Dietary protein intake and risk of osteoporotic hip fracture in elderly residents of Utah. A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. Study of Osteoporotic Fractures Research Group. Identification of a dietary pattern prospectively associated with bone mass in Australian young adults. The Relation between Dietary Protein, Calcium and Bone Health in Women: Results from the EPIC-Potsdam Cohort Calcium intake influences the association of protein intake with rates of bone loss in elderly men and women. Protein intake: effects on bone mineral density and the rate of bone loss in elderly women. Calcium intake in health maintenance – a systematic review Biomarker-calibrated protein intake and bone health in the Women's Health Initiative clinical trials and observational study. Calcium supplementation prevents seasonal bone loss and changes in biochemical markers of bone turnover in elderly New England women: a randomized placebo-controlled trial. Nutritional factors that influence change in bone density and stress fracture risk among young female cross-country runners. A diet high in protein, dairy, and calcium attenuates bone loss over twelve months of weight loss and maintenance relative to a conventional high-carbohydrate diet in adults. Protein consumption and bone fractures in women. Whey Protein Supplementation and Higher Total Protein Intake Do Not Influence Bone Quantity in Overweight and Obese Adults Following a 36-Week Exercise and Diet Intervention. Effects of food groups and dietary nutrients on bone loss in elderly Chinese population [Optimization of calcium intake for the prevention of osteoporosis and osteoporotic fractures: a review of the evidence]. Areal and volumetric bone mineral density and geometry at two levels of protein intake during caloric restriction: a randomized, controlled trial. Association of protein intake with bone mineral density and bone mineral content among elderly women: The OSTPRE fracture prevention study Dietary factors and the incidence of hip fracture in middle-aged Norwegians. A prospective study. Correlates of Quantitative Ultrasound in the Women’s Healthy Lifestyle Project
 Comparison of 2 weight-loss diets of different protein content on bone health: a randomized trial. Long-term protein intake and dietary potential renal acid load are associated with bone modeling and remodeling at the proximal radius in healthy children. Effect of dietary protein supplements on calcium excretion in healthy older men and women. Diets higher in dairy foods and dietary protein support bone health during diet- and exercise-induced weight loss in overweight and obese premenopausal women.
UNLABELLED The role of protein intake in osteoporosis is unclear . In a case-control study in Utah ( n = 2501 ) , increasing level of protein intake was associated with a decreased risk of hip fracture in men and women 50 - 69 years of age but not in those 70 - 89 years of age . Protein intake may be important for optimal bone health . INTRODUCTION Protein is an important component of bone , but the role of dietary protein intake in osteoporosis and fracture risk remains controversial . MATERIAL AND METHODS The role of dietary protein intake in osteoporotic hip fracture was evaluated in a statewide case-control study in Utah . Patients , 50 - 89 years of age , with hip fracture ( cases ) were ascertained through surveillance of 18 Utah hospitals during 1997 - 2001 . Age- and gender-matched controls were r and omly selected . Participants were interviewed in their place of residence , and diet was assessed using a picture-sort food frequency question naire previously reported to give a useful measure of usual dietary intake in the elderly Utah population . The association between  protein intake  and risk of hip fracture was examined across quartiles of protein intake and stratified by age group for 1167 cases ( 831 women , 336 men ) and 1334 controls ( 885 women , 449 men ) . RESULTS In logistic regression analyses that controlled for gender , body mass index , smoking status , alcohol use , calcium , vitamin D , potassium , physical activity , and estrogen use in women , the odds ratios ( OR ) of hip fracture decreased across increasing quartiles of total protein intake for participants 50 - 69 years of age ( OR : 1.0 [ reference ] ; 0.51 [ 95 % CI : 0.30 - 0.87 ] ; 0.53 [ 0.31 - 0.89 ] ; 0.35 [ 0.21 - 0.59 ] ; p < 0.001 ) . No similar associations were observed among participants 70 - 89 years of age . Results from analyses stratified by low and high calcium and potassium intake did not differ appreciably from the results presented above . CONCLUSION Higher total protein intake was associated with a reduced risk of hip fracture in men and women 50 - 69 years of age but not in men and women 70 - 89 years of age . The association between  dietary protein intake  and risk of hip fracture may be modified by age . Our study supports the hypothesis that adequate dietary protein is important for optimal bone health in the elderly 50 - 69 years of age BACKGROUND Different sources of dietary protein may have different effects on bone metabolism . Animal foods provide predominantly acid precursors , whereas protein in vegetable foods is accompanied by base precursors not found in animal foods . Imbalance between dietary acid and base precursors leads to a chronic net dietary acid load that may have adverse consequences on bone . OBJECTIVE We wanted to test the hypothesis that a high dietary ratio of animal to vegetable foods , quantified by protein content , increases bone loss and the risk of fracture . DESIGN This was a prospect i ve cohort study with a mean ( + /-SD ) of 7.0+/-1.5 y of follow-up of 1035 community-dwelling white women aged > 65 y.  Protein intake  was measured by using a food-frequency question naire and  bone mineral density was measured by dual-energy X-ray absorptiometry . RESULTS Bone mineral density was not significantly associated with the ratio of animal to vegetable protein intake . Women with a high ratio had a higher rate of bone loss at the femoral neck than did those with a low ratio ( P = 0.02 ) and a greater risk of hip fracture ( relative risk = 3.7 , P = 0.04 ) . These associations were unaffected by adjustment for age , weight , estrogen use , tobacco use , exercise , total calcium intake , and total protein intake . CONCLUSIONS Elderly women with a high dietary ratio of animal to vegetable protein intake  have more rapid femoral neck bone loss and a greater risk of hip fracture than do those with a low ratio . This suggests that an increase in vegetable protein intake and a decrease in animal protein intake may decrease bone loss and the risk of hip fracture . This possibility should be confirmed in other prospect i ve studies and tested in a r and omized trial BACKGROUND Relatively little is known about the relations between dietary patterns and bone health in adolescence , which is a period of substantial bone mass accrual . OBJECTIVES We derived dietary patterns that were hypothesized to be related to bone health on the basis of their protein , calcium , and potassium contents and investigated their prospect i ve associations with bone mineral density ( BMD ) , bone area , and bone mineral content ( BMC ) in a cohort of young adults . DESIGN The study included 1024 young adults born to mothers who were participating in the Western Australian Pregnancy Cohort ( Raine ) Study .  Dietary information was obtained from food-frequency question naires at 14 and 17 y of age . Dietary patterns were characterized according to protein , calcium , and potassium intakes with the use of reduced-rank regression . BMD , bone area , and BMC were estimated with the use of a total body dual-energy X-ray absorptiometry scan at 20 y of age . RESULTS We identified 2 major dietary patterns . The first pattern was positively correlated with intakes of protein , calcium , and potassium and had high factor loadings for low-fat dairy products , whole grains , and vegetables . The second pattern was positively correlated with protein intake but negatively correlated with intakes of calcium and potassium and had high factor loadings for meat , poultry , fish , and eggs . After adjustment for anthropometric , sociodemographic , and lifestyle factors , a higher z score for the first pattern at 14 y of age was positively associated with BMD and BMC at 20 y of age [ differences : 8.6 mg/cm(2 ) ( 95 % CI : 3.0 , 14.1 mg/cm(2 ) ) and 21.9 g ( 95 % CI : 6.5 , 37.3 g ) , respectively , per SD increase in z score ] . The z score for this same pattern at 17 y of age was not associated with bone outcomes at 20 y of age . The second pattern at 14 or 17 y of age was not associated with BMD , BMC , or bone area . CONCLUSIONS A dietary pattern characterized by high intakes of protein , calcium , and potassium in midadolescence was associated with higher BMD and BMC at 20 y of age . Our results indicate that high consumption of low-fat dairy products , whole grains , and vegetables in adolescence are associated with beneficial effects on bone development Background / Aims : The role of dietary protein in bone health is controversial . The objective of the present study was to examine the association between protein intake , dietary calcium , and bone structure measured by broadb and ultrasound attenuation ( BUA ) . Methods : Our analysis includes 8,178 female study participants of the European Prospect i ve Investigation into Cancer and Nutrition ( EPIC ) Potsdam Study . Ultrasound bone measurements were performed on the right os calcis , and BUA was determined . Dietary intake was assessed by a st and ardized food frequency question naire . We applied linear regression models to estimate the association between dietary protein and BUA . Results : After multivariate adjustment , high intake of animal protein was associated with decreased BUA values ( β = –0.03 ; p = 0.010 ) whereas high vegetable protein intake was related to an increased BUA ( β = 0.11 ; p = 0.007 ) . The effect of dietary animal protein on BUA was modified by calcium intake . Conclusion : High consumption of protein from animal origin may be unfavourable , whereas a higher vegetable protein intake may be beneficial for bone health . Our results strengthen the hypothesis that high calcium intake combined with adequate protein intake based on a high ratio of vegetable to animal protein may be protective against osteoporosis BACKGROUND There is currently no consensus on the effect of dietary protein intake on the skeleton , but there is some indication that low calcium intakes adversely influence the effect of dietary protein on fracture risk . OBJECTIVE The objective of the present study was to determine whether supplemental calcium citrate malate and vitamin D influence any associations between  protein intake and change in bone mineral density ( BMD ) . DESIGN Associations between protein intake and change in BMD were examined in 342 healthy men and women ( aged > or = 65 y ) who had completed a 3-y , r and omized , placebo-controlled trial of calcium and vitamin D supplementation . Protein intake was assessed at the midpoint of the study with the use of a food-frequency question naire and  BMD  was assessed every 6 mo by dual-energy X-ray absorptiometry . RESULTS The mean ( + /-SD ) protein intake of all subjects was 79.1 + /- 25.6 g/d and the mean total calcium intakes of the supplemented and placebo groups were 1346 + /- 358 and 871 + /- 413 mg/d , respectively . Higher protein intake was significantly associated with a favorable 3-y change in total-body BMD in the supplemented group ( in a model containing terms for age , sex , weight , total energy intake , and dietary calcium intake ) but not in the placebo group . The pattern of change in femoral neck BMD with increasing protein intake in the supplemented group was similar to that for the total body . CONCLUSION Increasing protein intake may have a favorable effect on change in BMD in elderly subjects supplemented with calcium citrate malate and vitamin BACKGROUND The role of dietary protein in bone metabolism is controversial . OBJECTIVE We investigated the associations of dietary protein intake with baseline bone mineral density ( BMD ) and the rate of bone loss over 3 y in postmenopausal elderly women . DESIGN Women aged 65 - 77 y ( n = 489 ) were enrolled in an osteoporosis intervention trial . We studied the associations of protein intake as a percentage of energy with baseline BMD and the rate of bone loss in 96 women in the placebo group ( n = 96 ) . We also examined the effect of the interaction of dietary  calcium  intake with protein intake on BMD . RESULTS In the cross-sectional study , a higher intake of protein was associated with higher BMD . BMD was significantly higher ( P < 0.05 ) in the spine ( 7 % ) , midradius ( 6 % ) , and total body ( 5 % ) in subjects in the highest quartile of protein intake than in those in the lower 2 quartiles . This positive association was seen in women with calcium intakes > 408 mg/d . There was no significant effect of protein intake on hip BMD . In the longitudinal study of the placebo group , there was no association between protein intake and the rate of bone loss . CONCLUSIONS The highest quartile of protein intake (: 72 g/d ) was associated with higher BMD  in elderly women at baseline only when the calcium intake exceeded 408 mg/d . In the longitudinal study , no association was seen between protein intake and the rate of bone loss , perhaps because the sample size was too small or the follow-up period of 3 y was not long enough to detect changes Background Calcium ( Ca ) is an essential nutrient for the human body . Despite lively research , there is uncertainty about Ca requirements in terms of desirable health outcomes including an upper intake level above which the potential for harm increases . Objectives The aim was to conduct a review to up date requirements and desirable or harmful health effects of Ca on the current scientific evidence . Methods We search ed Medline and Swemed from January 2000 to December 2011 and included all systematic review s that reported Ca supplementation or usual Ca intake on health outcomes . Meta-analyses , r and omized clinical trials and cohort studies were included in the second search between May 2009 and March 2011 and an additional search covering studies till the end of 2011 . This review concentrated on studies reporting independent effects of Ca , although a few recent trials report sole effects of Ca on health outcomes , most trials use Ca in combination with vitamin D vs. placebo . Results In total , we review ed 38 studies addressing the effects of Ca on bone , pregnancy-related outcomes , cancers , cardiovascular outcomes , obesity , and mortality .  There was a lot of heterogeneity in the study protocol s , which made it difficult to draw any strong conclusions . According to the literature , high Ca intake seems to have a small positive effect on bone mineral content ( BMC ) or bone mineral density ( BMD ) in children and postmenopausal women . We did not find any consistent evidence on the effects of Ca on bone health in premenopausal women or men . Also , the evidence that Ca supplementation reduces fracture incidence is scarce and inconsistent . Maternal diet may influence the peak bone mass of offspring but more studies are required . There was no overall effect of Ca intake on cancers . Ca was associated with a decreased risk of breast cancer and a slightly increased risk of prostate cancer in two of the three studies . No associations were found with other cancers . We found no consistent association between cardiovascular outcomes and  Ca  intake except for blood pressure . A small decrease of 2–4 mmHg in systolic blood pressure was found in pregnant and in hypertensive subjects with Ca supplementation . Review ed studies did not show consistent evidence relating Ca intake to either mortality or obesity . Conclusion Based on this evidence , there is no need to change the Nordic recommendations for Ca intake . However , due to heterogeneity in the studies it is difficult to interpret the results and provide single summary statement BACKGROUND The effects of dietary protein on bone health are controversial . OBJECTIVE We examined the relation between protein intake with fracture and  bone mineral density ( BMD )  within the Women 's Health Initiative ( WHI ) . DESIGN This prospect i ve analysis included 144,580 women aged 50 - 79 y at baseline in the WHI clinical trials ( CTs ) and observational study ( OS ) that recruited participants in 1993 - 1998 with follow-up through 2011 . Self-reported clinical fractures were collected semiannually through the original end of the trials ( WHI CTs ) and annually ( WHI OS ) by question naires . Hip fracture was adjudicated by a central review of radiology reports . BMDs for total body , hip , and spine were measured at baseline and 3 and 6 y in 9062 women at 3 WHI clinics by using dual-energy X-ray absorptiometry .  Protein intake was assessed via food-frequency question naire and calibrated by using biomarkers of energy and protein intakes . Associations between protein intake and fracture were estimated by using Cox proportional hazards regression , and the relation between protein intake and BMD was estimated by using linear regression . RESULTS Median biomarker-calibrated protein intake was 15 % of energy intake . Per 20 % increase in calibrated protein intake ( percentage of energy ) , there was no significant association with total fracture ( HR : 0.99 ; 95 % CI : 0.97 , 1.02 ) or hip fracture ( HR : 0.91 ; 95 % CI : 0.84 , 1.00 ) , but there was an inverse association with forearm fracture ( HR : 0.93 ; 95 % CI : 0.88 , 0.98 ) . Each 20 % increase in calibrated protein intake was associated with a significantly higher BMD for total body ( mean 3-y change : 0.003 g/cm² ; 95 % CI : 0.001 , 0.005 g/cm² ) and hip ( mean 3-y change : 0.002 g/cm² ; 95 % CI : 0.001 , 0.004 g/cm² ) . CONCLUSIONS Higher biomarker-calibrated protein intake within the range of usual intake was inversely associated with forearm fracture and was associated with better maintenance of total and hip BMDs . These data suggest higher protein intake is not detrimental to bone health in postmenopausal women Elderly women are at increased risk for bone loss and fractures . In previous cross-sectional and longitudinal studies of women residing in northern latitudes , bone loss was most pronounced during winter months and in those consuming less than 1 g calcium per day . In this study we sought to test the hypothesis that calcium supplementation by either calcium carbonate or dietary means would prevent seasonal bone loss and preserve bone mass . Sixty older postmenopausal women without osteoporosis were r and omized to one of three treatment arms : Dietary milk supplementation ( D-4 glasses of milk/day ) , Calcium carbonate ( CaCO3 - 1000 mg/day in two divided doses ) , or placebo ( P ) . After 2 yr , placebo-treated women consumed a mean of 683 mg/day of calcium and lost 3.0 % of their greater trochanteric ( GT ) bone mineral density ( BMD ) ( P < 0.03 vs. baseline ) ; Dietary supplemented women averaged a calcium intake of 1028 mg/day and sustained minimal loss from the GT ( -1.5 % ; P = 0.30 ) , whereas CaCO3-treated women ( total Ca intake , 1633 mg/day ) suffered no bone loss from the GT and showed a significant increase in spinal and femoral neck BMD ( P < 0.05 ) . Femoral bone loss occurred exclusively during the two winters of the study ( i.e. total loss , -3.2 % ; P < 0.02 in placebo-treated women ) with virtually no change in GT BMD during summer . Serum 25-OH vitamin D declined by more than 20 % ( P < 0.001 ) in all groups during the winter months but returned to baseline in summer ; PTH levels rose approximately 20 % ( P < 0.001 ) during winter but did not return to baseline during the summers . Urine N-telopeptide and osteocalcin levels increased significantly but only in the P-treated women and only during winter . Serum insulin growth factor binding protein 4 , an inhibitory insulin growth factor binding protein , rose 15 % ( P < 0.03 ) from summer to winter , but this increase was significant only in those women consuming < 1000 mg/day of calcium . By multivariate analysis , total calcium intake was the strongest predictor of bone loss from the hip . Urinary N-telopeptide also closely correlated with GT BMD but only during winter ( P = 0.003 ) . We conclude that calcium supplementation prevents bone loss  in elderly women by suppressing bone turnover during the winter when serum 25-OH vitamin D declines and serum PTH increases . The precise amount of calcium necessary to preserve BMD in elderly women requires further studies , although in this study , at least 1000 mg/day of supplemental calcium was adequate prophylaxis against femoral bone loss OBJECTIVE To identify nutrients , foods , and dietary patterns associated with stress fracture risk and changes in bone density among young female distance runners . DESIGN AND SETTING Two-year , prospect i ve cohort study . Observational data were collected in the course of a multicenter r and omized trial of the effect of oral contraceptives on bone health . PARTICIPANTS One hundred and twenty-five female competitive distance runners ages 18 - 26 years . ASSESSMENT OF RISK FACTORS Dietary variables were assessed with a food frequency question naire . MAIN OUTCOME MEASUREMENTS Bone mineral density and content ( BMD/ BMC ) of the spine , hip , and total body were measured annually by dual x-ray absorptiometry ( DEXA ) .  Stress fractures were recorded on monthly calendars , and had to be confirmed by radiograph , bone scan , or magnetic resonance imaging . RESULTS Seventeen participants had at least one stress fracture during follow-up . Higher intakes of calcium , skim milk , and dairy products were associated with lower rates of stress fracture . Each additional cup of skim milk consumed per day was associated with a 62 % reduction in stress fracture incidence ( P < .05 ) ; and a dietary pattern of high dairy and low fat intake was associated with a 68 % reduction ( P < .05 ) . Higher intakes of skim milk , dairy foods , calcium , animal protein , and potassium were associated with significant ( P < .05 ) gains in whole-body BMD and BMC . Higher intakes of calcium , vitamin D , skim milk , dairy foods , potassium , and a dietary pattern of high dairy and low fat were associated with significant gains in hip BMD . CONCLUSIONS In young female runners , low-fat dairy products and the major nutrients in milk ( calcium , vitamin D , and protein ) were associated with greater bone gains and a lower stress fracture rate . Potassium intake was also associated with greater gains in hip and whole-body BMD Weight loss causes  bone mineral loss .  Higher protein diets continue to be criticized for further potential harmful bone effects , including elevated urinary calcium , but may promote bone health if protein sources include dairy . Overweight middle-aged subjects ( n = 130 , 59 males ) were r and omized to a diet providing 1.4 g.kg(-1).d(-1 ) protein and 3 daily servings of dairy ( PRO ) or 0.8 g.kg(-1).d(-1 ) protein and 2 daily servings of dairy ( CARB ) for 4 mo of weight loss plus 8 mo of weight maintenance . Diets prescribed 6276 kJ/d for females and 7113 kJ/d for males . Bone mineral content and density ( BMD ) for whole body ( WB ) , lumbar spine ( LS ) and total hip ( TH ) were measured using dual X-ray absorptiometry , and dietary intake using 3-d weighed food records . Urinary calcium was measured using 24-h collection at 0 and 8 mo for a sub sample ( n = 42 ) . Participants lost body weight ( mean , 95 % CI ) of 8.2 % ( 7.5 - 8.9 % ) at 4 mo , 10.6 % ( 9.5 - 11.8 % ) at 8 mo , and 10.5 % ( 8.9 - 12.0 % ) at 12 mo without differences between groups at any time ( P = 0.64 ) . At 12 mo , PRO BMD was higher by 1.6 % ( 0.3 - 3.0 % ) at WB , 2.1 % ( 0.6 - 3.7 % ) at LS , and 1.4 % ( 0.2 - 2.5 % ) at TH compared with  CARB  .  PRO calcium intake was higher ( PRO : 1140 + /- 58 mg/d , CARB : 766 + /- 46 ; P < 0.01 ) , as was urinary calcium ( PRO : 163 + /- 15 mg/d , CARB : 100 + /- 9.2 ; P < 0.01 ) . A reduced-energy diet supplying 1.4 g.kg(-1).d(-1 ) protein and 3 dairy servings increased urinary calcium excretion but provided improved calcium intake and attenuated bone loss over 4 mo of weight loss and 8 additional mo of weight maintenance Dietary protein increases urinary calcium losses and has been associated with higher rates of hip fracture in cross-cultural studies . However , the relation between protein and risk of  osteoporotic bone fractures among individuals has not been examined in detail . In this prospect i ve study , usual dietary intake was measured in 1980 in a cohort of 85,900 women , aged 35 - 59 years , who were participants in the Nurses ' Health Study . A mailed food frequency question naire was used and incident hip ( n = 234 ) and distal forearm ( n = 1,628 ) fractures were identified by self-report during the following 12 years . Information on other factors related to osteoporosis , including obesity , use of postmenopausal estrogen , smoking , and physical activity , was collected on biennial question naires . Dietary measures were up date d in 1984 and 1986 . Protein was associated with an increased risk of forearm fracture ( relative risk ( RR ) = 1.22 , 95 % confidence interval ( Cl ) 1.04 - 1.43 , p for trend = 0.01 ) for women who consumed more than 95 g per day compared with those who consumed less than 68 g per day . A similar increase in risk was observed for animal protein , but no association was found for consumption of vegetable protein . Women who consumed five or more servings of red meat per week also had a significantly increased risk of forearm fracture ( RR = 1.23 , 95 % Cl 1.01 - 1.50 ) compared with women who ate red meat less than once per week . Recall of teenage diet did not reveal any increased risk of forearm fracture for women with higher consumption of animal protein or red meat during this earlier period of life . No association was observed between  adult protein intake  and the incidence of hip fractures , though power to assess this association was low BACKGROUND Controversy exists concerning the effects of higher total protein intake ( TPro ) on bone health , which may be associated with reduced bone mineral density ( BMD ) . However , whey protein ( WP ) may induce bone formation because of its basic component , milk basic protein . OBJECTIVE This study assessed the effects of WP supplementation , TPro , and change in TPro ( postsupplementation - presupplementation ) on BMD and bone mineral content ( BMC ; total body , lumbar spine , total femur , and femoral neck ) in overweight and class I obese middle-aged adults following an exercise intervention . METHODS This analysis used data from a double-blind , r and omized , placebo-controlled 36-wk WP supplementation trial , wherein participants consumed a 1.7-MJ ( 400-kcal ) supplement ( 0 , 20 , 40 , or 60 g WP/d ) along with their otherwise unrestricted diet while participating in a resistance and aerobic exercise intervention ( 3 d/wk ) . TPro was the summation of WP and habitual dietary intakes ( 4-d food record ) . Statistical analyses for WP were based on group and bone data [ n = 186 , 108 women ; mean ± SD age : 49 ± 8 y ; body mass index ( BMI ; in kg/m2 ) : 30.1 ± 2.8 ] , whereas TPro was based on dietary and bone data ( n = 113 , 70 women ; age 50 ± 8 y ; BMI 30.1 ± 2.9 ) . RESULTS WP supplementation , regardless of dose , did not influence BMD or BMC following the intervention . By using a multiple linear regression model , TPro ( expressed as g/d or g · kg-1 · d-1 ) and change in TPro ( expressed as g/d ) were not associated with responses over time in total or regional BMD or BMC . By using a cluster analysis approach [ < 1.0 ( n = 41 ) , 1.0 - 1.2 ( n = 28 ) , and ≥1.2 g · kg-1 · d-1 ( n = 44 ) ] , TPro was also not associated with responses in total or regional BMD or BMC over time . CONCLUSION WP supplementation and total dietary protein intake did not negatively or beneficially influence bone quantity in overweight and obese adults during a 9-mo exercise intervention . This trial was registered at clinical trials.gov as NCT00812409 Objective To examine the effects of food groups and dietary nutrients on  bone loss in elderly Chinese population . Design Prospect i ve cohort study . Setting : A longitudinal study started at 2001 in Hong Kong . Participants 1225 Chinese men and 992 women aged 65 years and over in the community . Methods Daily intake of food groups and dietary nutrients at baseline was assessed by a food frequency question naire . Nutrient intake was adjusted for energy intake by residual method . Linear regression was used to examine the association of BMD change and food group or energy-adjusted nutrient intake with adjustment for demographic , anthropometric , lifestyle factors , and daily energy intake ( for food group only ) . Results Higher fish intake was associated with smaller bone loss in hip ( B=−0.611 , p=0.004 ) and femoral neck ( B=−0.724 , p=0.040 ) in men . None of the food groups were associated with bone loss in both measured sites in women . For men , lower intake of protein ( B=−0.012 , p=0.003 ) , phosphorus ( B=−0.0008 , p=0.001 ) , sodium ( B=−0.0002 , p=0.023 ) and isoflavone ( B=−1.084 , p=0.030 ) was associated with greater BMD loss in hip , whereas lower intake of protein ( B=−0.018 , p=0.006 ) and sodium ( B=−0.0004 , p=0.018 ) was associated with greater BMD loss in femoral neck . However , these significant associations disappeared after further adjustment for energy-adjusted calcium and vitamin D intakes . None of the nutrients were associated with BMD loss in both measured sites in women . Conclusions Greater fish intake may help to reduce bone loss in this sample of elderly Chinese men . The significant association between various nutrients and bone loss  in elderly Chinese men was likely due to the influence of dietary calcium and vitamin D intakes . The role of food groups and dietary nutrients on bone health in this sample of elderly Chinese women seems to be minimal One of the main focuses of lifestyle modification for the prevention of osteoporosis and osteoporotic fractures  in Japan is improvement in dietary calcium intake . However , virtually no r and omized controlled trial to assess the preventive effects of administration of calcium on the risk of fractures has been conducted in Japan . In this study , we review ed all the scientific papers currently available from medical literature data bases to propose evidence -based recommendations on the preventive procedures for osteoporosis . The result of the present systematic review gives the evidence showing that calcium supplementation or optimal dietary calcium intake increases bone density in childhood and adolescence and reduces the risk of fracture due to osteoporosis in the elderly people regardless of the gender . The evidence also supports the current health policy guiding the elderly to increase their dietary calcium intake in daily life Weight reduction induces bone loss by several factors , and the effect of higher protein ( HP ) intake during caloric restriction on bone mineral density ( BMD ) is not known . Previous study design s examining the longer-term effects of HP diets have not controlled for total calcium intake between groups and have not examined the relationship between bone and endocrine changes . In this r and omized , controlled study , we examined how BMD ( areal and volumetric ) , turnover markers , and hormones [ insulin-like growth factor 1 ( IGF-1 ) , IGF-binding protein 3 ( IGFBP-3 ) , 25-hydroxyvitamin D , parathyroid hormone ( PTH ) , and estradiol ] respond to caloric restriction during a 1-year trial using two levels of protein intake . Forty-seven postmenopausal women ( 58.0 ± 4.4 years ; body mass index of 32.1 ± 4.6 kg/m(2 ) ) completed the 1-year weight-loss trial and were on a higher ( HP , 24 % , n = 26 ) or normal protein ( NP , 18 % , n = 21 ) and fat intake ( 28 % ) with controlled calcium intake of 1.2 g/d . After 1 year , subjects lost 7.0 % ± 4.5 % of body weight , and protein intake was 86 and 60 g/d in the HP and NP groups , respectively . HP compared with NP diet attenuated loss of BMD at the ultradistal radius , lumbar spine , and total hip and trabecular volumetric BMD and bone mineral content of the tibia . This is consistent with the higher final values of IGF-1 and IGFBP-3 and lower bone-resorption marker ( deoxypyridinoline ) in the HP group than in the NP group ( p < .05 ) . These data show that a higher  dietary protein during weight reduction increases serum IGF-1 and attenuates total and trabecular bone loss at certain sites in postmenopausal women Abstract It has been hypothesized that high protein intakes are associated with lower bone mineral content ( BMC ) . Previous studies yield conflicting results and thus far no studies have undertaken the interaction of body mass index ( BMI ) and physical activity with protein intakes in relation to BMC and bone mineral density ( BMD ) . Objective To evaluate the associations of dietary total protein ( TP ) , animal protein ( AP ) and plant protein ( PP ) intakes with BMC and BMD and their changes . We tested also the interactions of protein intake with , obesity ( BMI ≤30 vs. > 30 kg/m2 ) and physical activity level ( passive vs. active ) . Design / Setting Prospect i ve cohort study ( Osteoporosis Risk-Factor and Fracture-Prevention Study ) . Participants / measures At the baseline , 554 women aged 65 - 72 years filled out a 3-day food record and a question naire covering data on lifestyle , physical activity , diseases , and medications . Intervention group received calcium 1000 mg/d and cholecalciferol 800 IU for 3 years . Control group received neither supplementation nor placebo . Bone density was measured at baseline and year 3 , using dual energy x-ray absorptiometry . Multivariable regression analyses were conducted to examine the associations between protein intake and BMD and BMC . Results In cross-sectional analyses energy-adjusted TP ( P≤0·029 ) and AP ( P≤0·045 ) but not PP ( g/d ) were negatively associated with femoral neck ( FN ) BMD and BMC . Women with TP≥1·2 g/kg/body weight ( BW ) ( Ptrend≤0·009 ) had lower FN , lumbar spine ( LS ) and total BMD and BMC . In follow-up analysis , TP ( g/kg/BW ) was inversely associated with LS BMD and LS BMC . The detrimental associations were stronger in women with BMI < 30 kg/m2 . In active women , TP ( g/kg/BW ) was positively associated with LS BMD and FN BMC changes . Conclusions This study suggests detrimental associations between protein intake and bone health . However , these negative associations maybe counteracted by BMI > 30 kg/m2 and physical activity Dietary data from a prospect i ve study were used to relate factors influencing calcium balance ( estimates of dietary calcium intake , protein intake from nondairy animal sources ( meat , fish , and eggs ) , and coffee consumption ) to the incidence of  hip fracture . During the years 1977 - 1983 , women and men born between 1925 and 1940 and living in one of three Norwegian counties were invited to a  cardiovascular screening that included a dietary survey . The attendance rate at screening was 91.1 % , and 90.7 % of these persons ( 19,752 women and 20,035 men ) filled in and returned a semiquantitative dietary question naire . This cohort was followed for an average of 11.4 years ( range , 0.01 - 13.8 years ) with respect to hip fracture , defined as cervical or trochanteric fracture . During follow-up , 213 hip fractures were identified , excluding fractures associated with high-energy trauma and metastatic bone disease . There was no clear association between  calcium intake or nondairy animal protein intake  and hip fracture in this cohort . However , an elevated risk of fracture was found in women with a high intake of protein from nondairy animal sources in the presence of low calcium intake ( relative risk = 1.96 ( 95 % confidence interval 1.09 - 3.56 ) for the highest quarter of nondairy protein intake and the lowest quarter of calcium intake vs. the three lower quarters of protein intake and the three higher quarters of calcium intake ) . Women who drank nine or more cups of coffee per day also had an increased risk of fracture , while there was no association between coffee consumption and hip fracture in men . Although these findings do not necessarily imply causal relations , they suggest the presence of risk factors for hip fracture that act through a negative calcium balance in this population Abstract : Quantitative ultrasound ( QUS ) assessment of bone is a strong predictor of hip fractures and is currently an FDA -approved tool to identify women at risk of osteoporosis . However , few studies have investigated the lifestyle and genetic correlates of QUS in women . This study investigated the cross-sectional associates of several lifestyle , demographic and genetic factors with calcaneal QUS parameters ( broadb and ultrasound attenuation ( BUA ) and speed of sound ( SOS ) ) in 393 women aged 45–53 years .  Leisure-time and historical physical activity , dietary calcium and protein , body composition , vitamin D receptor genotypes , menopause status , other health behaviors , calcaneal QUS parameters and bone mineral density ( BMD ) were assessed at a single clinic visit .  Lean mass , recent physical activity and African-American race were the strongest correlates of SOS whereas dietary protein , calcium and recent physical activity were the strongest correlates of BUA . These predictors explained 13 % and 6 % of the variance in SOS and BUA , respectively . Smoking , alcohol intake , education , hormone replacement therapy , calcium and vitamin D supplements , historical physical activity and vitamin D receptor genotypes were not significantly associated with BUA or SOS . Lean body mass and premenopausal status were the strongest correlates of lumbar BMD whereas lean body mass , physical activity , African-American race and body mass index were significantly related to femoral neck BMD . Physical activity remained predictive of SOS after controlling for lumbar BMD . The spectrum and magnitude of risk factors for SOS and BUA , including lean body mass , physical activity , race , protein and calcium intake , parallel previously observed predictors of BMD BACKGROUND It has been hypothesized that hip-fracture rates are higher in developed than in developing countries because high-protein ( HP ) Western diets induce metabolic acidosis and hypercalciuria . Confounders include interactions between dietary protein and calcium , sodium , and potassium . OBJECTIVE We determined whether an HP or a high-normal-protein ( HNP ) weight-loss diet caused greater loss in bone mineral density ( BMD ) over 24 mo . DESIGN The Weight Loss , Protein and Bone Density Study was conducted from 2008 to 2011 in 323 overweight [ body mass index ( BMI ; in kg/m(2 ) ) > 27 ] postmenopausal women , with a total hip BMD t score less than -2.0 . Subjects were r and omly assigned to receive an isocaloric calcium-replete HP ( ≥90 g protein/d ) or HNP ( < 80 g protein/d ) weight-loss diet , with the aim of a difference of 20 g protein/d . A total of 186 subjects ( 90 subjects in the HP group , 96 subjects in the HNP group ) completed 12 mo , and 137 subjects ( 69 subjects in the HP group , 68 subjects in the HNP group ) completed 24 mo . RESULTS Biomarkers confirmed a difference in protein intake of 16 and 13.1 g at 12 and 24 mo , respectively . Mean ( ±SE ) weight loss was equal ; HP subjects lost 7.9 ± 0.9 kg and HNP subjects lost 8.9 ± 0.9 kg at 24 mo . Subjects lost 1 - 2 % BMD annually at lumbar spine vertebrae 2 - 4 , the forearm , the femoral neck , and hip . ANCOVA showed no effect of the HP or HNP diet ( P > 0.05 for diet and diet-time interactions ) . A diet-by-time analysis showed that the HNP diet increased C-terminal telopeptide and osteocalcin ( P ≤ 0.001 for each ) despite hypercalciuria ( P = 0.029 ) . CONCLUSION High dietary protein intake during weight loss has no clinical ly significant effect on bone density but slows bone turnover . This trial was registered at the Australian and New Zeal and Clinical Trials Registry ( http://www.anzctr.org.au ) as ACTRN12608000229370 BACKGROUND Protein and alkalizing minerals are increasingly described as playing a major role in influencing bone status , not only in the elderly but also in children and adolescents . OBJECTIVE We examined whether the long-term dietary protein intake and diet net acid load are associated with bone status in children . DESIGN In a prospect i ve study design in 229 healthy children and adolescents aged 6 - 18 y , long-term dietary intakes were calculated from 3-d weighed dietary records that were collected yearly over the 4-y period before a one-time bone analysis . Dietary acid load was characterized as potential renal acid load ( PRAL ) by using an algorithm including dietary protein , phosphorus , magnesium , and potassium . Proximal forearm bone variables were measured by peripheral quantitative computed tomography . RESULTS After adjustment for age , sex , and energy intake and control for forearm muscularity , BMI , growth velocity , and pubertal development , we observed that long-term  dietary protein intake  was significantly positively associated with periosteal circumference ( P < 0.01 ) , which reflected bone modeling , and with cortical area ( P < 0.001 ) , bone mineral content ( P < 0.01 ) , and polar strength strain index ( P < 0.0001 ) , which reflected a combination of modeling and remodeling . Children with a higher dietary PRAL had significantly less cortical area ( P < 0.05 ) and bone mineral content ( P < 0.01 ) . Long-term calcium intake had no significant effect on any bone variable . CONCLUSIONS Long-term dietary protein intake appears to act anabolically on diaphyseal bone strength during growth , and this may be negated , at least partly , if dietary PRAL is high , ie , if the intake of alkalizing minerals is low Currently there is no consensus on the impact of dietary protein on calcium and bone metabolism . This study was conducted to examine the effect of increasing protein intake on urinary calcium excretion and to compare circulating levels of IGF-I and biochemical markers of bone turnover in healthy older men and women who consumed either a high or a low protein food supplement for 9 wk . Thirty-two subjects with usual protein intakes of less than 0.85 g/kg.d were r and omly assigned to daily high ( 0.75 g/kg ) or low ( 0.04 g/kg ) protein supplement groups . Isocaloric diets were maintained by advising subjects to reduce their intake of carbohydrates . Selected biochemical measurements were made at baseline and on d 35 and either d 49 or 63 . Changes in urinary calcium excretion in the two groups did not differ significantly over the course of the study . The high protein group had significantly higher levels of serum IGF-I ( P = 0.008 ) and lower levels of urinary N-telopeptide ( P = 0.038 ) over the period of d 35 - 49 or 63 . We conclude that increasing protein intake from 0.78 to 1.55 g/kg.d with meat supplements in combination with reducing carbohydrate intake did not alter urine calcium excretion , but was associated with higher circulating levels of IGF-I , a bone growth factor , and lowered levels of urinary N-telopeptide , a marker of bone resorption . In contrast to the widely held belief that increased protein intake results in calcium wasting , meat supplements , when exchanged isocalorically for carbohydrates , may have a favorable impact on the skeleton in healthy older men and women CONTEXT Consolidation and maintenance of peak bone mass in young adulthood may be compromised by inactivity , low dietary calcium , and diet-induced weight loss . OBJECTIVE We aim ed to determine whether higher intakes of dairy foods , dietary calcium , and protein during diet- and exercise-induced weight loss affected markers of bone health . PARTICIPANTS Participants included premenopausal overweight and obese women . DESIGN /INTERVENTION Ninety participants were r and omized into three groups ( n = 30 per group ) : high protein and high dairy ( HPHD ) , adequate protein and medium dairy ( APMD ) , and adequate protein and low dairy ( APLD ) , differing in dietary protein ( 30 , 15 , or 15 % of energy , respectively ) , dairy foods ( 15 , 7.5 , or < 2 % of energy from protein , respectively ) , and dietary calcium ( ∼1600 , ∼1000 , or < 500 mg/d , respectively ) . OUTCOME MEASURES Serum and urine bone turnover biomarkers , serum osteoprotegerin ( OPG ) , receptor activator of nuclear factor-κB lig and ( RANKL ) , PTH , 25-hydroxyvitamin D , leptin , and adiponectin measured at 0 and 16 wk . RESULTS All groups lost equivalent body weight ( P < 0.05 ) . N-telopeptide , C-telopeptide ( CTX ) , urinary deoxypyridinoline , and osteocalcin increased in APLD ( P < 0.01 ) , whereas in HPHD , osteocalcin and procollagen 1 amino-terminal propeptide ( P1NP ) increased ( P < 0.05 ) , and all resorption markers remained unchanged . P1NP to CTX and OPG to RANKL ratios increased in HPHD ( P < 0.005 ) , and P1NP to CTX ratio decreased in APLD ( P < 0.05 ) . PTH decreased in HPHD and APMD vs. APLD ( P < 0.005 ) , and 25-hydroxyvitamin D increased in HPHD ( P < 0.05 ) , remained unchanged in APMD , and decreased in APLD ( P < 0.05 ) . Leptin decreased and adiponectin increased in APMD and HPHD only ( P < 0.001 ) . CONCLUSIONS Hypoenergetic diets higher in dairy foods , dietary calcium , and protein with daily exercise , favorably affected important bone health biomarkers vs. diets with less of these bone-supporting nutrients
In older people with osteoporosis , higher protein intake ( ≥ 0.8-g/kg body weight/day , i.e. , above the current RDA ) is associated with higher BMD , a slower rate of bone loss , and reduced risk of hip fracture , provided that dietary calcium intakes are adequate .
Intervention with dietary protein supplements attenuate age-related BMD decrease and reduce bone turnover marker levels , together with an increase in IGF-I and a decrease in PTH .
There is no evidence that diet-derived acid load is deleterious for bone health .
Thus , insufficient dietary protein intakes may be a more severe problem than protein excess in the elderly .
A summary of systematic review s and meta-analyses addressing the benefits and risks of dietary protein intakes  for  bone health in adults suggests that dietary protein levels even above the current RDA may be beneficial in reducing bone loss and hip fracture risk , provided calcium intakes are adequate .
Several systematic review s and meta-analyses have addressed the benefits and risks of dietary protein intakes for bone health in adults .
Adequate supplies of dietary protein are required for optimal bone growth and maintenance of healthy bone .
Variation in protein intakes within the “ normal ” range accounts for 2–4 % of BMD variance in adults .