title: Dietary factors and the incidence of hip fracture in middle-aged Norwegians. A prospective study. Dietary protein and calcium interact to influence calcium retention: a controlled feeding study. Dietary acid load is associated with lower bone mineral density in men with low intake of dietary calcium. Effects of soy protein isolate on bone mineral density and physical performance indices in postmenopausal women-a 2-year randomized, double-blind, placebo-controlled trial Protein consumption and bone fractures in women. Dietary protein is associated with musculoskeletal health independently of dietary pattern: the Framingham Third Generation Study. Short-term changes in calcium but not protein intake alter the rate of bone resorption in healthy subjects as assessed by urinary pyridinium cross-link excretion. Protein intake and lumbar bone density: the Multi-Ethnic Study of Atherosclerosis (MESA). Calcium intake influences the association of protein intake with rates of bone loss in elderly men and women. Isoflavone-rich soy protein isolate attenuates bone loss in the lumbar spine of perimenopausal women. 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. Long-term protein intake and dietary potential renal acid load are associated with bone modeling and remodeling at the proximal radius in healthy children. Relationships between usual nutrient intake and bone-mineral content of women 35-65 years of age: longitudinal and cross-sectional analysis. Protein intake: effects on bone mineral density and the rate of bone loss in elderly women. Controlled high meat diets do not affect calcium retention or indices of bone status in healthy postmenopausal women. Soy proteins and isoflavones affect bone mineral density in older women: a randomized controlled trial. Correlates of Quantitative Ultrasound in the Women’s Healthy Lifestyle Project
   Soy protein has a greater effect on bone in postmenopausal women not on hormone replacement therapy, as evidenced by reducing bone resorption and urinary calcium excretion. A diet high in meat protein and potential renal acid load increases fractional calcium absorption and urinary calcium excretion without affecting markers of bone resorption or formation in postmenopausal women. A nutritional intervention study with hydrolyzed collagen in pre-pubertal Spanish children: influence on bone modeling biomarkers Effect of high vegetable protein diets on urinary calcium loss in middle-aged men and women Vegetarianism, bone loss, fracture and vitamin D: a longitudinal study in Asian vegans and non-vegans Proteins, dietary acid load, and calcium and risk of postmenopausal fractures in the E3N French women prospective study. Veganism, bone mineral density, and body composition: a study in Buddhist nuns The Effect of a Whey Protein Supplement on Bone Mass in Older Caucasian Adults. Bone Size and Bone Mass in 10-Year-Old Danish Children: Effect of Current Diet
   Calcium, diet and fracture risk: a prospective study of 1898 incident fractures among 34 696 British women and men. Specific Collagen Peptides Improve Bone Mineral Density and Bone Markers in Postmenopausal Women—A Randomized Controlled Study Benefits of oral protein supplementation in elderly patients with fracture of the proximal femur. Risk factors for hip fracture in white men: the NHANES I Epidemiologic Follow-up Study. Does dietary protein reduce hip fracture risk in elders? The Framingham osteoporosis study Effect of Daily Exposure to an Isolated Soy Protein Supplement on Body Composition, Energy and Macronutrient Intake, Bone Formation Markers, and Lipid Profile in Children in Colombia The Relation between Dietary Protein, Calcium and Bone Health in Women: Results from the EPIC-Potsdam Cohort Change in bone mineral density and its determinants in pre- and perimenopausal Chinese women: the Hong Kong perimenopausal women osteoporosis study Potassium bicarbonate attenuates the urinary nitrogen excretion that accompanies an increase in dietary protein and may promote calcium absorption. Dietary protein intake and risk of osteoporotic hip fracture in elderly residents of Utah. The effects of soy protein containing isoflavones on lipids and indices of bone resorption in postmenopausal women Effects of soy protein isolate and moderate exercise on bone turnover and bone mineral density in postmenopausal women Effects of food groups and dietary nutrients on bone loss in elderly Chinese population Effect of dietary protein supplements on calcium excretion in healthy older men and women. The effects of a two-year randomized, controlled trial of whey protein supplementation on bone structure, IGF-1, and urinary calcium excretion in older postmenopausal women. Milk Basic Protein Promotes Bone Formation and Suppresses Bone Resorption in Healthy Adult Men Protein Supplements Increase Serum Insulin-Like Growth Factor-I Levels and Attenuate Proximal Femur Bone Loss in Patients with Recent Hip Fracture A lifecourse study of bone resorption in men ages 49-51years: the Newcastle Thousand Families cohort study. [Comparative study of dietary intake and nutritional status in elderly women with and without hip fracture]. Risk Factors for Hip Fracture in Older Men: The Osteoporotic Fractures in Men Study (MrOS). Milk Basic Protein (MBP) Increases Radial Bone Mineral Density in Healthy Adult Women Association of protein intake with bone mineral density and bone mineral content among elderly women: The OSTPRE fracture prevention study
abstract: 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 BACKGROUND The effect of meat protein on calcium retention at different calcium intakes is unresolved . OBJECTIVE The objective was to test the effect of dietary protein on calcium retention at low and high intakes of calcium . DESIGN In a r and omized controlled feeding study with a 2 x 2 factorial crossover design , healthy postmenopausal women ( n = 27 ) consumed either approximately 675 or approximately 1510 mg Ca/d , with both low and high protein ( providing 10 % and 20 % energy ) for 7 wk each , separated by a 3-wk washout period . After 3 wk , the entire diet was extrinsically labeled with (47)Ca , and isotope retention was monitored by whole-body scintillation counting . Clinical markers of calcium and bone metabolism were measured . RESULTS High compared with low dietary protein significantly increased calcium retention from the low-calcium ( 29.5 % compared with 26.0 % absorbed ) but not the high-calcium diet ( 18 % absorbed ) . For the low-calcium diet , this effect nearly balanced a protein-related 0.5-mmol/d greater urinary calcium excretion . Protein-related calciuretic effects were independent of dietary calcium . Testing at 1 , 2 , 3 , 5 , and 7 wk showed no long-term adaptation in urinary acidity or urinary calcium excretion . High compared with low dietary protein decreased urinary deoxypyridinoline and increased serum insulin-like growth factor I without affecting parathyroid hormone , osteocalcin , bone-specific alkaline phosphatase , or tartrate-resistant acid phosphatase . CONCLUSIONS In healthy postmenopausal women , a moderate increase in dietary protein , from 10 % to 20 % of energy , slightly improved calcium absorption from a low-calcium diet , nearly compensating for a slight increase in urinary calcium excretion . Under practical dietary conditions , increased dietary protein from animal sources was not detrimental to calcium balance or short-term indicators of bone health High dietary acid load ( DAL ) may be detrimental to bone mineral density ( BMD ) . The objectives of the study were to : ( 1 ) evaluate the cross-sectional relation between DAL and BMD ; and ( 2 ) determine whether calcium intake modifies this association . Men ( n = 1218 ) and women ( n = 907 ) aged ≥60 years were included from the National Health and Nutrition Examination Survey 2005 - 2008 .  Nutrient intake from 2 , 24-hour recalls was used to calculate net endogenous acid production ( NEAP ) and potential renal acid load  ( PRAL ) ( mEq/d ) . PRAL was calculated from dietary calcium ( PRALdiet ) and diet + supplemental calcium ( PRALtotal ) . Tests for linear trend in adjusted mean BMD of the hip and lumbar spine were performed across energy-adjusted NEAP and PRAL quartiles . Modification by calcium intake ( dietary or total ) above or below 800 mg/d was assessed by interaction terms . Overall , mean age was 69 ± 0.3 years . Among women , there was no association between NEAP and BMD  . PRALdiet was positively associated with proximal femur BMD ( p trend = 0.04 ) . No associations were observed with PRALtotal at any BMD site ( p range , 0.38 - 0.82 ) . Among men , no significant associations were observed between BMD and NEAP or PRAL . However , an interaction between PRALdiet and calcium intake was observed with proximal femur BMD ( p = 0.08 ) . An inverse association between PRALdiet and proximal femur BMD was detected among men with < 800 mg/d dietary calcium ( p = 0.02 ) ; no associations were found among men with ≥800 mg/d ( p = 0.98 ) . A significant interaction with PRALtotal was not observed . In conclusion , when supplemental calcium is considered , there is no association between DAL and  BMD among adults . Men with low dietary calcium showed an inverse relation with PRAL at the proximal femur ; in women no interaction was observed . This study highlights the importance of calcium intake in counteracting the adverse effect of DAL on bone health . Further research should determine the relation between DAL and change in BMD with very low calcium intake Objective : Postmenopausal decreases in body composition , physical performance , and bone mass have been shown to be reversed by estrogen , but given the concerns regarding its use , women are looking for alternatives such as soy isoflavones . Most studies on the effects of soy on bone mineral density ( BMD ) in postmenopausal women have been short-term , that is , 3 to 6 months , and failed to provide conclusive evidence . There is no evidence of its effects on physical performance . The aim of the present study was to investigate the effects of soy plus isoflavones on BMD and physical performance in postmenopausal women . Methods : This was a 2-year r and omized controlled trial . A total of 203 healthy postmenopausal women were given either 25 g of soy protein without isoflavones , 25 g of soy protein with 90 mg of isoflavones , or 25 g of milk protein ( casein and whey ) as a control agent for 24 months . Women were followed every 6 months with BMD and physical performance measurements for 2 years . Primary analysis was intent-to-treat analysis . Analysis of variance , & khgr;2 and Fisher 's exact tests , and analysis of covariance were used . Results : There was a significant decrease in the BMD of the lumbar spine and femoral neck in those who completed the study in all groups . Soy isoflavones prevented major bone loss from baseline at the femoral trochanter with no between-group significance . Physical performance measurements decreased in all the groups . Conclusions : Twenty-five grams of soy protein with 90 mg of isoflavones has no added benefit in preventing bone loss or improving physical performance 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 : Above-average dietary protein , as a single nutrient , improves musculoskeletal health . Evaluating the link between dietary protein and musculoskeletal health from a whole-diet perspective is important , as dietary guidelines focus on dietary patterns . Objective : We examined the prospect i ve association of novel dietary protein food clusters ( derived from established dietary pattern techniques ) with appendicular lean mass ( ALM ) , quadriceps strength ( QS ) , and bone mineral density ( BMD ) in 2986 men and women , aged 19 - 72 y , from the Framingham Third Generation Study . Design : Total protein intake was estimated by food-frequency question naire in 2002 - 2005 . A cluster analysis was used to classify participants into mutually exclusive groups , which were determined by using the percentage of contribution of food intake to overall protein intake . General linear modeling was used to 1 ) estimate the association between protein intake ( grams per day ) and BMD , ALM , appendicular lean mass normalized for height ( ALM/ht2 ) , and QS ( 2008 - 2011 ) and to 2 ) calculate adjusted least-squares mean outcomes across quartiles of protein ( grams per day ) and protein food clusters . Results : The mean ± SD age of subjects was 40 ± 9 y ; 82 % of participants met the Recommended Daily Allowance ( 0.8 g · kg body weight-1 · d-1 ) . The following 6 dietary protein food clusters were identified : fast food and full-fat dairy , fish , red meat , chicken , low-fat milk , and legumes  . BMD was not different across quartiles of protein intake ( P-trend range = 0.32 - 0.82 ) ; but significant positive trends were observed for ALM , ALM/ht2 ( P < 0.001 ) , and QS ( P = 0.0028 ) . Individuals in the lowest quartile of total protein intake ( quartile 1 ) had significantly lower ALM , ALM/ht2 , and QS than did those in the higher quartiles of intake ( quartiles 2 - 4 ; ( P ranges = 0.0001 - 0.003 , 0.0007 - 0.003 , and 0.009 - 0.05 , respectively ) . However , there were no associations between protein clusters and any musculoskeletal outcome in adjusted models . Conclusions : In a protein-replete cohort of adults , dietary protein is associated with ALM and QS but not with BMD . In this study , dietary protein food patterns do not provide further insight into beneficial protein effects on muscle outcomes This study was conducted to determine whether the markers of bone resorption , pyridinium cross-links of collagen , are sensitive to changes in dietary protein and calcium intake . Fifteen young healthy subjects ( 7 males and 8 females ) participated in three 5-d diet periods . Dietary intake during each dietary period consisted of : 1 ) low nitrogen and low calcium [ 0.49 + /- 0.11 g protein/ ( kg.d ) , 429 + /- 190 mg calcium/d ] ; 2 ) low nitrogen and high calcium [ 0.44 + /- 0.08 g protein/(kg.d ) , 1643 + /- 171 mg calcium/d ] ; and 3 ) a high nitrogen and high calcium [ 2.71 + /- 0.75 g protein/(kg.d ) , 1589 + /- 633 mg calcium/d ] diet , and this was compared with subjects ' baseline dietary intake [ 0.99 + /- 0.51 g protein/(kg.d ) , 589 + /- 152 mg calcium/d ] . The order of these diets was r and omly assigned . Twenty-four-hour and 3-h urine sample s were collected before and during each dietary period and were analyzed for pyridinium cross-links ( pyridinoline , deoxypyridinoline ) , nitrogen and creatinine . The rate of pyrdinium cross-link excretion did not vary with protein intake but was approximately 33 % lower ( P < 0.01 ) during periods of high compared with low calcium intake . These data indicate that a short-term increase in calcium intake is accompanied by a reduced rate of bone resorption and that this effect is independent of dietary protein intake Dietary protein has been shown to increase urinary Ca excretion in r and omised controlled trials , and diets high in protein may have detrimental effects on bone health ; however , studies examining the relationship between dietary protein and bone health have conflicting results . In the present study , we examined the relationship between dietary protein ( total , animal and vegetable protein ) and lumbar spine trabecular volumetric bone mineral density ( vBMD ) among participants enrolled in the Multi-Ethnic Study of Atherosclerosis ( n 1658 ) .  Protein intake was assessed using a FFQ obtained at baseline examination ( 2000 - 2 ) . Lumbar spine vBMD was measured using quantitative computed tomography ( 2002 - 5 ) , on average 3 years later . Multivariable linear and robust regression techniques were used to examine the associations between dietary protein and vBMD . Sex and race/ethnicity jointly modified the association of dietary protein with vBMD ( P for interaction = 0·03 ) . Among white women , higher vegetable protein intake was associated with higher vBMD ( P for trend = 0·03 ) , after adjustment for age , BMI , physical activity , alcohol consumption , current smoking , educational level , hormone therapy use , menopause and additional dietary factors . There were no consistently significant associations for total and animal protein intakes among white women or other sex and racial/ethnic groups . In conclusion , data from the present large , multi-ethnic , population -based study suggest that a higher level of protein intake , when substituted for fat , is not associated with poor bone health . Differences in the relationship between protein source and race/ethnicity of study population s may in part explain the inconsistent findings reported previously 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 No published studies have directly examined the effect of soy protein with isoflavones on bone or bone turnover  in perimenopausal women . OBJECTIVE Our objective was to determine the effects of 24 wk of consumption of soy protein isolate with isoflavones ( 80.4 mg/d ) in attenuating bone loss during the menopausal transition . DESIGN Perimenopausal subjects were r and omly assigned , double blind , to treatment : isoflavone-rich soy ( SPI+ ; n = 24 ) , isoflavone-poor soy ( SPI- ; n = 24 ) , or whey ( control ; n = 21 ) protein . At baseline and posttreatment , lumbar spine bone mineral density ( BMD ) and bone mineral content ( BMC ) were measured by using dual-energy X-ray absorptiometry . At baseline , midtreatment , and posttreatment , urinary N:-telopeptides and serum bone-specific alkaline phosphatase ( BAP ) were measured . RESULTS The percentage change in lumbar spine BMD and BMC , respectively , did not differ from zero in the SPI+ or SPI- groups , but loss occurred in the control group ( -1.28 % , P : = 0.0041 ; -1.73 % , P : = 0.0037 ) . By regression analysis , SPI+ treatment had a positive effect on change in BMD ( 5.6 % ; P : = 0.023 ) and BMC ( 10.1 % ; P : = 0.0032 ) . Baseline BMD and BMC ( P : < or = 0.0001 ) negatively affected the percentage change in their respective models ; baseline body weight ( P : = 0.0036 ) and bone-free lean weight ( P : = 0.016 ) contributed positively to percentage change in BMD and BMC , respectively . Serum BAP posttreatment was negatively related to percentage change in BMD ( P : = 0.0016 ) and BMC ( P : = 0.019 ) . Contrast coding using analyses of covariance with BMD or BMC as the outcome showed that isoflavones , not soy protein , exerted the effect . CONCLUSION Soy isoflavones attenuated bone loss from the lumbar spine in perimenopausal women 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 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 In a 4-yr clinical trial , effect on single-photon absorptiometric measurements of arm bones of usual intakes of energy and 14 nutrients plus vitamin-mineral supplements was studied in 99 women , aged 35 - 65 , r and omly assigned to placebo ( NS ) or calcium-supplemented ( 1.5 g)(S ) groups . Cross-sectional analysis of initial bone measurements showed vitamin C ( r = 0.313 , p less than 0.05 ) and niacin ( r = 0.353 , p less than 0.01 ) correlated with ulna in postmenopausal subjects ( n = 67 ) . Longitudinal analysis of bone-change rates of postmenopausal subjects ( NS + S ) showed higher  calcium  intakes associated with lower loss rates of humerus bone-mineral content ( BMC ) ( r = 0.360 , p less than 0.01 ) . In postmenopausal NS but not S subjects , energy , protein , calcium , phosphorus , zinc , and folate correlate significantly with change in radius BMC ; high levels of intake correlated with slower loss ( p less than 0.05 ) . Several nutrients besides calcium are related to bone loss in women 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 Calcium balance is decreased by an increased intake of purified proteins , although the effects of common dietary sources of protein ( like meat ) on calcium economy remain controversial . We compared the effects of several weeks of controlled high and low meat diets on body calcium retention , using sensitive radiotracer and whole body scintillation counting methodology . Healthy postmenopausal women ( n = 15 ) consumed diets with similar calcium content ( approximately 600 mg ) , but either low or high in meat ( 12 vs. 20 % of energy as protein ) for 8 wk each , in a r and omized crossover design . After 4 wk of equilibration of each diet , calcium retention was measured by extrinsically labeling the 2-d menu with (47)Ca , followed by whole body scintillation counting for 28 d. Urinary and blood indicators of bone metabolism were also determined for each diet . Calcium retention was not different during the high and low meat dietary periods ( d 28 , mean + /- pooled SD : 17.1 and 15.6 % , + /-0.6 % , respectively ; P = 0.09 ) . An initially higher renal acid excretion in subjects consuming the high meat compared with the low meat diet decreased significantly with time . The diets did not affect urinary calcium loss or indicators of bone metabolism . In conclusion , under controlled conditions , a high meat compared with a low meat diet for 8 wk did not affect calcium retention or biomarkers of bone metabolism in healthy postmenopausal women .  Calcium retention is not reduced when subjects consume a high protein diet from common dietary sources such as meat BACKGROUND Soy foods contain several components ( isoflavones and amino acids ) that potentially affect bone . Few long-term , large clinical trials of soy as a means of improving bone mineral density ( BMD ) in late postmenopausal women have been conducted . OBJECTIVE Our goal was to evaluate the long-term effect of dietary soy protein and /or soy isoflavone consumption on skeletal health in late postmenopausal women . DESIGN We conducted a r and omized , double-blind , placebo-controlled clinical trial in 131 healthy ambulatory women aged > 60 y. Ninety-seven women completed the trial . After a 1-mo baseline period , subjects were r and omly assigned into 1 of 4 intervention groups : soy protein ( 18 g ) + isoflavone tablets ( 105 mg isoflavone aglycone equivalents ) , soy protein + placebo tablets , control protein + isoflavone tablets , and control protein + placebo tablets . RESULTS Consumption of protein powder and isoflavone pills did not differ between groups , and compliance with the study powder and pills was 80 - 90 % . No significant differences in BMD were observed between groups from baseline to 1 y after the intervention or in BMD change between equol and non-equol producers . However , there were significant negative correlations between total dietary protein ( per kg ) and markers of bone turnover ( P < 0.05 ) . CONCLUSIONS Because soy protein and isoflavones ( either alone or together ) did not affect BMD , they should not be considered as effective interventions for preserving skeletal health in older women . The negative correlation between dietary protein and bone turnover suggests that increasing protein intakes may suppress skeletal turnover . This trial was registered at Clinical Trials.gov as NCT00668447 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 Recent reports suggest that soy protein may reduce the risk of osteoporosis in peri- and postmenopausal women . The objective of this study was to examine whether soy supplementation exerts beneficial effects on serum and urinary biomarkers of bone metabolism in postmenopausal women , regardless of whether or not they are on hormone replacement therapy ( HRT ) . A total of 71 women were r and omly assigned to either soy protein ( SP ) or milk-based protein ( MBP ) , 40 g daily for 3 months , in a double-blind parallel design . Forty-two women completed the study ( 20 on SP and 22 on MBP ) . Overall , both protein supplements positively influenced serum IGF-I , known to correlate with bone formation . However , SP had a more pronounced effect on IGF-I than MBP . Urinary deoxypyridinoline ( Dpd ) excretion , a specific biomarker of bone resorption , was significantly reduced by SP , but not by MBP when all women were included . Furthermore , women on MBP experienced a 33 % increase in urinary calcium excretion , whereas SP did not have such an effect . To evaluate whether SP affects women differently on the basis of their HRT status , data from women on HRT ( n = 22 ) and those not on HRT ( n = 20 ) were analyzed separately . The sub analysis of the data indicated that SP had the greatest impact on serum IGF-I ( an increase of 97 % ) in the women not on HRT . The changes in urinary Dpd due to SP were only observed in women not on HRT , indicating that the overall decrease in Dpd occurred with SP in the absence of HRT . These results indicate that soy protein may positively influence bone and calcium homeostasis in postmenopausal women , particularly those not on HRT Our objective in this study was to determine the effects of a high-protein and high-potential renal acid load ( PRAL ) diet on calcium ( Ca ) absorption and retention and markers of bone metabolism . In a r and omized crossover design , 16 postmenopausal women consumed 2 diets : 1 with low protein and low PRAL ( LPLP ; total protein : 61 g/d ; PRAL : -48 mEq/d ) and 1 with high protein and high PRAL ( HPHP ; total protein : 118 g/d ; PRAL : 33 mEq/d ) for 7 wk each separated by a 1-wk break . Ca absorption was measured by whole body scintillation counting of radio-labeled (47)Ca . Compared with the LPLP diet , the HPHP diet increased participants ' serum IGF-I concentrations ( P < 0.0001 ) , decreased serum intact PTH concentrations ( P < 0.001 ) , and increased fractional (47)Ca absorption ( mean ± pooled SD : 22.3 vs. 26.5 ± 5.4 % ; P < 0.05 ) and urinary Ca excretion ( 156 vs. 203 ± 63 mg/d ; P = 0.005 ) . The net difference between the amount of Ca absorbed and excreted in urine did not differ between 2 diet periods ( 55 vs. 28 ± 51 mg/d ) . The dietary treatments did not affect other markers of bone metabolism . In summary , a diet high in protein and PRAL  increases the fractional absorption of dietary Ca , which partially compensates for increased urinary Ca , in postmenopausal women . The increased IGF-I and decreased PTH concentrations in serum , with no change in biomarkers of bone resorption or formation , indicate a high-protein diet has no adverse effects on bone health Abstract Aim : The aim of the study was to investigate the influence of dietary intake of commercial hydrolyzed collagen ( Gelatine Royal ® ) on bone remodeling in pre-pubertal children . Methods : A r and omized double-blind study was carried out in 60 children ( 9.42±1.31 years ) divided into three groups according to the amount of partially hydrolyzed collagen taken daily for 4 months : placebo ( G-I , n=18 ) , collagen ( G-II , n=20 ) and collagen+calcium ( G-III , n=22 ) groups . Analyses of the following biochemical markers were carried out : total and bone alkaline phosphatase ( tALP and bALP ) , osteocalcin , tartrate-resistant acid phosphatase ( TRAP ) , type I collagen carboxy-terminal telopeptide , lipids , calcium , 25-hydroxyvitamin D , insulin-like growth factor-1 ( IGF-1 ) , thyroid-stimulating hormone , free thyroxin and intact parathormone . Results : There was a significantly greater increase in serum IGF-1 in G-III than in G-II ( p<0.01 ) or G-I ( p<0.05 ) during the study period , and a significantly greater increase in plasma tALP in G-III than in G-I ( p<0.05 ) . Serum bALP behavior significantly ( p<0.05 ) differed between G-II ( increase ) and G-I ( decrease ) . Plasma TRAP behavior significantly differed between G-II and G-I ( p<0.01 ) and between G-III and G-II ( p<0.05 ) . Conclusion : Daily dietary intake of hydrolyzed collagen seems to have a potential role in enhancing bone remodeling at key stages of growth and development Objective : To determine the effect of high-protein diets , which have recently been promoted for their health benefits , on urinary calcium losses and bone turnover in older subjects . Design : R and omized controlled cross-over study . Setting : Teaching hospital and university . Subjects : Twenty hyperlipidemic men and postmenopausal women ( age 56±2 y ) completed the study . Interventions : One-month test and control phases during which subjects consumed equi-energy metabolic diets high in calcium ( 1578 and 1593 mg/day , respectively ) . On the test diet 11 % of total dietary energy from starch in the control bread was replaced by protein ( wheat gluten ) , result ing in 27 % of energy from protein on the test diet vs 16 % on the control diet . Main outcome measure : Urinary calcium excretion . Results : Compared with the control diet , at week 4 , the test diet increased mean ( ±s.e.m . ) 24 h urinary output of calcium ( 139±15 vs 227±21 mg , P=0.004 ) . The treatment difference in urinary calcium loss correlated with the serum anion gap as a marker of metabolic acid production ( r=0.57 , P=0.011 ) . Serum calcium levels were marginally lower 2.41±0.02 vs 2.38±0.02 mmol/l ( P=0.075 ) , but there was no significant treatment difference in calcium balance , possibly related to the high background calcium intake on both diets . Conclusions : In the presence of high dietary calcium intakes the vegetable protein gluten does not appear to have a negative effect on calcium balance despite increased urinary calcium loss . Sponsorship : The University-Industry Research Partnership Program of the Natural Sciences and Engineering Research Council of Canada , Loblaw Br and s Limited , Toronto , ON , and Kraft Canada Inc. Don Mills , ON . DJAJ is funded as a Canada Research Chair in Metabolism and Nutrition at the University of Toronto by the Federal Government of Canada , Ottawa Background / Objectives : The effect of vegan diet on bone loss has not been studied . The aim of this study was to examine the association between veganism and bone loss in postmenopausal women . Subjects/ Methods : The study was design ed as a prospect i ve longitudinal investigation with 210 women , including 105 vegans and 105 omnivores . Femoral neck ( FN ) bone mineral density ( BMD ) was measured in 2008 and 2010 by dual-energy X-ray absorptiometry ( Hologic QDR4500 ) . The incidence of vertebral fracture was ascertained by X-ray report . Serum levels of C-terminal telopeptide of type I collagen ( βCTX ) and N-terminal propeptide of type I procollagen ( PINP ) were measured by Roche Elecsys assays . Serum concentration of 25-hydroxyvitamin D and parathyroid hormone were measured by electrochemiluminescence . Results : Among the 210 women who initially participated in the study in 2008 , 181 women had completed the study and 29 women were lost to follow-up . The rate of loss in FN BMD was −1.91±3.45%/year in omnivores and −0.86±3.81%/year ( P=0.08 ) in vegans . Lower body weight , higher intakes of animal protein and lipid , and corticosteroid use were associated with greater rate of bone loss . The 2-year incidence of fracture was 5.7 % ( n=5/88 ) in vegans , which was not significantly different from omnivores ( 5.4 % , n=6/93 ) . There were no significant differences in βCTX and PINP between vegans and omnivores . The prevalence of vitamin D insufficiency in vegans was higher than in omnivores ( 73 % versus 46 % ; P=0.0003 ) . Conclusions : Vegan diet did not have adverse effect on bone loss and fracture . Corticosteroid use and high intakes of animal protein and animal lipid were negatively associated with bone loss Excess dietary proteins and " acid ash " diets have been suspected to increase the risk of osteoporosis , but experimental and epidemiological evidence is mixed . We aim ed to determine whether the association between protein intake and the overall acid-base equilibrium of the diet ( as renal net acid excretion [ RNAE ] estimate ) and fracture risk vary according to calcium intake . During an average of 8.37 + /- 1.73 yr of follow-up , 2408 women reported a fracture ( excluding high-impact trauma ) among 36,217 postmenopausal women from the E3N prospect i ve study . We used Cox regression models to study the interaction between calcium and , respectively , proteins and RNAE , from the 1993 dietary question naire for fracture risk determination , adjusting for potential confounders . There was no overall association between fracture risk and total protein or RNAE . However , in the lowest quartile of calcium ( < 400 mg/1000 kcal ) , high protein intake was associated with a significant increased fracture risk ( RR = 1.51 for highest versus lowest quartile ; 95 % CI , 1.17 - 1.94 ) . An increasing fracture risk with increasing animal protein intake was also observed ( trend , p < 0.0001 ) . A similar pattern of interaction for fracture risk was observed between RNAE and calcium . In this Western population of postmenopausal women with normal to high protein intake and fairly high calcium intake , there was no overall association between total protein or RNAE and fracture risk . However , there was some evidence that high protein-high acid ash diets were associated with an increased risk of fracture when calcium intake was low ( < 400 mg/1000 kcal ) Summary This cross-sectional study showed that , although vegans had lower dietary calcium and protein intakes than omnivores , veganism did not have adverse effect on bone mineral density and did not alter body composition . Introduction Whether a lifelong vegetarian diet has any negative effect on bone health is a contentious issue . We undertook this study to examine the association between lifelong vegetarian diet and bone mineral density and body composition in a group of postmenopausal women . Methods One hundred and five Mahayana Buddhist nuns and 105 omnivorous women ( average age = 62 , range = 50–85 ) were r and omly sample d from monasteries in Ho Chi Minh City and invited to participate in the study . By religious rule , the nuns do not eat meat or seafood ( i.e. , vegans ) . Bone mineral density ( BMD ) at the lumbar spine ( LS ) , femoral neck ( FN ) , and whole body ( WB ) was measured by DXA ( Hologic QDR 4500 ) . Lean mass , fat mass , and percent fat mass were also obtained from the DXA whole body scan . Dietary calcium and protein intakes were estimated from a vali date d food frequency question naire . Results There was no significant difference between vegans and omnivores in LSBMD ( 0.74 ± 0.14 vs. 0.77 ± 0.14 g/cm2 ; mean ± SD ; P = 0.18 ) , FNBMD ( 0.62 ± 0.11 vs. 0.63 ± 0.11 g/cm2 ; P = 0.35 ) , WBBMD ( 0.88 ± 0.11 vs. 0.90 ± 0.12 g/cm2 ; P = 0.31 ) , lean mass ( 32 ± 5 vs. 33 ± 4 kg ; P = 0.47 ) , and fat mass ( 19 ± 5 vs. 19 ± 5 kg ; P = 0.77 ) either before or after adjusting for age . The prevalence of osteoporosis ( T scores ≤ −2.5 ) at the femoral neck in vegans and omnivores was 17.1 % and 14.3 % ( P = 0.57 ) , respectively . The median intake of dietary calcium was lower in vegans compared to omnivores ( 330 ± 205 vs. 682 ± 417 mg/day , P < 0.001 ) ; however , there was no significant correlation between dietary calcium and BMD . Further analysis suggested that whole body BMD , but not lumbar spine or femoral neck BMD , was positively correlated with the ratio of animal protein to vegetable protein . Conclusion These results suggest that , although vegans have much lower intakes of dietary calcium and protein than omnivores , veganism does not have adverse effect on bone mineral density and does not alter body composition CONTEXT It has been assumed that the increase in urine calcium ( Ca ) that accompanies an increase in dietary protein was due to increased bone resorption . However , studies using stable Ca isotopes have found that dietary protein increases Ca absorption without increasing bone resorption . OBJECTIVE The objective of the study was to investigate the impact of a moderately high protein diet on bone mineral density ( BMD ) . DESIGN This was a r and omized , double-blind , placebo-controlled trial of protein supplementation daily for 18 months . SETTING The study was conducted at two institutional research centers . PARTICIPANTS Two hundred eight older women and men with a body mass index between 19 and 32 kg/m(2 ) and a self-reported protein intake between 0.6 and 1.0 g/kg participated in the study . INTERVENTION Subjects were asked to incorporate either a 45-g whey protein or isocaloric maltodextrin supplement into their usual diet for 18 months . MAIN OUTCOME MEASURE BMD by dual-energy x-ray absorptiometry , body composition , and markers of skeletal and mineral metabolism were measured at baseline and at 9 and 18 months . RESULTS There were no significant differences between groups for changes in L-spine BMD ( primary outcome ) or the other skeletal sites of interest . Truncal lean mass was significantly higher in the protein group at 18 months ( P = .048 ) . C-terminal telopeptide ( P = .0414 ) , IGF-1 ( P = .0054 ) , and urinary urea ( P < .001 ) were also higher in the protein group at the end of the study period . There was no difference in estimated glomerular filtration rate at 18 months . CONCLUSION Our data suggest that protein supplementation above the recommended dietary allowance ( 0.8 g/kg ) may preserve fat-free mass without adversely affecting skeletal health or renal function in healthy older adults Abstract : Lifestyle factors , such as diet , are believed to be involved in modifying bone health , although the results remain controversial , particularly in children and adolescents . The objective of the study was to identify associations between dietary factors and whole body bone measurements in 10-year-old children . The study was a cross-sectional analysis of a r and om sample of 105 healthy Danish children , aged 10 years ( 9.97 ± 0.09 ) . Whole body bone mineral content ( BMC ) and bone area ( BA ) were determined by dual-energy X-ray absorptiometry . The influence of diet ( 7 day food records ) on BMC and BA were examined in bi- and multivariate analyses . The mean intakes of calcium , protein , phosphorus and sodium were 1226 mg , 78 g , 1523 mg and 3.3 g , respectively . In bivariate analyses , BMC and BA were strongly positively correlated with height ( p<0.001 ) and weight ( p<0.001 ) , and with intakes of energy ( p<0.005 ) and several nutrients . BMC was adjusted for size by including BA , height and weight in the multiple linear regression , and BA was adjusted for size by including height and weight in the multiple linear regression . In multivariate analyses , size-adjusted BMC was positively associated with calcium intake ( p = 0.02 ) . Size-adjusted BA was positively associated with dietary protein ( p = 0.003 ) , and negatively associated with intakes of sodium ( p = 0.048 ) and phosphorus ( p = 0.01 ) . In conclusion , calcium intake was positively associated with bone mineralization . There was a positive association between protein and BA , while for phosphorus and sodium the association was negative . The findings suggest that in addition to calcium , the intake of other nutrients influences bone development in prepubertal children OBJECTIVE The risk factors for fractures are incompletely understood . An outst and ing question concerns the optimal amount of dietary calcium needed to minimise the risk of fracture . DESIGN We examined the associations of dietary calcium and other nutrients with self-reported fracture risk in a prospect i ve cohort study . Nutrient intakes were estimated using a semi-quantitative food-frequency question naire administered at recruitment . SETTING The UK . PARTICIPANTS A total of 26 749 women and 7947 men aged 20 - 89 years . RESULTS Over an average of 5.2 years of follow-up , 1555 women and 343 men reported one or more fractures , 72 % of these result ing from a fall . Among women , fracture risk was higher at lower calcium intakes , with a relative risk of 1.75 ( 95 % confidence interval ( CI ) 1.33 - 2.29 ) among women with a calcium intake of < 525 mg day- 1 compared with women with a calcium intake of at least 1200 mg day- 1 ( test for linear trend , P < 0.001 ) . The association of  dietary calcium with fracture risk was stronger among women aged under 50 years at recruitment than among women aged 50 and above .  Dietary calcium intake was not associated with fracture risk in men . Fracture risk was not related to the dietary intake of any other nutrient examined . CONCLUSION In this population , women with a low dietary calcium intake had an increased risk of bone fracture , and this association was more marked among younger women than among older women Introduction : Investigations in rodents as well as in vitro experiments have suggested an anabolic influence of specific collagen peptides ( SCP ) on bone formation and bone mineral density ( BMD ) . The goal of the study was to investigate the effect of 12-month daily oral administration of 5 g SCP vs. placebo ( CG : control group ) on BMD in postmenopausal women with primary , age-related reduction in BMD . Methods : 131 women were enrolled in this r and omized , placebo-controlled double-blinded investigation . The primary endpoint was the change in BMD of the femoral neck and the spine after 12 months . In addition , plasma levels of bone markers — amino-terminal propeptide of type I collagen ( P1NP ) and C-telopeptide of type I collagen ( CTX 1)—were analysed . Results : A total of 102 women completed the study , but all subjects were included in the intention-to-treat ( ITT ) analysis ( age 64.3 ± 7.2 years ; Body Mass Index , BMI 23.6 ± 3.6 kg/m2 ; T-score spine −2.4 ± 0.6 ; T-score femoral neck −1.4 ± 0.5 ) . In the SCP group ( n = 66 ) , BMD of the spine and of the femoral neck increased significantly compared to the control group ( n = 65 ) ( T-score spine : SCP + 0.1 ± 0.26 ; CG −0.03 ± 0.18 ; ANCOVA p = 0.030 ; T-score femoral neck : SCP + 0.09 ± 0.24 ; CG −0.01 ± 0.19 ; ANCOVA p = 0.003 ) . P1NP increased significantly in the SCP group ( p = 0.007 ) , whereas CTX 1 increased significantly in the control group ( p = 0.011 ) . Conclusions : These data demonstrate that the intake of SCP increased BMD  in postmenopausal women with primary , age-related reduction of BMD . In addition , SCP supplementation was associated with a favorable shift in bone markers , indicating increased bone formation and reduced bone degradation Malnutrition has been often suggested as contributing to both the high incidence of hip fracture in elderly people and its complications . In a recent prospect i ve controlled r and omized study , the clinical outcome of elderly patients with osteoporotic fracture of the proximal femur ( hip fracture ) improved by giving a simple oral dietary supplement . This study , however , did not prove that protein was responsible for the clinical improvement since the supplement also contained vitamins and minerals . We addressed this question by comparing the clinical outcome and bone mineral density ( BMD ) changes in elderly patients with hip fracture , receiving two different dietary supplements with different protein contents . Sixty-two patients ( mean age 82 ) admitted into the orthopedic ward for fracture of the proximal femur were r and omized into two groups . One group ( n = 33 ) received 250 ml/day of an oral nutritional supplement containing protein ( 20.4 g ) , mineral salts ( Ca : 0.525 g ) and vitamins A = 750 IU ; D3 = 25 IU ) for a mean of 38 days . A control group ( n = 29 ) received the same supplement dose , but with no protein , for the same period of time . The clinical course was significantly better in the group receiving protein , with 79 % having a favorable course as compared to 36 % ( p less than 0.02 ) in the control group during the stay in the recovery hospital . The rate of complications and deaths was also significantly lower in the protein-supplemented vs the control group ( 52 vs 80 % , p less than 0.05 ) 7 months after hip fracture . The median hospital stay was significantly lower in the protein-supplemented group ( 69 vs 102 days , p less than 0.05 ) . ( ABSTRACT TRUNCATED AT 250 WORDS This prospect i ve population -based study assessed predictors of hip fracture risk in white men . Participants were members of the Epidemiologic Follow-up Study cohort of the First National Health and Nutrition Examination Survey , a nationally representative sample of noninstitutionalized civilians who were followed for a maximum of 22 years . A cohort of 2879 white men ( 2249 in the nutrition and weight-loss sub sample , 1437 in the bone density sub sample ) aged 45 - 74 years at baseline ( 1971 - 1975 ) were observed through 1992 . Ninety-four percent of the original cohort were successfully traced . Hospital records and death certificates were used to identify a total of 71 hip fracture cases ( 61 in the nutrition and weight-loss sub sample , 26 in the bone-density sub sample ) . Among the factors evaluated were age at baseline , previous fractures other than hip , body mass index , smoking status , alcohol consumption , nonrecreational physical activity , weight loss from maximum , calcium intake , number of calories , protein consumption , chronic disease prevalence , and phalangeal bone density . The risk adjusted relative risk ( RR ) of hip fracture was significantly associated with presence of one or more chronic conditions ( RR = 1.91 , 95 % confidence interval [ CI ] = 1.19 - 3.06 ) , weight loss from maximum > or = 10 % ( RR = 2.27 , 95 % CI 1.13 - 4.59 ) , and 1 SD change in phalangeal bone density ( RR = 1.73 , 95 % CI 1.11 - 2.68 ) . No other variables were significantly related to hip fracture risk . Although based on a small number of cases , this is one of the first prospect i ve studies to relate weight loss and bone density to hip fracture risk in men Summary Association between dietary protein and fracture risk is unclear . We examined association between energy-adjusted protein intake  and  hip fracture risk in elders . The risk of hip fracture was reduced in upper quartiles of protein intake when compared with lowest quartile . Introduction Studies of the association between dietary protein intake and hip fracture risk are conflicting . Therefore , we examined protein intake and hip fracture risk in a population -based group of elderly men and women . Methods Five hundred seventy-six women and 370 men from the Framingham Osteoporosis Study with no previous history of hip fracture completed Food Frequency Question naires .  Energy-adjusted protein intake  was evaluated as a continuous variable and as quartiles . Incidence rates and hazard ratios were calculated , adjusting for age , BMI , sex , and energy intake . Results Among 946 participants ( mean age 75 years ) , mean protein intake  was found to be 68 gm/d . Increased protein intake was associated with a decreased risk of hip fracture compared to those in the lowest quartile of protein intake ( Q2 HR = 0.70 , Q3 HR = 0.56 , and Q4 HR = 0.63 ; all p values ≥ 0.044 ) , p for trend was 0.07 . When a threshold effect was considered ( Q2–4 vs Q1 ) , intakes in the higher quartiles combined were associated with a significantly lower risk for hip fracture ( HR = 0.63 ; p = 0.04 ) . Conclusion Our results are consistent with reduced risk of hip fracture with higher dietary protein intake . Larger prospect i ve studies are needed to confirm and extend this finding in elderly men and women ABSTRACT A soy protein – based supplement may optimize bone health , support physical growth , and stimulate bone formation . This study aim ed to assess the effect of a daily soy protein supplement ( SPS ) on nutritional status , bone formation markers , lipid profile , and daily energy and macronutrient intake in children . One hundred seven participants ( 62 girls ) , ages 2 to 9 , started the study and were r and omly assigned to lunch fruit juice with ( n = 57 , intervention group ) or without ( n = 50 , control group ) addition of 45 g ( 230 Kcal ) of a commercial SPS during 12 months ; 84 children ( 51 girls , 33 boys ) completed the study ( 45 and 39 intervention and control , respectively ) . Nutritional assessment included anthropometry and nutrient intakes ; initial and final blood sample s were taken ; insulin-like growth factor-I ( IGF-I ) , osteocalcin , bone specific alkaline phosphatase ( BAP ) , insulin-like growth factor binding protein-3 ( IGFBP-3 ) , cholesterol , triglycerides , low-density lipoprotein ( LDL ) , and high-density lipoprotein ( HDL ) were analyzed . Statistically significant changes ( p < .05 ) in body mass index and weight for age Z scores were observed between groups while changes in body composition were not . Changes in energy , total protein , and carbohydrate intakes were significantly higher in the intervention group ( p < .01 ) . Calorie intake changes were statistically significant between groups ( p < .001 ) , and BAP decreased in both groups , with values within normal ranges . Osteocalcin , IGFBP-3 , and lipid profile were not different between groups . IGF-I levels and IGF/IGFBP-3 ratio increased significantly in both groups . In conclusion , changes in macronutrient and energy intake and nutritional status in the intervention group compared to control group may ensure harmonious and adequate bone health and 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 Summary This 30-month study investigating bone change and its determinants in 438 perimenopausal Chinese women revealed that the fastest bone loss occurred in women undergoing menopausal transition but maintenance of body weight and physical fitness were beneficial for bone health . Soy protein intake also seemed to exert a protective effect . Introduction This 30-month follow-up study aims to investigate change in bone mineral density and its determinants in Hong Kong Chinese perimenopausal women . Methods Four hundred and thirty-eight women aged 45 to 55 years were recruited through r and om telephone dialing and primary care clinic .  Bone mass , body composition , lifestyle measurements were obtained at baseline and at 9- , 18- and 30-month follow-ups . Univariate and stepwise multiple regression analyses were performed with the regression coefficients of BMD/C ( derived from baseline and follow-up measurements ) as the outcome variables . Menopausal status was classified as pre- or postmenopausal or transitional . Results Menopausal status was the strongest determinant of bone changes . An annual bone loss of about 0.5 % was observed among premenopausal , 2 % to 2.5 % among transitional , and about 1.5 % in postmenopausal women . Multiple regression analyses , revealed that a positive regression slope of body weight was protective for follow-up bone loss at all sites . Number of pregnancy , soy protein intake  and walking were protective for total body BMC . Higher baseline LM was also protective for neck of femur BMD . Conclusion Maintenance of body weight and physical fitness were observed to have a protective effect on for bone loss in Chinese perimenopausal women CONTEXT Protein is an essential component of muscle and bone . However , the acidic byproducts of protein metabolism may have a negative impact on the musculoskeletal system , particularly in older individuals with declining renal function . OBJECTIVE We sought to determine whether adding an alkaline salt , potassium bicarbonate ( KHCO3 ) , allows protein to have a more favorable net impact on intermediary indices of muscle and bone conservation than it does in the usual acidic environment . DESIGN We conducted a 41-d r and omized , placebo-controlled , double-blind study of KHCO3 or placebo with a 16-d phase-in and two successive 10-d metabolic diets containing low ( 0.5 g/kg ) or high ( 1.5 g/kg ) protein in r and om order with a 5-d washout between diets . SETTING The study was conducted in a metabolic research unit . PARTICIPANTS Nineteen healthy subjects ages 54 - 82 yr participated . INTERVENTION KHCO3 ( up to 90 mmol/d ) or placebo was administered for 41 d. MAIN OUTCOME MEASURES We measured 24-h urinary nitrogen excretion , IGF-I , 24-h urinary calcium excretion , and fractional calcium absorption . RESULTS KHCO3 reduced the rise in urinary nitrogen excretion that accompanied an increase in protein intake ( P = 0.015 ) and was associated with higher IGF-I levels on the low-protein diet ( P = 0.027 ) with a similar trend on the high-protein diet ( P = 0.050 ) . KHCO3 was also associated with higher fractional calcium absorption on the low-protein diet ( P = 0.041 ) with a similar trend on the high-protein diet ( P = 0.064 ) . CONCLUSIONS In older adults , KHCO3 attenuates the protein-induced rise in urinary nitrogen excretion , and this may be mediated by IGF-I. KHCO3 may also promote calcium absorption independent of the dietary protein content 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 objective To assess the effect of a dietary soy protein supplement containing isoflavones on lipids and indices of bone resorption in postmenopausal women Objective : The aim of this study was to assess the independent and additive effects of soy protein isolate ( SPI ) and moderate-intensity exercise ( EX ) on bone turnover and bone mineral density ( BMD ) . Design : This study used a placebo-controlled , double-blind ( soy ) , r and omized 2 ( SPI vs milk protein isolate [ MPI ] ) × 2 ( EX vs no EX ) design . Sixty-one postmenopausal women were r and omized , and 43 ( 62 ± 5 y ) completed the 9-month intervention ( SPI , n = 10 ; MPI , n = 12 ; SPI + EX , n = 11 ; MPI + EX , n = 10 ) . Serum C-terminal cross-linked telopeptides of type I collagen and serum bone-specific alkaline phosphatase were measured as markers of bone resorption and formation , respectively . BMD was measured by dual-energy x-ray absorptiometry . Results : At 9 months , SPI reduced serum C-terminal cross-linked telopeptides ( −13.3 % ± 15.3 % vs −1.5 % ± 21.0 % ; P = 0.02 ) and serum bone-specific alkaline phosphatase ( −4.7 % ± 14.7 % vs 6.5 % ± 17.7 % ; P = 0.02 ) compared to milk protein isolate . EX attenuated the reduction in serum C-terminal cross-linked telopeptides ( −1.9 % ± 21.6 % vs −12.4 % ± 15.3 % ; P = 0.04 ) ; however , no EX effects were apparent in serum bone-specific alkaline phosphatase at 9 months ( 2.8 % ± 16.1 % vs −1.0 % ± 18.3 % ; P = 0.28 ) . Neither SPI nor EX affected BMD at any site ; however , change in BMD was related to change in fat mass ( r = 0.40 , P < 0.05 ) . Conclusions : In postmenopausal women ( 1 ) SPI reduces bone turnover with no impact on BMD over 9 months ; ( 2 ) moderate-intensity endurance exercise training did not favorably alter bone turnover and had no impact on BMD ; and ( 3 ) there were no additive effects of soy and exercise on bone turnover or BMD 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 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 The effects of dietary protein on bone structure and metabolism have been controversial , with evidence for and against beneficial effects . Because no long-term r and omized , controlled studies have been performed , a two-year study of protein supplementation in 219 healthy ambulant women aged 70 to 80 years was undertaken . Participants were r and omized to either a high-protein drink containing 30 g of whey protein ( n = 109 ) or a placebo drink identical in energy content , appearance , and taste containing 2.1 g of protein ( n = 110 ) . Both drinks provided 600 mg of calcium . Dual-energy X-ray absorptiometric ( DXA ) hip areal bone mineral density ( aBMD ) , 24-hour urinary calcium excretion , and serum insulin-like growth factor 1 ( IGF-1 ) were measured at baseline and at 1 and 2 years . Quantitative computed tomographic ( QCT ) hip volumetric bone mineral density ( vBMD ) and a femoral neck engineering strength analysis were undertaken at baseline and at 2 years . Baseline average protein intake was 1.1 g/kg of body weight per day . There was a significant decrease in hip DXA aBMD and QCT vBMD over 2 years with no between-group differences . Femoral neck strength was unchanged in either group over time . The 24-hour urinary calcium excretion increased significantly from baseline in both groups at 1 year but returned to baseline in the placebo group at 2 years , at which time the protein group had a marginally higher value . Compared with the placebo group , the protein group had significantly higher serum IGF-1 level at 1 and 2 years ( 7.3 % to 8.0 % , p < .05 ) . Our study showed that in protein-replete healthy ambulant women , 30 g of extra protein increased IGF-1 but did not have beneficial or deleterious effects on bone mass or strength . The effect of protein supplementation in population s with low dietary protein intake requires urgent attention Milk contains several components effective for bone health . In the previous in vitro and in vivo studies , we have shown that milk whey protein , especially its basic protein fraction ( milk basic protein [ MBP ] ) , promoted bone formation and suppressed bone resorption . This present study examines the effect of MBP on the biochemical markers of bone metabolism in healthy adult men .  Experimental beverages containing MBP ( 300 mg of MBP a day ) were given to 30 normal healthy adult men for 16 days . The serum osteocalcin concentration had increased significantly after 16 days of ingesting the experimental beverage containing MBP .  Urinary cross-linked N-teleopeptides of type-I collagen ( NTx ) excretion had decreased significantly after 16 days of ingesting MBP . The urinary NTx excretion was related to the serum osteocalcin concentration after 16 days of ingestion . These results suggest that MBP promoted bone formation and suppressed bone resorption , while maintaining the balance of bone remodeling Fracture of the proximal femur is the most dramatic clinical sequela of osteoporosis [ 1 , 2 ] . It is associated with a high mortality rate , need for long-term medical care , and prolonged disability [ 3 - 5 ] . Protein malnutrition is often seen in elderly persons and is more severe in patients with hip fracture [ 6 - 11 ] . Protein deficiency may contribute to the occurrence of hip fracture by reducing muscle strength , impairing movement coordination , and diminishing the protective layer of soft tissue padding [ 9 , 10 , 12 - 14 ] It may also be associated with lower bone mineral density at the proximal femur [ 15 ] . Furthermore , malnutrition in general and protein deficiency in particular at admission and during recovery may adversely influence clinical outcome after hip fracture [ 7 , 9 , 10 , 16 - 18 ] . Protein restriction has been shown to reduce plasma levels of insulin-like growth factor-I ( IGF-I ) by inducing resistance to the action of growth hormone in the liver and increasing the metabolic clearance rate of the growth factor [ 19 - 23 ] . Furthermore , evidence shows that protein depletion may blunt the effect of IGF-I on target organs [ 20 ] . Thus , low protein intake in elderly persons may be detrimental to skeletal integrity , muscle strength , and immune response [ 11 , 24 - 27 ] because of decreased production and action of IGF-I , which favorably influences these systems [ 28 - 33 ] . Previous studies [ 16 , 17 ] have shown that a 5-week course of protein supplements can reduce the medical complication rate and duration of hospital stay in patients with recent hip fracture . These findings were independent of energy , calcium , and vitamin D intake [ 17 ] . Whether these observations were related to the restoration of decreased IGF-I levels and whether bone may benefit from long-term protein supplementation are not known . We investigated whether protein supplements in vitamin D-replete patients with a recent hip fracture who were receiving calcium supplements could increase circulating IGF-I levels and favorably influence bone mineral density . Methods Patients Patients were recruited in the orthopedic ward of Geneva University Hospital , the referral center that receives 94.6 % of all patients with hip fracture from an area with a population of approximately 400 000 persons [ 5 ] . The protocol was approved by the ethical committee of the Geneva University Hospital Department of Surgery . Inclusion criteria were age greater than 60 years ; recent hip fracture ( within 2 weeks ) attributable to osteoporosis ( that is , a fracture after a minor trauma , such as a fall from st and ing height ) ; and the ability to give written , informed consent . Exclusion criteria were pathologic fracture ; fracture caused by severe trauma ; history of contralateral hip fracture ; severe mental impairment ; active metabolic bone disease ; renal failure ( plasma creatinine concentration 200 mol/L ) ; acute illness that could interfere with the study protocol ; severe malnutrition ( serum albumin level < 15 g/L ) ; consumption of drugs known to alter bone metabolism , such as calcitonin , fluoride , sex hormones , corticosteroids , or bisphosphonates ; and life expectancy of less than 1 year . Using a r and om number table , we assigned patients to receive an oral protein supplement composed of 90 % milk proteins or a placebo made isocaloric by the addition of maltodextrins . Patients took the assigned intervention 5 days a week for 6 months in addition to their regular diet . All patients received one oral dose of vitamin D3 , 200 000 IU ( vitamine D3B.O.N. , Doms-Adrian , Courbevoie , France ) , to correct any possible vitamin D deficiency [ 34 ] . The daily protein supplement ( Meritene , S and oz Nutrition Ltd. , Berne , Switzerl and ) provided 1050 kJ ( 250 kcal ) of energy in the form of 20 g of proteins , 3.1 g of lipids , and 35.7 g of carbohydrates ( 54.4 g in placebo ) . The other constituents of the 65 g powder supplement were vitamin A ( 1000 IU ) , vitamin K1 ( 30 g ) , vitamin C ( 20 mg ) , calcium ( 550 mg ) , magnesium ( 91 mg ) , phosphorus ( 429 mg ) , and sodium ( 228 mg ) . The supplement is design ed to normalize but not overcompensate for the insufficient dietary intake of protein of elderly persons with a recent fracture of the proximal femur [ 16 ] . Compliance was verified by weekly phone calls and by counting the remaining nutritional supplement bags , which were forwarded monthly by mail . Clinical Data Medical history , clinical characteristics , anthropometric data , and performance status according to an Activities of Daily Living score [ 35 ] were evaluated . Dietary intakes were recorded by using a food-frequency question naire [ 36 ] about the week before the fracture . Food intakes were analyzed by using a nutrient software system ( Fruitdor , Astra-Calve , Paris , France ) . Dietary intake of calcium , phosphorus , and protein was calculated from intake of dairy products , meat , fish , and vegetables . Because many patients were unable to st and a few days after hip fracture , their height was determined with a fathom measure while they were recumbent . Body weight was determined with a scale that correlated highly with that provided by measurement of whole body bone , fat , and lean mass as assessed by dual x-ray absorptiometry [ 37 ] . Mid-arm circumference was measured with a tape measure ( coefficient of variation , 2 % ) . Isometric muscle strength of the biceps of the dominant arm was evaluated with a dynamometer ( Lido , Lidoactive Isokinetic System , Loredan Biomedical Inc. , West Sacramento , California ) , which measures the peak torque ( coefficient of variation < 5 % ) . The grip strength of the same arm was measured with a dynamometer ( Vigorimeter , Martin Medizin-Technik , Tuttlingen , Germany ) [ 38 ] . The mean of three measurements was used for calculation . Biochemical Data Within 120 hours after surgery , we used st and ard methods to analyze venous blood sample s for protein-corrected plasma levels of calcium , phosphate , creatinine , total proteins , albumin , and prealbumin . We also measured levels of IGF-I ( Nichols Institute , San Juan Capistrano , California ) after acid-ethanol extraction and cryoprecipitation [ 39 ] , intact parathyroid hormone ( Immulite , Diagnostic Products , Los Angeles , California ) , calcitriol , calcidiol ( Incstar , Stillwater , Minnesota ) , and osteocalcin ( CIS-BIO International , Gif-sur-Yvette , France ) . Biochemical measurements were repeated 6 and 12 months after the fracture . Serum IGF-I binding proteins were measured by Western lig and blot analysis [ 40 ] . Briefly , 3 L of serum was boiled and separated onto 15 % sodium dodecylsulfate polyacrilamide gel electrophoresis under nonreducing conditions . Proteins were electrically blotted onto a nitrocellulose membrane , and IGF-I binding proteins were detected after incubating the membranes with radioiodinated IGF-I at 4C for 24 hours . Insulin-like growth factor binding proteins were quantified by phosphorimaging ( Molecular Dynamics , Sunnyvale , California ) . The intensity of the b and s corresponding to the appropriate molecular weights [ 40 ] was expressed as the percentage of total bound radioactive IGF-I. Measurements of calcium , phosphate , and creatinine were obtained from the second fasting morning urine . The ratio of hydroxyproline to creatinine in the same sample was taken as a reflection of bone resorption . Markers of bone resorption ( pyridinoline and deoxypyridinoline ) in the first morning spot urine were measured by detecting fluorescence emission after acid hydrolysis and separation with isocratic reverse-phase high-performance liquid chromatography ( BioRad System , Munich , Germany ) , and the values were adjusted to the creatinine concentration . Immunologic Data Concentrations of IgA , IgG , IgM , and isohemagglutinins were measured by using st and ard methods . Cell-mediated immunity was assessed by using a skin-test antigens for cellular hypersensitivity system ( STACH , Institut Merieux , Lyon , France ) , which evaluates the size of the skin reaction to various antigens injected intradermally [ 41 ] . Bone Mass Assessment We measured areal bone mineral density at the lumbar spine ( anteroposterior and lateral views ) , the contralateral proximal femur ( femoral neck and trochanter ) , and the contralateral mid-femoral shaft . We also measured whole-body bone mineral content , fat , and lean mass by using dual x-ray absorptiometry ( Hologic QDR-2000 , Waltham , Massachusetts ) . The coefficients of variation of these measurements are reported elsewhere [ 37 , 42 ] . Vertebral Deformity Two series of lateral radiography of the thoracic and lumbar spine were taken at the start of the study and at 12 months . The films were examined by a single investigator ( who was unaware of treatment group assignment ) according to a 6-point analysis procedure for each vertebral body from T4 to L4 [ 43 , 44 ] ( intra-observer coefficient of variation , 1.8 % to 3.1 % ) . At baseline , fracture was defined by a decrease of 20 % in the ratio of anterior or middle height to posterior height . Patients were considered to have a new vertebral deformity if the anterior , middle , or posterior height decreased by more than 20 % between the two examinations . Statistical Analysis All values are given as the mean SD for baseline measurement and the mean SE for comparisons of outcome results . All analyses were performed by using the SAS procedure ( Cary , North Carolina ) . One-way analysis of variance was used . A two-tailed P value less than 0.05 was considered significant . Role of the Funding Sources This study was supported by grants from S and oz Nutrition Ltd. , Berne , Switzerl and , and the Swiss National Research Science Foundation . The skin-test antigens for cellular hypersensitivity system was supplied by Rhone-Poulenc , Thalwil , Switzerl and . No organization influenced the design , conduct , or reporting of the study . Results Of 842 patients evaluated from April 1992 to February 1994 , 82 were recruited into the r and omized , double-blind , placebo-controlled trial . This low enrollment rate was due to patients ' poor medical or cognitive conditions and reluctance to give informed consent . It has been suggested that bone health in adulthood is programmed by development in utero . Most previous investigations addressing this topic have focussed on bone mineral density or content , rather than other indicators of bone health , such as biochemical markers of bone turnover . This study investigated whether potential predictors , from different stages of life , influence bone resorption in men aged 49 - 51years in the Newcastle Thous and Families birth cohort . The cohort originally consisted of all 1142 births in the city of Newcastle upon Tyne , UK in May and June 1947 . Detailed information was collected prospect ively during childhood , including birth weight and socio-economic circumstances . At 49 - 51years of age , 574 study members completed a detailed ' Health and Lifestyle ' question naire , including the European Prospect i ve Investigation of Cancer ( EPIC ) food frequency question naire and 412 study members attended for clinical examination , including 172 men in whom bone resorption was assessed by measurement of serum beta C-telopeptide of type 1 collagen ( CTX ) .  A significant trend was seen between increasingly disadvantaged socio-economic status at birth and increased bone resorption ( p=0.04 , r-squared 2.6 % ) . However , birth weight , st and ardised for sex and gestational age , was not associated with serum CTX ( p=0.77 , r-squared 0.05 % ) . Significant trends were also seen between increasing total energy intake ( p=0.03 , r-squared 2.9 % ) , dietary intake of saturated fat ( p=0.02 , r-squared 2.6 % ) , protein ( p=0.04 , r-squared 2.5 % ) and carbohydrates ( p=0.04 , r-squared 2.6 % ) and higher serum CTX . However , on adjustment for total energy intake , none of the other dietary variables was significant at the univariate level maintained significance . Our findings suggest that early socio-economic disadvantage and later dietary factors may be associated with increased  bone resorption in middle aged men . However , as little of the variance in serum CTX was explained by the variables included within this investigation , further longitudinal studies , with sufficient statistical power , are required to assess predictors of bone resorption in adulthood and their relative importance AIM To compare the nutritional status and dietary intake of elderly women admitted with hip fracture ( HF ) versus a control group without fracture and without known abnormalities of bone mineral density . DESIGN Descriptive and observational study . LOCATION Hospital Neurotraumatológico in Jaen ( Spain ) and three urban Primary Health Care centers in Jaen city ( San Felipe , Virgen de la Capilla and El Valle ) . PARTICIPANTS A total of 44 women with HF , which was considered osteoporotic , and a control group composed of 42 women with a similar age range , selected r and omly from the medical out patients who visit their Primary Health Care centers . MEASUREMENTS We record sociodemographic data . Dietary intake before the fracture and anthropometric variables  in the first 72hours after admission were assessed . RESULTS Patients with HF had lower weight ( 67.2±10.1 kg versus 72.0±10.1 kg , P<.05 ) , BMI ( 27.6±3.7kg/m(2 ) versus 31.3±4.6kg/m(2 ) , P<.001 ) , as well as lower arm and leg circumferences than the control patients . A significantly higher intake , in terms of macronutrients and energy consumption , was detected in the control group , as well as lower than recommended intake of calcium and vitamin D in both groups , which was more marked in patients with HF . Logistic regression found that the HF was associated with a lower BMI as well as lower intakes of protein , carbohydrates and calcium . CONCLUSIONS Adequate nutritional status and adequate intake of essential macro- and micronutrients seem to prevent osteoporotic HF Almost 30 % of hip fractures occur in men ; the mortality , morbidity , and loss of independence after hip fractures are greater in men than in women . To comprehensively evaluate risk factors for hip fracture in older men , we performed a prospect i ve study of 5994 men , primarily white , age 65 + years recruited at six US clinical centers . During a mean of 8.6 years of 97 % complete follow-up , 178 men experienced incident hip fractures . Information on risk factors including  femoral neck bone mineral density ( FNBMD ) was obtained at the baseline visit . Cox proportional hazards models were used to calculate the hazard ratio ( HR ) with 95 % confidence intervals ; Fine and Gray models adjusted for competing mortality risk . Older age ( ≥75 years ) , low FNBMD , currently smoking , greater height and height loss since age 25 years , history of fracture , use of tricyclic antidepressants , history of myocardial infa rct ion or angina , hyperthyroidism or Parkinson 's disease , lower protein intake , and lower executive function were all associated with an increased hip fracture risk . Further adjustment for competing mortality attenuated HR for smoking , hyperthyroidism , and Parkinson 's disease . The incidence rate of hip fracture per 1000 person-years ( PY ) was greatest in men with FNBMD T-scores < -2.5 ( white women reference data base ) who also had 4 + risk factors , 33.4 . Men age ≥80 years with 3 + major comorbidities experienced hip fracture at rates of 14.52 versus 0.88 per 1000 PY in men age < 70 years with zero comorbidities . Older men with low FNBMD , multiple risk factors , and multimorbidity have a high risk of hip fracture . Many of these assessment s can easily be incorporated into routine clinical practice and may lead to improved risk stratification . © 2016 American Society for Bone and Mineral Research We studied the effects of daily intake of milk basic protein ( MBP ) on radial bone mineral density ( BMD ) in healthy adult women . Thirty-three healthy women were r and omly assigned to a 6-month trial with either placebo or MBP ( 40 mg per day ) . The radial BMD of each volunteer was measured at the beginning of and at six months after the trial . The mean BMD value at the 6th month in the MBP group increased significantly at both 1/6 and 1/10 portion from the distal end of the radius , whereas that in the control group did not . The BMD gain of each volunteer in the MBP group was significantly higher than that in the placebo group . Thus a daily MBP supplementation of 40 mg in healthy adult women can significantly increase radial BMD 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
target: There appears to be little benefit of increasing protein intake for bone health in healthy adults but there is also clearly no indication of any detrimental effect , at least within the protein intakes of the population s studied ( around 0.8–1.3 g/Kg/day ) .
background: We undertook a systematic review and meta- analysis of published papers assessing  dietary protein and bone health .
  We found little benefit of increasing protein intake for  bone health in healthy adults but no indication of any detrimental effect , at least within the protein intakes of the population s studied .
  This systematic review and meta- analysis analysed the relationship between dietary protein and bone health across the life-course .