Despite protein being a critical component of bone structure, the impact of protein consumption on BMD has long been debated. Protein intake can increase the acid load in the blood, potentially leading to calcium being pulled out of the bone and into the blood to buffer this effect. This led many researchers to suggest that protein might reduce BMD, and this was seemingly supported by studies finding that increasing amounts of dietary protein led to increased excretion of calcium in the urine. However, current research suggests that dietary protein is associated with increased absorption of calcium from the intestine, which could account for the increased amount of calcium excreted in the urine.[1]
A 2017 meta-analysis of randomized controlled and observational trials by the National Osteoporosis Society found that higher intakes of protein may have a protective or neutral effect on BMD, depending on the site examined.[1] These results are supported by another 2017 meta-analysis of observational studies that found that higher protein intake (>0.8 g/kg/day) was associated with a reduced risk of hip fractures, with no indication of negative effects on BMD.[2]
References
- ^Shams-White MM, Chung M, Du M, Fu Z, Insogna KL, Karlsen MC, LeBoff MS, Shapses SA, Sackey J, Wallace TC, Weaver CMDietary protein and bone health: a systematic review and meta-analysis from the National Osteoporosis FoundationAm J Clin Nutr.(2017 Jun)
- ^Taylor C Wallace, Cara L FrankenfeldDietary Protein Intake above the Current RDA and Bone Health: A Systematic Review and Meta-AnalysisJ Am Coll Nutr.(2017 Aug)