title: Dietary protein and bone health: a systematic review and meta-analysis from the National Osteoporosis Foundation.
abstract: Background: Considerable attention has recently focused on dietary protein's role in the mature skeleton, prompted partly by an interest in nonpharmacologic approaches to maintain skeletal health in adult life.Objective:The aim was to conduct a systematic review and meta-analysis evaluating the effects of dietary protein intake alone and with calcium with or without vitamin D (Ca±D) on bone health measures in adults.Design:Searches across 5 databases were conducted through October 2016 including randomized controlled trials (RCTs) and prospective cohort studies examining1) the effects of "high versus low" protein intake or2) dietary protein's synergistic effect with Ca±D intake on bone health outcomes. Two investigators independently conducted abstract and full-text screenings, data extractions, and risk of bias (ROB) assessments. Strength of evidence was rated by group consensus. Random-effects meta-analyses for outcomes with ≥4 RCTs were performed.Results:Sixteen RCTs and 20 prospective cohort studies were included in the systematic review. Overall ROB was medium. Moderate evidence suggested that higher protein intake may have a protective effect on lumbar spine (LS) bone mineral density (BMD) compared with lower protein intake (net percentage change: 0.52%; 95% CI: 0.06%, 0.97%,I2: 0%;n= 5) but no effect on total hip (TH), femoral neck (FN), or total body BMD or bone biomarkers. Limited evidence did not support an effect of protein with Ca±D on LS BMD, TH BMD, or forearm fractures; there was insufficient evidence for FN BMD and overall fractures.Conclusions:Current evidence shows no adverse effects of higher protein intakes. Although there were positive trends on BMD at most bone sites, only the LS showed moderate evidence to support benefits of higher protein intake. 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. This trial was registered at www.crd.york.ac.uk as CRD42015017751.
authors.affiliation: Department of Public Health and Community Medicine, School of Medicine, and.|Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA.
authors.forename: Marissa M
authors.identifier: 0000-0002-7824-4545
authors.initials: MM
authors.lastname: Shams-White
authors.affiliation: Department of Public Health and Community Medicine, School of Medicine, and.
authors.forename: Mei
authors.identifier: 0000-0002-5583-2870
authors.initials: M
authors.lastname: Chung
authors.affiliation: Department of Public Health and Community Medicine, School of Medicine, and.|Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA.
authors.forename: Mengxi
authors.initials: M
authors.lastname: Du
authors.affiliation: Department of Public Health and Community Medicine, School of Medicine, and.
authors.forename: Zhuxuan
authors.initials: Z
authors.lastname: Fu
authors.affiliation: Yale Bone Center at the Yale School of Medicine, Yale University, New Haven, CT.
authors.forename: Karl L
authors.initials: KL
authors.lastname: Insogna
authors.affiliation: Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA.
authors.forename: Micaela C
authors.initials: MC
authors.lastname: Karlsen
authors.affiliation: Skeletal Health and Osteoporosis Center and Bone Density Unit, Harvard Medical School, Boston, MA.|Endocrine, Diabetes and Hypertension Division, Brigham and Women's Hospital, Boston, MA.
authors.forename: Meryl S
authors.initials: MS
authors.lastname: LeBoff
authors.affiliation: Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ.
authors.forename: Sue A
authors.identifier: 0000-0002-3128-2325
authors.initials: SA
authors.lastname: Shapses
authors.affiliation: Department of Public Health and Community Medicine, School of Medicine, and.|Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA.
authors.forename: Joachim
authors.initials: J
authors.lastname: Sackey
authors.affiliation: National Osteoporosis Foundation, Arlington, VA; taylor.wallace@me.com.|Department of Nutrition and Food Studies, George Mason University, Fairfax, VA; and.
authors.forename: Taylor C
authors.initials: TC
authors.lastname: Wallace
authors.affiliation: Department of Nutrition Science, Women's Global Health Institute, Purdue University, West Lafayette, IN.
authors.forename: Connie M
authors.initials: CM
authors.lastname: Weaver
mesh_terms: D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D002118:Calcium / Q000494:pharmacology / Q000627:therapeutic use; D002136:Calcium, Dietary / Q000494:pharmacology / Q000627:therapeutic use; D004044:Dietary Proteins / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D050723:Fractures, Bone / Q000378:metabolism / Q000517:prevention & control; D006801:Humans; D008159:Lumbar Vertebrae / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010024:Osteoporosis / Q000378:metabolism / Q000517:prevention & control*; D014807:Vitamin D / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D050071:Bone Density Conservation Agents; D002136:Calcium, Dietary; D004044:Dietary Proteins; D014807:Vitamin D; D002118:Calcium
keywords: bone density; bone health; diet; osteoporosis; protein