Effects of Whey Proteins and Milk-basic Proteins on Bone Health Parameters: A Systematic Review and Meta-analysis of Randomized Clinical Trials

As a major public health concern worldwide, osteoporosis causes increased risks of bone fractures and decreases in bone mineral density. The present systematic review and meta-analysis aimed to determine the effect of whey protein and milk basic protein on bone health parameters.

In this study, a systematic review and meta-analysis of randomized clinical trials study was carried out. Online databases of PubMed, Scopus and Web of Science were searched up to 20 march 2023, using controlled terms (e.g., MESH) and text words for milk protein or whey and bone-health outcomes, including lumbar-bone mineral density, hip-bone mineral density, urinary N-terminal telopeptides of type I collagen, serum C-terminal telopeptides of type I collagen, osteocalcin and insulin-like growth factor 1 levels.

Outcomes were pooled as standard mean difference (SMD) and 95% confidence interval (CI) in a Random-effect meta-analysis model. Nine randomized clinical trials met the eligibility criteria and were selected for the final analysis. Analysis indicated significant decreases in N-terminal telopeptides of type I collagen [SMD, -0.89 nmol/mmol; CI, -1.69 to -0.10 %; p = 0.028] following supplementation with milk basic protein compared to the placebo group. Whey supplementation resulted in significant increases in insulin-like growth factor 1 [SMD, 3.55 nmol/l; 95% CI, 3.12 to 3.98%; P = 0.001; I2  = 58.1%; p = 0.092]. However, no significant mean differences were seen in lumbar-bone mineral density, hip-bone mineral density, serum C-terminal telopeptides of type I collagen and osteocalcin between the two groups.

Whey or milk basic protein supplementation may decrease N-terminal telopeptides of type I collagen and increase insulin-like growth factor 1, particularly when adults are supplemented for 12 w or longer; however, findings on lumbar-bone mineral density, hip-bone mineral density, serum C-terminal telopeptides of type I collagen and osteocalcin are inconclusive.