synthesis. This study demonstrates that consumption of a beverage made with a soy-dairy protein blend following exercise is capable of prolonging amino acid delivery to muscles, muscle cell signaling and protein synthesis in human skeletal muscle. This extension of the anabolic window may also be important for the aging muscle.
"No research on blends of proteins from different sources and their effects on muscle protein synthesis has been done, to-date. Muscle health is of great concern to not only young and active individuals like the ones in this study but also to the aging population. The role of protein for muscle health is a key area of interest for our company, " said Ratna Mukherjea, Ph.D., Nutrition Science team lead at Solae/DuPont Nutrition & Health. "This publication expands on results indicating the beneficial effects of consuming blends shared at numerous scientific meetings in 2012."
For more information on the study, the following is a link to the study on the Journal of Nutrition site. http://jn.nutrition.org/content/early/recent
Solae™ soy-based ingredient solutions help create nutritious, great-tasting products with a unique combination of functional, nutritional, economical and sustainable benefits. Solae, LLC, originally a DuPont joint venture, was fully acquired by DuPont on May 1, 2012, and is now part of DuPont Nutrition & Health, a world leader in specialty food ingredients. For more information, visit www.Solae.com, or follow us on Twitter at www.Twitter.com/SolaeLLC, Facebook at www.Facebook.com/SolaeLLC, and LinkedIn at www.linkedin.com/company/Solae-LLC.
DuPont Nutrition & Health addresses the world's challenges in food by offering a wide range of sustainable, bio-based ingredients and advanced microbial diagnostic solutions to provide safer, healthier and more nutritious food. Through close collaboration with customers, DuPont combines knowledge and experience with a passion for innovation to deliver unparalleled customer value to the marketplace.
DuPont (NYSE: DD) has been bringing world-class science and engineering to the global marketplace in the form of innovative products, materials, and services since 1802. The company believes that by collaborating with customers, governments, NGOs, and thought leaders we can help find solutions to such global challenges as providing enough healthy food for people everywhere, decreasing dependence on fossil fuels, and protecting life and the environment. For additional information about DuPont and its commitment to inclusive innovation, please visit www.dupont.com.
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.