Effect of Dietary Protein Intake on Bone Mineral Density and Fracture Incidence in Older Adults in the Health, Aging, and Body Composition Study

Associations of protein intake with the risk of fractures: A prospective cohort study of UK biobank participants

PURPOSE

To evaluate the associations between protein intake and fractures risk in a large population-based cohort.

METHODS

We conducted a prospective population-based study of UK Biobank. Participants aged 40-69 who completed the Oxford WebQ dietary questionnaire at least once were included. Exposures were percentage of energy provided by protein and its components (animal and vegetable protein). Participants were categorized into quintiles based on these exposures. The primary outcome was composite fracture, and secondary outcomes included osteoporotic and hip fractures, defined by ICD-10 codes. We used Cox proportional hazard models and restricted cubic splines (RCS) to assess the association between exposure and outcomes, as well as their dose-response relationships.

RESULTS

This study included 132,807 participants (mean [SD] age, 56.8 [8.0] years; 68,769 [51.8 %] female). During a median follow-up of 12.4 years, 6,673 composite fractures, 4,496 osteoporotic fractures and 930 hip fractures occurred. Regarding protein intake, compared to the lowest quintile (Q1), individuals in the highest quintile (Q5) had significantly lower risks of composite fracture (HR 0.82, 95 % CI 0.75-0.90), osteoporotic fracture (HR 0.81, 95 % CI 0.72-0.91) and hip fracture (HR 0.63, 95 % CI 0.49-0.82). Similar results were observed for animal and vegetable protein intake. RCS revealed a negative linear dose-response relationship between protein intake and fractures risk.

CONCLUSION

Increased protein intake can significantly reduce the risk of fractures and may serve as an important dietary strategy for promoting bone health.

Association between dietary protein intake and bone mineral density in adolescents: a cross-sectional study

Elevated daily protein consumption was significantly correlated with enhanced bone mineral density (BMD) across multiple skeletal sites in adolescents, as observed in the National Health and Nutrition Examination Survey. These results highlight the pivotal role of dietary protein in fostering bone health in the youth.

BACKGROUND

The relationship between dietary protein intake and bone mineral density (BMD) remains inconclusive, particularly among adolescents. This study aimed to investigate the association between dietary protein intake and BMD in adolescents.

METHODS

This cross-sectional study utilized data from 12-19-year-old participants in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2010. Average daily protein intake was calculated from two consecutive 24-h dietary recalls. Dual-energy X-ray absorptiometry (DXA) was used to evaluate the BMD of the total femur, femoral neck, total spine, and lumbar spine. Multivariate linear regression was used to evaluate the association between dietary protein intake and BMD, adjusted for dietary protein intake per 10 g/day and multiple covariates. Stratified analysis, interaction analysis, and sensitivity analysis were performed to assess the consistency of this relationship and identify potential modifiers.

RESULTS

After excluding missing data, the analysis included 2,640 adolescents. In the fully adjusted model, dietary protein intake showed a significant positive association with both total femur BMD (per 10 g/d: β = 5.25, 95% Cl = 1.69 ~ 8.82) and femoral neck BMD(per 10 g/d: β = 5.23, 95% Cl = 1.56 ~ 8.89). This positive association between dietary protein intake and BMD persisted in sensitivity analyses after multiple interpolation with all covariates missing. Subgroup analyses found no interaction between subgroups, or interaction results showed no clinical significance.

CONCLUSION

This study suggests that higher dietary protein intake is associated with increased BMD in US adolescents, highlighting the potential role of protein in adolescent bone health.

Association between dietary protein intake and bone mineral density based on NHANES 2011-2018

This study examines the relationship between dietary protein intake and bone mineral density (BMD) using data from the 2011-2018 National Health and Nutrition Examination Survey (NHANES), addressing existing controversies in current evidence. This cross-sectional study included 16,775 participants. Dietary protein intake, the exposure variable, was collected with the use of two 24-h dietary recall methods and usual intake was assessed by the National Cancer Institute (NCI) method. While whole-body BMD, the outcome variable, was measured with dual-energy X-ray absorptiometry. Covariates included demographic, socioeconomic, and health factors. Weighted multivariable regression and generalized additive models were used for the association between dietary protein intake and BMD. After adjusting for covariates, a positive association was found between protein intake and BMD. Each additional gram of protein consumed was significantly associated with a BMD increase of 0.0003 g/cm2 (95% CI 0.0001, 0.0004, P = 0.0003). Subgroup analysis by gender and ethnicity revealed significant positive correlations in women and Mexican Americans. Additionally, a saturation threshold effect was observed in women at 60.70 g/day and in non-Hispanic whites at 135.53 g/day, where the correlation was no longer significant beyond these thresholds. The study demonstrates a positive association between dietary protein intake and BMD, although this relationship is complex and nonlinear with varying effects across different populations. Specifically, positive correlation is only significant below a specific threshold level in some populations. These findings suggest the need for personalized dietary guidelines and provide important insights for clinical nutritional interventions and bone health management.

The Effect of Protein Intake on Bone Disease, Kidney Disease, and Sarcopenia: A Systematic Review

Background

Protein is essential for optimal growth, function, and maintenance of health. Its impact on bone, kidney health, and sarcopenia progression remains debated.

Objectives

This review examines the association between dietary protein intake and the risk of bone disease, kidney disease, and sarcopenia to inform protein dietary reference intake updates.

Methods

We searched Medline, EMBASE, AGRICOLA, and Scopus from January 2000 to May 2024, supplemented by citation searching for relevant reviews and original research. We included randomized and nonrandomized controlled trials, prospective cohort studies, and nested case-control studies examining dietary protein intake without exercise. We assessed the risk of bias (RoB), performed a qualitative synthesis of low to moderate RoB studies, and evaluated the strength of evidence.

Results

Of 82 articles detailing 81 unique studies, only 13 were assessed with low to moderate RoB and synthesized, comprising bone disease [4 randomized controlled trials (RCTs) and 1 prospective cohort study], kidney disease (1 RCT), and sarcopenia (9 RCTs). The overarching evidence was insufficient, largely due to the limited number of low to moderate RoB studies, the diversity of dietary protein interventions, and the broad range of outcomes, which complicated synthesis and comparison. Notably, sparse literature addressed children and adolescents, and only a single study each examined the impact of dietary protein intake on bone disease risk (yielding mixed findings) in these populations and on kidney disease risk (showing no significant effects) in adults. The findings on the impact of protein intake on bone disease in adults and sarcopenia risk were mixed; some studies showed no effect, whereas others indicated benefits.

Conclusions

The evidence since 2000 on associations between dietary protein intake and the risks of bone disease, kidney disease, and sarcopenia is unclear, indicating a need for more rigorous research.This trial was registered at PROSPERO as CRD42023446621.

Management of Osteoporosis in Parkinson's Disease: A Systematic Review of Clinical Practice Guidelines

BACKGROUND

Parkinson's disease (PD) is the fastest-growing neurological disorder globally. Defining features include tremor, muscular rigidity, bradykinesia, and postural instability, which in combination with nonmotor symptoms such as cognitive impairment and orthostatic hypotension increase the risk of falls. Along with low bone mineral density, fracture risk is high in PD.

OBJECTIVES

The aims were to identify and appraise clinical practice guidelines, consensus statements, and treatment algorithms containing recommendations for bone health in people with PD (PwP).

METHODS

We systematically searched 4 electroninc databases (MEDLINE, Embase, Emcare, and Web of Science) (n = 78), in addition to the websites of organizations, societies, and professional bodies focused on PD or osteoporosis (n = 28), up to April 22, 2024.

RESULTS

After duplicate removal, screening, and full-text review, 6 records were included. Included records were appraised using the AGREE II (Appraisal of Guidelines for Research and Evaluation) tool. All records recognized bone health as a concern in PD, yet recommendations for fracture-risk screening were inconsistent. Two of six records grouped PD under the broad category of neurological diseases. The acceptability and tolerance of anti-osteoporosis medications in PwP was discussed only in 1 record, which incorporated national osteoporosis guidelines into a PD-specific treatment algorithm.

CONCLUSIONS

This review highlights that despite the documented high fracture rates of PwP, health professionals do not always have adequate resources to support them when considering how to manage osteoporosis. Osteoporosis screening and management needs to be incorporated into PD treatment guidelines, and equally providing specific recommendations for PwP related to bone health in national osteoporosis guidelines should be a priority given the high burden of fracture in the patient population.

Dairy and Exercise for Bone Health: Evidence from Randomized Controlled Trials and Recommendations for Future Research

PURPOSE OF REVIEW

To examine evidence from randomized controlled trials (RCTs) on how modifiable factors such as exercise and nutrition, with a focus on dairy products, play a role in improving bone health across the lifespan.

RECENT FINDINGS

Meta-analyses of RCTs demonstrate the advantages of consuming dairy products to improve bone mineral density/content (BMD/BMC) and markers of bone metabolism and turnover (BTMs). Eighteen RCTs were conducted investigating the combined effects of dairy and exercise, with most indicating a benefit in youth and adult populations. Results were less conclusive in older adults, perhaps due to altered requirements for dairy/nutrients and exercise with increased age.   RCTs demonstrate that dairy product consumption alone benefits bone health and can enhance the effects of exercise on bone. This may help improve skeletal growth and development in adolescence and prevent osteoporosis with increased age. Future RCTs should account for habitual nutrient intakes, and dairy dosage, timing, and matrix effects.

Reversal of Bone Mineral Density Loss Through Lifestyle Changes: A Case Report

Approximately 10 million individuals in the United States have osteoporosis and 44 million have low bone mineral density which puts them at risk for bone breaks. This presents a large burden on our health care system since about one-quarter of hip fracture patients never regain full function, need nursing care, and, for those over age 50, 24% die within one year. Oral bisphosphonates are often used as first-line therapy for the treatment of osteoporosis; however, patients frequently experience significant side effects. In addition, bisphosphonates inhibit bone loss by initiating apoptosis in osteoclasts that remove old bone, thus allowing old bone to accumulate and slowing the activity of osteoblasts that create new bone, thereby affecting bone quality. As an alternative, a bone-friendly lifestyle, including calcium and vitamin D consumption, exercise, smoking cessation, and a decrease in alcohol intake, may reduce bone loss. This case report describes lifestyle changes that included diet and exercise that increased bone mineral density in two years in a post-menopausal woman with no negative side effects.

Identification of nutrition factors in the metabolic syndrome and its progression over time in older adults: analysis of the TUDA cohort

BACKGROUND

Nutrition is recognized as playing an important role in the metabolic syndrome (MetS), but the dietary components involved are unclear. We aimed to investigate nutrition factors in relation to MetS and its progression in older adults over a follow-up period of 5.4 years.

METHODS

Community-dwelling adults (≥ 60y) from the Trinity-Ulster-Department-of-Agriculture study, sampled at baseline (2008-12) and follow-up (2014-18; n 953), were classified as 'with MetS' by having three or more of: waist circumference (≥ 102 cm, males; ≥ 88 cm, females); HDL-cholesterol (< 1.0 mmol/L, males; < 1.3 mmol/L, females); triglycerides (≥ 1.7 mmol/L); blood pressure (systolic ≥ 130 and/or diastolic ≥ 85 mmHg); and hemoglobin A1c (≥ 39 mmol/mol).

RESULTS

MetS was identified in 67% of participants, increasing to 74% at follow-up. Predictors at baseline for the development of metabolic syndrome (MetS) at follow-up were higher waist circumference (odds ratio [95%CI]; 1.06 [1.01-1.11]), but not BMI, and increased triglyceride concentrations (2.01 [1.29-3.16]). In dietary analysis (at follow-up), higher protein (g/kg bodyweight/day) and monounsaturated fatty acid (g/day) intakes were each associated with lower risk of MetS (0.06 [0.02-0.20] and 0.88 [0.78-1.00], respectively), whilst higher protein was also associated with lower abdominal obesity (0.10 [0.02-0.51]) and hypertension (0.22 [0.00-0.80]). Furthermore, participants with, compared to without, MetS consumed less high-quality protein foods (P = 0.006) and more low-quality protein foods (P < 0.001), as defined by the protein digestibility-corrected amino acid score.

CONCLUSIONS

Dietary interventions targeting protein quantity and quality may have specific benefits in preventing or delaying the progression of MetS in at-risk older people, but this requires investigation in the form of randomized trials.

Discussion on protein recommendations for supporting muscle and bone health in older adults: a mini review

Muscle and bone tissues are interconnected, and both rely on an adequate protein intake. Recommendations for protein intake for older adults specifically vary across countries. The purpose of this narrative review is to discuss the existing evidence for protein recommendations for supporting muscle and bone health in older adults and to evaluate if a protein intake above the current population reference intake (PRI) for older adults would be scientifically justified. First, this review summarizes the protein recommendations from bodies setting dietary reference values, expert groups, and national health organizations. Next, relevant studies investigating the impact of protein on muscle and bone health in older adults are discussed. In addition, the importance of protein quality for muscle and bone health is addressed. Lastly, a number of research gaps are identified to further explore the added value of a protein intake above the PRI for older adults.

Three-Year Mortality of Older Hospitalized Patients with Osteosarcopenia: Data from the OsteoSys Study

Osteosarcopenia, the concurrent presence of sarcopenia and osteopenia/osteoporosis, poses a significant health risk to older adults, yet its impact on clinical outcomes is not fully understood. The aim of this prospective, longitudinal multicentre study was to examine the impact of osteosarcopenia on 3-year mortality and unplanned hospitalizations among 572 older hospitalized patients (mean age 75.1 ± 10.8 years, 78% female). Sarcopenia and low bone mineral density (BMD) were evaluated using Dual Energy X-ray Absorptiometry and the European Working Group on Sarcopenia in Older People (EWGSOP2) and WHO criteria, respectively. Among participants, 76% had low BMD, 9% were sarcopenic, and 8% had osteosarcopenia. Individuals with osteosarcopenia experienced a significantly higher rate of mortality (46%, p < 001) and unplanned hospitalization (86%, p < 001) compared to those without this condition. Moreover, "healthy" subjects-those without sarcopenia or low BMD-showed markedly lower 3-year mortality (9%, p < 001) and less unplanned hospitalization (53%, p < 001). The presence of osteosarcopenia (p = 0.009) increased the 3-year mortality risk by 30% over sarcopenia alone and by 8% over low BMD alone, underscoring the severe health implications of concurrent muscle and bone deterioration. This study highlights the substantial impact of osteosarcopenia on mortality among older adults, emphasizing the need for targeted diagnostic and therapeutic strategies.

The multi-faceted nature of age-associated osteoporosis

Age-associated osteoporosis (AAOP) poses a significant health burden, characterized by increased fracture risk due to declining bone mass and strength. Effective prevention and early treatment strategies are crucial to mitigate the disease burden and the associated healthcare costs. Current therapeutic approaches effectively target the individual contributing factors to AAOP. Nonetheless, the management of AAOP is complicated by the multitude of variables that affect its development. Main intrinsic and extrinsic factors contributing to AAOP risk are reviewed here, including mechanical unloading, nutrient deficiency, hormonal disbalance, disrupted metabolism, cognitive decline, inflammation and circadian disruption. Furthermore, it is discussed how these can be targeted for prevention and treatment. Although valuable as individual targets for intervention, the interconnectedness of these risk factors result in a unique etiology for every patient. Acknowledgement of the multifaceted nature of AAOP will enable the development of more effective and sustainable management strategies, based on a holistic, patient-centered approach.

Association between total and animal proteins with risk of fracture: A systematic review and dose-response meta-analysis of cohort studies

Previous cohort studies have indicated that consumption of total and animal proteins are related to fracture risk; however, results were inconclusive. This dose-dependent review sought to summarize the earlier evidence regarding the relation between total and animal proteins and fracture risk. We searched Scopus, PubMed, and Web of Science until July 2023 for original research articles examining the association of certain types of proteins and the incidence of all fractures in general adults. Summary relative risks (RRs) were calculated using random effects analysis to examine the relation between each certain amount (g/day) increment of total and animal protein and fracture risk. Twenty cohort studies with serious to moderate risk of bias involving 780,322 individuals were included. There was a non-statistically significant relation between intake of animal proteins and dairy products and all fracture risk. However, 43% and 5% decreased incidence of fracture was obtained with total protein (RR, 0.57; 95%CI, 0.36 to 0.93; per 100 g/day) and fish (RR, 0.95; 95%CI, 0.91 to 0.99; per 15 g/day) intake. Every 100 g/day total and animal protein consumption and every 15 g/day fish consumption were linked to 48%, 50%, and 5% lower hip fracture risk. Greater dietary animal protein intake might reduce risk of hip but not fracture at any site. We obtained a lower risk of any or hip fracture with greater total protein (per 100 g/day) and fish (per 15 g/day) intake. No evidence was obtained that higher intake of dairy could decrease risk of fracture.

Determinant factors of bone health after long-term of Roux-en-Y gastric bypass surgery: A cross-sectional study

OBJECTIVES

The aim of this study was to evaluate bone health and the potential influencing factors of bone metabolism disorders in adults ≥5 y after Roux-en-Y gastric bypass (RYGB) surgery.

METHODS

In this cross-sectional study, patients who were ≥5 y post-RYGB were invited. Bone health considered as bone mineral content (BMC) and bone mineral density (BMD) in this study was assessed by dual x-ray absorptiometry. We also assessed 25-hydroxy-vitamin D concentrations, individual ultraviolet B radiation levels, serum ionized calcium, alkaline phosphatase, parathyroid, anthropometric, and body composition.

RESULTS

The study evaluated 104 adults (90% women; 49.6 ± 9.1 y old; postoperative period 8.7 ± 2.2 y). Lumbar and femoral BMC and BMD were positively correlated to body mass index (BMI), appendicular lean mass (ALM), and negatively to %excess of weight loss (EWL). Femoral BMD was negatively correlated to age, and both femoral BMD and BMC were positively correlated to weekly exposed body part score. Sex, age, BMI, ALM, and weekly exposed body part score explained 35% and 54% of the total variance of femoral BMD and BMC, respectively.

CONCLUSIONS

The present findings suggested that older age, lower BMI, higher %EWL, lower ALM, and lower weekly body part exposure score are important determinants in lowering BMD and BMC parameters in long-term post-bariatric surgery individuals, rather than serum 25-hydroxy-vitamin D and parathyroid.

Protein intake and bone mineral density: Cross-sectional relationship and longitudinal effects in older adults

BACKGROUND

There are several mechanisms via which increased protein intake might maintain or improve bone mineral density (BMD), but current evidence for an association or effect is inconclusive. The objectives of this study were to investigate the association between dietary protein intake (total, plant and animal) with BMD (spine and total body) and the effects of protein supplementation on BMD.

METHODS

Individual data from four trials that included either (pre-)frail, undernourished or healthy older adults (aged ≥65 years) were combined. Dietary intake was assessed with food records (2, 3 or 7 days) and BMD with dual-energy X-ray absorptiometry (DXA). Associations and effects were assessed by adjusted linear mixed models.

RESULTS

A total of 1570 participants [57% women, median (inter-quartile range): age 71 (68-75) years] for which at least total protein intake and total body BMD were known were included in cross-sectional analyses. In fully adjusted models, total protein intake was associated with higher total body and spine BMD [beta (95% confidence interval): 0.0011 (0.0006-0.0015) and 0.0015 (0.0007-0.0023) g/cm² , respectively]. Animal protein intake was associated with higher total body and spine BMD as well [0.0011 (0.0007-0.0016) and 0.0017 (0.0010-0.0024) g/cm² , respectively]. Plant protein intake was associated with a lower total body and spine BMD [-0.0010 (-0.0020 to -0.0001) and -0.0019 (-0.0034 to -0.0004) g/cm² , respectively]. Associations were similar between sexes. Participants with a high ratio of animal to plant protein intake had higher BMD. In participants with an adequate calcium intake and sufficient serum 25(OH)D concentrations, the association between total protein intake with total body and spine BMD became stronger. Likewise, the association between animal protein intake with total body BMD was stronger. In the longitudinal analyses, 340 participants [58% women, median (inter-quartile range): age 75 (70-81) years] were included. Interventions of 12 or 24 weeks with protein supplementation or protein supplementation combined with resistance exercise did not lead to significant improvements in BMD.

CONCLUSIONS

An association between total and animal protein intake with higher BMD was found. In contrast, plant protein intake was associated with lower BMD. Research is warranted to further investigate the added value of dietary protein alongside calcium and vitamin D for BMD improvement, especially in osteopenic or osteoporotic individuals. Moreover, more research on the impact of a plant-based diet on bone health is needed.

Associations between Macronutrients Intake and Bone Mineral Density: A Longitudinal Analysis of the Health Workers Cohort Study Participants

OBJECTIVE

This study aimed to evaluate the association between macronutrient intake and bone mineral density (BMD) using non-substitution and substitution statistical approaches.

DESIGN

Longitudinal analysis.

SETTINGS AND PARTICIPANTS

1,317 adults in the Health Worker Cohort Study in Mexico.

MEASUREMENTS

These participants were assessed at baseline (2004-2006) and follow-up (2010-2012). Dietary intakes were assessed using validated food frequency questionnaires. BMD at the different sites was performed by dual-energy X-ray absorptiometry (DXA). Hybrid-mixed effects regression models were performed to evaluate the associations of interest.

RESULTS

Cross-sectional associations were found between fiber intake and higher total hip and femoral neck BMD in women and longitudinal associations with loss of femoral neck BMD in men. An increase in 5% energy intake from carbohydrate was associated with a BMD loss at several site in women and total hip and femoral neck in men. In both sexes, an increase in 5% energy intake of animal protein or fat was associated with a site-specific BMD gain after six years. Substitution analysis showed that the energy intake replacement from fat or carbohydrate by protein had an increase in BMD at different sites in women; while in men, it was only significant when replacing carbohydrate. Substitution of protein or fat by carbohydrates was associated with lower BMD in women, and only protein replacement by carbohydrates in men.

CONCLUSION

Our findings suggest that carbohydrate intake was associated with loss of BMD, while animal protein and fat intake was associated with gain of BMD among the Mexican population. Macronutrient substitutions resulted in significant associations; however, additional studies are needed to confirm these findings.