Nutritionpreliminary · human data
Extra protein added nothing measurable to exercise's bone benefits
In the few trials that combined protein supplements with exercise in middle-aged and older adults, bone mineral content barely moved compared with exercise alone. The evidence on bone density was too thin to call either way.
For you: If you take protein hoping it strengthens bones as well as muscle, the bone part remains unproven in either direction.
What it shows: Treat this as an open question rather than a firm no: only 4 small trials could be pooled, they disagreed with each other, and the reviewers rate the certainty of the evidence as low. Bigger and longer studies are needed before anyone can say protein does nothing extra for bone.Meta-analysis · Osteoporos Int