EFFECT OF LEUCINE-RICH WHEY PROTEIN AS COMPARED TO SOY PROTEIN ON MUSCLE FUNCTION IN ELDERLY INDIVIDUALS WITH OSTEOPENIA. A FOUR MONTH RANDOMIZED STUDY
J.L. Mehlsen, S.B. Pedersen, K.I. Nørgaard, B.L. Langdahl, N. Møller, B. Richelsen
J Aging Res Clin Practice 2017;6:200-209
Objective: This investigation was conducted to determine whether dietary supplementation with a specific leucine-rich whey protein compound improves physical function and muscle strength in osteopenic elderly people compared to soy protein and placebo. Design, participants and setting: The study was a 16-week randomized single blinded placebo controlled intervention, including 47 women and 10 men from 60-85 years of age with osteopenia (T-score < -1.0 by dual energy X-ray absorptiometry scan). The subjects were assigned to three groups in 2:2:1 relations, daily receiving 1) whey (45.8 g protein including 6.14 g leucine (n=24)), 2) soy (45.9 g protein with 3.1 g leucine (n=23)), and 3) isocaloric placebo with maltodextrin (n=10). A home based resistance training protocol (3 x 45 min / week) was followed by all groups concurrently. The primary focus of the study was on the differences between the two protein groups. Measurements: Physical function was determined by six-minute walk (6MW) and four-meter gait speed (4MGS) tests as primary endpoints, and strength (maximum voluntary contraction) by hand grip, leg extension and -flexion as secondary endpoints. Results: 6MW increased significantly in the whey group compared to the soy group (4% as compared to 1% increment, P < 0.05) but no changes were found in 4MGS. There were no differences between any groups in other variables such as in the strength and balance tests. However, p-urate was significantly lower after whey protein as compared to soy (P < 0.01). Conclusions: Four months of leucine-rich whey protein supplementation and concurrent resistance training significantly increased the six-minute walk test in elderly individuals as compared to soy protein. However, whether this minor increment in the walk test is of clinical importance is unknown. There was no effect on the four-meter gait speed or any other secondary muscle function-related endpoints.
J.L. Mehlsen ; S.B. Pedersen ; K.I. Nørgaard ; B.L. Langdahl ; N. Møller ; B. Richelsen (2017): Effect of leucine-rich whey protein as compared to soy protein on muscle function in elderly individuals with osteopenia. A four month randomized study. The Journal of Aging Research and Clinical Practice (JARCP). http://dx.doi.org/10.14283/jarcp.2017.27