APRIL 13, 2017
American Journal of Clinical Nutrition
ShamsWhite MM, et al. –
Researchers assessing the impacts of dietary protein consumption alone and with calcium with or without vitamin D (Ca±D) on bone health measures in adults. Current evidence shows no adverse impacts of higher protein consumptions. Although there were positive trends on bone mineral density (BMD) at most bone sites, only the lumbar spine (LS) indicated moderate evidence to support benefits of higher protein consumption. Studies were heterogeneous, and confounding could not be excluded. High–quality, long–term studies are needed to clarify dietary protein’s role in bone health.
Methods
- Searches across 5 databases were conducted through October 2016 including randomized controlled trials (RCTs) and prospective cohort studies analyzing the impacts of “high versus low” protein consumption or dietary protein’s synergistic impact with the Ca±D intake on bone health outcomes.
- Two analysts independently conducted abstract and full–text screenings, information extractions, and risk of bias (ROB) evaluations.
- Strength of proof was rated by group consensus.
- Random–effects meta–analyses for results with ≥ 4 RCTs were performed.
Results
- In the systematic review, 16 RCTs and 20 prospective cohort studies were included.
- Overall ROB was medium.
- Moderate evidence recommended that higher protein consumption may have a protective affect lumbar spine (LS) bone mineral density (BMD) compared with lower protein consumption (net percentage change: 0.87%; 95% CI: 0.18%, 1.56%; I2: 0%; n= 4) however no impact on total hip (TH), femoral neck (FN), or total body BMD or bone biomarkers.
- Limited proof did not support an impact of protein with Ca±D on LS BMD, TH BMD, or forearm fractures; there was insufficient evidence for FN BMD and overall fractures.