Effect of Whey Protein Supplementation on Plasma Bone-Resorption Biomarker in Post-Menopausal Women Submitted to Physical Exercise Training

To evaluate the additional effect of whey protein supplementation (WPS) to the physical-exercise training on bone resorption in postmenopausal women. In a prospective, controlled study, 38 postmenopausal women aged 50 to 70 years, were randomized into two groups: with WPS (n = 19) and without WPS (n = 19, control) intervention. The study included amenorrheic women (above 12 months) with normal bone mineral density (T-score ≥ −1.0 SD) not taken bone-related medicines, and practitioners of a physical exercise protocol involving combined walking/jogging and academy/resistance exercises performed under professional supervising, three times a week. Together, there was a weekly dietary counseling along with a daily supplementation of either 25 g of protein (WPS) or placebo. Food intake (24-hour recall), anthropometric, general biochemistry, plasma hormones and bone resorption marker: serum C-terminal cross-linked N-telopeptides of type-I collagen (s-CTX) assessments were undertaken at baseline and after 20-wk intervention. Statistical analysis of the data (P < 0.05) was performed by using a time-repeated measures (ANOVA) followed by the Tukey multiple comparison test adjusted for group x moment interaction, or by gamma distribution (asymmetric variables). The groups were anthropometric and biochemical homogeneous, at baseline and after the intervention. Both groups increased similarly the intake of energy and lipids. However, only WPS significantly increased the intake of protein, calcium, phosphates and magnesium, as well as leucine, isoleucine and valine. From a similar baseline plasma values of s-CTX, calcium, phosphorus, alkaline phosphatase and parathormone, only s-CTX responded significantly to the intervention, being reduced in both groups (-34% and −15.2%), statistically significant in the control(non-WPS) group (P = 0.016). The reduced plasma marker of bone resorption marker was observed in post-menopause women submitted to a 20-wk lifestyle-modification protocol with physical exercises, independently to the whey protein supplementation. Clinical trial (REBEC): RBR-7KD97. Brazilian foundations CNPq and CAPES.