Animal versus plant protein and adult bone health: A systematic review and meta-analysis from the National Osteoporosis Foundation

Quality improvement of threadfin bream (Nemipterus virgatus) surimi-gel using soy protein as a natural food additive

Previously, we identified sarcoplasmic serine proteinase (SSP) as a modori-inducing proteinase from threadfin bream belly muscle. In this study, we investigated the autolytic activity of commercial threadfin bream surimi under modori-inducing conditions. High autolytic activity was detected in commercial surimi and was inhibited by a soybean trypsin inhibitor, indicating that SSP still remained in the commercial surimi. The effects of soy protein, defatted soy protein (DSP) and isolated soy protein (ISP), on SSP activity and surimi-gel properties were evaluated. The results showed that the modori phenomenon was induced at 70 °C, and that both DSP and ISP suppressed SSP activity and strengthened the breaking strength and breaking distance of the modori-induced gel. Surimi-gel with DSP performed better on gel whiteness than that of ISP, and 1 g/kg DSP had optimal gel properties. In conclusion, soy protein proved to be a good natural food additive for surimi-gel production of threadfin bream.

Bone mineral density and body composition in Australians following plant-based diets vs. regular meat diets

Background and aims

Bone mineral density (BMD) and body composition play an important role in maintaining metabolic health and physical functioning. Plant-based diets (PBDs) are known to be lower in protein and calcium, which can impact BMD and body composition. This study aimed to investigate the relationship between various PBDs compared to regular meat diet and whole-body BMD, body composition, and weight status.

Methods

A cross-sectional study was conducted with adults (n = 240) aged 30-75 years, who habitually followed dietary patterns: vegan, lacto-vegetarian, pesco-vegetarian, semi-vegetarian, or regular meat eater (48 per group). Parameters were measured using dual-energy x-ray absorptiometry (DXA), and multivariable regression analyses were used to adjust for lifestyle confounders, socioeconomic factors, and BMI.

Results

After adjustments, whole-body BMD and body composition were not significantly different between those following PBDs and regular meat diets, except for lacto-ovo vegetarians, who had significantly lower lean mass by -1.46 kg (CI: -2.78, -0.13). Moreover, lacto-ovo vegetarians had a significantly lower T-score by -0.41 SD (CI: -0.81, -0.01) compared to regular meat eaters. Waist circumference was significantly lower in individuals adhering to a PBD compared to a regular meat diet: vegans by -4.67 cm (CI: -8.10, -1.24), lacto-ovo vegetarians by -3.92 cm (CI: -6.60, -1.23), pesco-vegetarians by -3.24 cm (CI: -6.09, -0.39), and semi-vegetarians by -5.18 cm (CI: -7.79, -2.57). There were no significant differences in lean mass (%), fat mass (% and total), android/gynoid measures, body weight, or BMI across dietary patterns. All dietary patterns met the recommended dietary intake for calcium and protein, and 25-hydroxy-vitamin D status was comparable across groups.

Conclusions

This cross-sectional study found that adhering to a PBD characterized by varying degrees of dairy and meat restriction is not associated with meaningful changes in BMD or body composition, provided that the dietary patterns are planned appropriately with adequate levels of calcium and protein.

The potential benefits and mechanisms of protein nutritional intervention on bone health improvement

Osteoporosis commonly occurs in the older people and severe patients, with the main reason of the imbalance of bone metabolism (the rate of bone resorption exceeding the rate of bone formation), resulting in a decrease in bone mineral density and destruction of bone microstructure and further leading to the increased risk of fragility fracture. Recent studies indicate that protein nutritional support is beneficial for attenuating osteoporosis and improving bone health. This review summarized the classical mechanisms of protein intervention for alleviating osteoporosis on both suppressing bone resorption and regulating bone formation related pathways (promoting osteoblasts generation and proliferation, enhancing calcium absorption, and increasing collagen and mineral deposition), as well as the potential novel mechanisms via activating autophagy of osteoblasts, altering bone related miRNA profiles, regulating muscle-bone axis, and modulating gut microbiota abundance. Protein nutritional intervention is expected to provide novel approaches for the prevention and adjuvant therapy of osteoporosis.

Risk of Bone Fracture on Vegetarian and Vegan Diets

PURPOSE OF REVIEW

Bone fractures can have a devastating effect on health, especially in the elderly, undermining their independence for daily activities, and increasing the risk of comorbidities and mortality. Nutrition is a key factor in maintaining an optimal bone health across the lifespan. The number of people that choose to avoid meat or even all animal products is increasing globally, for a diversity of reasons. Properly planned vegetarian and vegan diets are widely recognized as a healthy dietary pattern, but the long-term impact of these diets on bone health and more specifically risk of bone fractures is less clear. Classic studies have observed a slightly lower bone mineral density in vegetarians but have many limitations, including inadequate adjusting for relevant confounding factors, and cross-sectional design. The aim of this review is to summarize and put into context the current evidence on the effect of vegetarian and vegan diets on bone health, with a focus on fracture risk.

RECENT FINDINGS

In recent years, results from many large prospective studies have emerged, which allowed us to assess the risk of incident bone fractures in vegetarians. In these studies, vegetarian and especially vegan diets were associated with an increased risk of bone fractures. In many recent prospective cohort studies, vegetarian and especially vegan diets were associated with an increased risk of bone fractures. At least part of this risk could be due to a lower body mass index and a lower intake of nutrients such as calcium, vitamin D, and protein. Some evidence suggests that combined vitamin D and calcium supplementation and other factors such as consumption of protein-rich foods may attenuate this risk. The eventual deleterious effect of vegetarian diets on bone health should be contextualized and balanced with its benefits, such as lower risk of cardiovascular disease and cancer.

Associations of healthy eating index-2015 with osteoporosis and low bone mass density in postmenopausal women: a population-based study from NHANES 2007-2018

Purpose

The current study aimed to explore the associations of diet quality assessed by healthy eating index-2015 (HEI-2015) with risks of osteoporosis and low bone mineral density (BMD) among American postmenopausal women aged 50 years and older.

Methods

Postmenopausal women aged 50 years and older in the National Health and Nutrition Examination Survey from 2007 through 2018 were included in the final sample. Analysis of variance and Rao-Scott adjusted chi-square tests were used to compare the characteristics across tertiles of HEI-2015. Univariate and multivariate weighted logistic regression models were employed to explore the associations of HEI-2015 tertiles and continuous HEI-2015 with the risks of osteoporosis and low BMD. Nonlinear dose-response associations were evaluated using weighted restricted cubic spline analyses, and the contributions of various HEI-2015 components were assessed using weighted quantile sum regression models.

Results

The final sample included 3,421 postmenopausal women aged 50 years and older representative for approximately 28.38 million non-institutionalized U.S. postmenopausal women. Osteoporosis prevalence decreased with HEI-2015 tertiles while the prevalence of low BMD showed no significant decrease. Compared with postmenopausal women in the first tertile of HEI-2015, those with the second (OR: 0.57, 95%CI: 0.38-0.84) and third (OR: 0.48, 95%CI: 0.29-0.78) HEI-2015 tertiles were associated with reduced osteoporosis risk after multivariate adjustments, but no significant association of HEI-2015 with the risk of BMD was identified. Furthermore, similar effects were confirmed in the sensitivity analyses and subgroup analyses and interaction effects. Moreover, significant nonlinear associations were observed between HEI-2015 with osteoporosis risk, and total vegetables, refined grains and greens and beans demonstrated the strongest protective effect among HEI-2015 components against osteoporosis.

Conclusions

This study strongly suggests the significant negative associations of HEI-2015 with osteoporosis risk in American postmenopausal women. These findings highlight the importance of adherence to the dietary guidelines for Americans in reducing the risk of osteoporosis.

Dietary acid load in health and disease

Maintaining an appropriate acid-base equilibrium is crucial for human health. A primary influencer of this equilibrium is diet, as foods are metabolized into non-volatile acids or bases. Dietary acid load (DAL) is a measure of the acid load derived from diet, taking into account both the potential renal acid load (PRAL) from food components like protein, potassium, phosphorus, calcium, and magnesium, and the organic acids from foods, which are metabolized to bicarbonate and thus have an alkalinizing effect. Current Western diets are characterized by a high DAL, due to large amounts of animal protein and processed foods. A chronic low-grade metabolic acidosis can occur following a Western diet and is associated with increased morbidity and mortality. Nutritional advice focusing on DAL, rather than macronutrients, is gaining rapid attention as it provides a more holistic approach to managing health. However, current evidence for the role of DAL is mainly associative, and underlying mechanisms are poorly understood. This review focusses on the role of DAL in multiple conditions such as obesity, cardiovascular health, impaired kidney function, and cancer.

Examination of Primary and Secondary Metabolites Associated with a Plant-Based Diet and Their Impact on Human Health

The consumption of plant-based diets has become a burgeoning trend, and they are increasingly consumed globally owing to their substantial energy intensity and dietetic advantages. Plants possess numerous bioactive components that have been recognized to exhibit manifold health-promoting assets. Comprehension of the synthesis of these primary and secondary metabolites by plants and their method of action against several chronic illnesses is a significant requirement for understanding their benefits to human health and disease prevention. Furthermore, the association of biologically active complexes with plants, humans, disease, medicine, and the underlying mechanisms is unexplored. Therefore, this review portrays various bioactive components derived from plant sources associated with health-promoting traits and their action mechanisms. This review paper predominantly assembles proposed plant-derived bioactive compounds, postulating valuable evidence aimed at perceiving forthcoming approaches, including the selection of potent bioactive components for formulating functional diets that are effective against several human disorders. This meticulous evidence could perhaps provide the basis for the advanced preemptive and therapeutic potential promoting human health. Hence, delivery opens possibilities for purchasers to approach the lucrative practice of plants as a remedy, produce novel products, and access new marketplaces.

Isoflavone intervention and its impact on bone mineral density in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials

Due to estrogen deficiency, postmenopausal women may suffer from an imbalance in bone metabolism that leads to bone fractures. Isoflavones, a type of phytoestrogen, have been suggested to improve bone metabolism and increase bone mass. Therefore, isoflavones are increasingly recognized as a promising natural alternative to hormone replacement therapy for postmenopausal women who face a heightened risk of osteoporosis and are susceptible to bone fractures.

PURPOSE

This study aimed to evaluate the efficacy of isoflavone interventions on bone mineral density (BMD) in postmenopausal women by means of systematic review and meta-analysis.

METHODS

The electronic database searches were performed on PubMed, Embase, Scopus, and Cochrane Library databases, covering literature up to April 20, 2023. A random-effects model was used to obtain the main effect estimates, with a mean difference (MD) and its 95% confidence interval (CI) as the effect size summary. The risk of bias assessment was conducted using the Risk of Bias 2 (RoB2) tool.

RESULTS

A total of 63 randomized controlled trials comparing isoflavone interventions (n = 4,754) and placebo (n = 4,272) were included. The results indicated that isoflavone interventions significantly improved BMD at the lumbar spine (MD = 0.0175 g/cm2; 95% CI, 0.0088 to 0.0263, P < 0.0001), femoral neck (MD = 0.0172 g/cm2; 95% CI, 0.0046 to 0.0298, P = 0.0073), and distal radius (MD = 0.0138 g/cm2; 95% CI, 0.0077 to 0.0198, P < 0.0001) in postmenopausal women. Subgroup analysis showed that the isoflavone intervention was effective for improving BMD when the duration was ≥ 12 months and when the intervention contained genistein of at least 50 mg/day.

CONCLUSION

This systematic review and meta-analysis suggests that isoflavone interventions, especially those containing genistein of at least 50 mg/day, can effectively enhance BMD in postmenopausal women.

Effects of partial replacement of red and processed meat with non-soya legumes on bone and mineral metabolism and amino acid intakes in BeanMan randomised clinical trial

The transition towards more plant-based diets may pose risks for bone health such as low vitamin D and Ca intakes. Findings for the contribution of animal and plant proteins and their amino acids (AA) to bone health are contradictory. This 6-week clinical trial aimed to investigate whether partial replacement of red and processed meat (RPM) with non-soya legumes affects AA intakes and bone turnover and mineral metabolism in 102 healthy 20-65-year-old men. Participants were randomly assigned to diet groups controlled for RPM and legume intake (designed total protein intake (TPI) 18 E%): the meat group consumed 760 g RPM per week (25 % TPI) and the legume group consumed non-soya legume-based products (20 % TPI) and 200 g RPM per week, the upper limit of the Planetary Health Diet (5 % TPI). No differences in bone (bone-specific alkaline phosphatase; tartrate-resistant acid phosphatase 5b) or mineral metabolism (25-hydroxyvitamin D; parathyroid hormone; fibroblast growth factor 23; phosphate and Ca) markers or Ca and vitamin D intakes were observed between the groups (P > 0·05). Methionine and histidine intakes were higher in the meat group (P ≤ 0·042), whereas the legume group had higher intakes of arginine, asparagine and phenylalanine (P ≤ 0·013). Mean essential AA intakes in both groups met the requirements. Increasing the proportion of non-soya legumes by reducing the amount of RPM in the diet for 6 weeks did not compromise bone turnover and provided on average adequate amounts of AA in healthy men, indicating that this ecologically sustainable dietary change is safe and relatively easy to implement.

Nutritional strategies to optimise musculoskeletal health for fall and fracture prevention: Looking beyond calcium, vitamin D and protein

Falls and osteoporotic fractures are a major public health problem, particularly among older adults. A third of individuals aged 65 years and over fall at least once each year, with up to 20 % of these resulting in serious injury, including fracture. In conjunction with regular exercise, the importance of diet for musculoskeletal health has largely focused upon calcium, vitamin D, and protein, particularly in the context of preventing falls and fractures. Whilst there is evidence for the benefits of these nutrients for musculoskeletal health, other aspects of the diet remain largely underexplored. For example, vegetables are rich sources of macro- and micronutrients that are essential for muscle function and bone health, which are key factors in the prevention of falls and fractures. Recent work has highlighted the importance of nutrients such as vegetable-derived nitrate and vitamin K1 in optimising muscle strength, physical function, and bone quality. In the context of dietary patterns, vegan/plant-based diets have recently gained popularity due to perceived health benefits, animal welfare, or to tackle climate change. The elimination and/or substitution of animal-based products for plant foods (without careful planning and/or expert dietary guidance) could, however, have long-term negative musculoskeletal consequences; a trend uncovered by recent evidence. Within the overarching theme of nutrition for fall and fracture prevention in older populations, the aim of this review is to (i) summarise the current evidence for calcium, vitamin D and protein; (ii) describe the importance of vegetables and selected nutrients, such as nitrate and vitamin K1, for muscle function and bone structural integrity; and (iii) highlight current evidence around different dietary patterns (e.g., plant-based, diet quality, data driven approaches) and their impact on musculoskeletal health.

The skeletal safety of milk-derived proteins: A meta-analysis of randomized controlled trials

PURPOSE

There has been a persistent claim that dairy products contain calcium-leaching proteins, although the soundness of such a claim has been challenged. A meta-analysis of randomized controlled trials (RCTs) on the effects of milk-derived protein supplementation on bone health indices in adults was performed to reconcile the controversy surrounding the potential skeletal safety concerns of proteins of dairy origin.

METHODS

The PubMed and Web of Science databases were searched for relevant RCTs. A random-effects model was used to generate pooled effect sizes and 95% confidence intervals.

RESULTS

Milk-derived protein supplementation did not significantly affect whole-body BMD (n = 7 RCTs) and BMD at the lumbar spine (n = 10), hip (n = 8), femoral neck (n = 9), trochanter (n = 5), intertrochanter (n = 2), and ultradistal radius (n = 2). The concentrations of bone formation markers (bone-specific alkaline phosphatase [n = 11], osteocalcin [n = 6], procollagen type 1 amino-terminal propeptide [n = 5]), bone resorption markers (N-terminal telopeptide of type 1 collagen [n = 7], C-terminal telopeptide of type 1 collagen [n = 7], deoxypyridinoline [n = 4]), and parathyroid hormone (n = 7) were not significantly affected. However, increased insulin-like growth factor-1 (IGF-1) concentrations (n = 13) were observed. Reduced IGF-1 concentrations were observed when soy protein was used as a comparator, and increased IGF-1 concentrations were observed when carbohydrate was used.

CONCLUSION

Our findings do not support the claim that proteins of dairy origin are detrimental to bone health.

Impact of Dietary Protein on Osteoporosis Development

Osteoporosis is a frequent yet unsolved health problem among older people. The influence of dietary protein still raises many questions regarding its quality and quantity in the context of bone health. The aim of this manuscript is to review the latest evidence on plant and animal protein influences on bone health in various groups of patients. The review is based on original studies, meta-analyses, randomized controlled trials, and prospective cohort studies published in PubMed and Cochrane databases during the last five years. Combining plant and animal protein with physical activity has the best effect on bones (muscle strengthening and reducing the risk of falls), while high protein intake can have adverse effects during bed rest. Despite the content of isoflavones, plant protein is not more beneficial than animal protein (dairy products) and can increase bone resorption markers. Hypoestrogenism due to menopause or eating disorders leads to low bone density and an increased risk of osteoporosis. A well-balanced diet with sufficient energy supply and protein intake (both of plant and animal origins) and adequate physical activity are crucial to ensure bone health. Dietary interventions should consider the quantity and quality of protein in patients with other comorbidities, particularly in an aging society.

The Influences of Macronutrients on Bone Mineral Density, Bone Turnover Markers, and Fracture Risk in Elderly People: A Review of Human Studies

Osteoporosis is a health condition that involves weak bone mass and a deteriorated microstructure, which consequently lead to an increased risk of bone fractures with age. In elderly people, a fracture attributable to osteoporosis elevates mortality. The objective of this review was to examine the effects of macronutrients on bone mineral density (BMD), bone turnover markers (BTMs), and bone fracture in elderly people based on human studies. A systematic search was conducted in the PubMed®/MEDLINE® database. We included human studies published up to April 2023 that investigated the association between macronutrient intake and bone health outcomes. A total of 11 meta-analyses and 127 individual human studies were included after screening the records. Carbohydrate consumption seemed to have neutral effects on bone fracture in limited studies, but human studies on carbohydrates' effects on BMD or/and BTMs are needed. The human studies analyzed herein did not clearly show whether the intake of animal, vegetable, soy, or milk basic proteins has beneficial effects on bone health due to inconsistent results. Moreover, several individual human studies indicated an association between eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and osteocalcin. Further studies are required to draw a clear association between macronutrients and bone health in elderly people.

Effects of Plant-Based Protein Interventions, with and without an Exercise Component, on Body Composition, Strength and Physical Function in Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Maintaining muscle mass, strength, and function is crucial for our aging population. Exercise and dietary protein intake are recommended strategies; however, animal proteins have been the most studied. Plant-based protein sources have lower digestibility and incomplete amino acid profiles. However new innovative plant-based proteins and products may have overcome these issues. Therefore, this systematic review aimed to synthesize the current research and evaluate the effects of plant-based protein interventions compared to placebo on body composition, strength, and physical function in older adults (≥60 years old). The secondary aim was whether exercise improved the effectiveness of plant-based protein on these outcomes. Randomized controlled trials up to January 2023 were identified through Medline, EMBASE, CINAHL, and Cochrane Library databases. Studies contained a plant-protein intervention, and assessed body composition, strength, and/or physical function. Thirteen articles were included, all using soy protein (0.6-60 g daily), from 12 weeks to 1 year. Narrative summary reported positive effects on muscle mass over time, with no significant differences compared to controls (no intervention, exercise only, animal protein, or exercise + animal protein interventions). There was limited impact on strength and function. Meta-analysis showed that plant-protein interventions were comparable to controls, in all outcomes. In conclusion, plant-protein interventions improved muscle mass over time, and were comparable to other interventions, warranting further investigation as an anabolic stimulus in this vulnerable population.

Dairy and Plant-Based Milks: Implications for Nutrition and Planetary Health

PURPOSE OF REVIEW

Dairy milk products are dominant in the market; however, plant-based milks are gaining prominence among USA consumers. Many questions remain about how plant-based milk products compare to dairy milk from a nutrition, public health, and planetary health perspective. Here, we compare the retail sales, nutrient profiles, and known health and environmental impacts of the production and consumption of dairy and plant-based milks and identify knowledge gaps for future studies. For our plant-based milk comparisons, we reviewed almond, soy, oat, coconut, rice, pea, cashew, and other plant-based milks as data were available.

RECENT FINDINGS

The retail unit price of plant-based milks was generally higher than that of cow's milk, making it less accessible to lower-income groups. Many plant-based milks are fortified to match the micronutrient profile of dairy milk more closely. Notable differences remained, especially in protein, zinc, and potassium, depending on the base ingredient and individual product. Some plant-based milks contain added sugar to improve flavor. Plant-based milks were generally associated with lower environmental impacts (e.g., greenhouse gas emissions, water use) than cow's milk, with the notable exception of the higher water footprint of almond milk. This review of recent studies and consumer purchases confirmed that retail sales of plant-based milks are increasing and shifting among products. Further research is needed to better characterize the environmental impacts of newer plant-based milks, such as cashew, hemp, and pea milks; consumer attitudes and behavior towards plant-based milks; and the safety and potential health effects related to their long-term and more frequent consumption.

Consumption Patterns and the Nutritional Contribution of Total, Processed, Fresh, and Fresh-Lean Pork to the U.S. Diet

Pork has the potential to provide several macro and micronutrients to the diet, as it is a commonly consumed protein in the United States and across many cultures worldwide. There is an absence of clinical and observational studies that isolate the nutritional contribution of various types of pork intake from that of other red and/or processed meats. The objective of this study was to assess consumption patterns and the nutritional contribution of total, processed, fresh, and fresh-lean pork to the diets of participants aged 2+ years enrolled in the National Health and Nutrition Examination Survey (NHANES) 2007-2018 data cycles. The recent National Cancer Institute method was used to disaggregate fresh and processed pork intake from the USDA Food Patterns Equivalents Database. The mean intake of total pork among consumers was estimated to be 79.5 ± 0.82, 54.2 ± 0.69, 54.6 ± 0.93, and 45.9 ± 0.73, g/d for men, women, boys, and girls, respectively. Total pork consumption subtly increased intakes of total energy and several macro and micronutrients, decreased diet quality (HEI-2015) scores (adults only), and consumption of other "healthful" food groups. Only subtle but clinically insignificant effects of pork intake on biomarkers of nutritional status were shown. These trends were largely driven by processed pork consumption and the co-consumption of foods such as condiments. Increasing the availability and education around fresh-lean cuts may help to increase intake of protein and other key nutrients across certain subpopulations, without adversely affecting diet quality and biomarkers of health status.

Protein intake and bone health: an umbrella review of systematic reviews for the evidence-based guideline of the German Nutrition Society

This umbrella review aimed at assessing whether a protein intake exceeding the current recommendation for younger (0.8 g/kg body weight [BW]/day) and older (1.0 g/kg BW/day) adults affects bone mineral density and fracture risk. Moreover, the effect of animal or plant protein was evaluated. A systematic literature search was conducted in PubMed, Embase, and Cochrane Database of Systematic Reviews for systematic reviews (SRs) with or without meta-analysis of prospective studies published between 11/2008 and 08/2021. Methodological quality, outcome-specific certainty of evidence, and overall certainty of evidence of the retrieved SRs were assessed using established tools and predefined criteria. Eleven SRs of randomized controlled trials (RCTs) and/or cohort studies were included. In SRs of cohort studies and RCTs, protein intake/kg BW/day ranged between 0.21-0.95 g (low intake) and > 1.24 g (high intake), respectively, and between 0.67-1.1 g (control groups) and 1.01-1.69 g (intervention groups), respectively. The vast majority of outcome-specific certainty of evidence was rated "low" or "very low." The overall certainty of evidence for an association (cohort studies) or effect (RCTs) of total, animal or plant protein intake on each of the investigated outcomes was rated "insufficient," with the exception of possible evidence for a reduced hip fracture risk by high vs. low protein intake. Since protein intakes in low/control and high/intervention groups were very heterogeneous and with low certainty of evidence, it remains unclear whether a dose above the current recommendation or type of protein intake (animal or plant protein) affects bone health overall. However, there is possible evidence for reduced hip fracture risk with high versus low protein intake.

Increased Dietary Intakes of Total Protein, Animal Protein and White Meat Protein Were Associated with Reduced Bone Loss—A Prospective Analysis Based on Guangzhou Health and Nutrition Cohort, South China

In this study, we aimed to prospectively investigate the relationships between different types of dietary protein and changes in bone mass in Chinese middle-aged and elderly people. Dietary intakes were evaluated by means of a validated food frequency questionnaire. Bone mineral density (BMD) was measured using a dual-energy bone densitometer at multiple bone sites. Multivariable regression models were applied to investigate the associations of the participants’ dietary intakes of total protein, intakes of protein from various sources, and amino acid intakes with the annualized changes in BMD during a 3-year follow-up. A total of 1987 participants aged 60.3 ± 4.9 years were included in the analyses. Multivariable linear regression results showed that dietary intakes of total protein, animal protein, and protein from white meat were positively correlated with BMD changes, with standardized coefficients (β) of 0.104, 0.073, and 0.074 at the femur neck (p < 0.01) and 0.118, 0.067, and 0.067 at the trochanter (p < 0.01), respectively. With each increase of 0.1g·kg−1·d−1 in animal protein and white meat protein intakes, the BMD losses were reduced by 5.40 and 9.24 mg/cm2 at the femur neck (p < 0.05) and 1.11 and 1.84 mg/cm2 at the trochanter (p < 0.01), respectively. Our prospective data, obtained from Chinese adults, showed that dietary total and animal protein, especially protein from white meat, could significantly reduce bone loss at the femur neck and trochanter.

Nutritional Assessment of the Symptomatic Patient on a Plant-Based Diet: Seven Key Questions

Plant-based diets, both vegan and vegetarian, which emphasize grains, vegetables, fruits, legumes, nuts, and seeds are increasingly popular for health as well as financial, ethical, and religious reasons. The medical literature clearly demonstrates that whole food plant-based diets can be both nutritionally sufficient and medically beneficial. However, any person on an intentionally restrictive, but poorly-designed diet may predispose themselves to clinically-relevant nutritional deficiencies. For persons on a poorly-designed plant-based diet, deficiencies are possible in both macronutrients (protein, essential fatty acids) and micronutrients (vitamin B12, iron, calcium, zinc, and vitamin D). Practitioner evaluation of symptomatic patients on a plant-based diet requires special consideration of seven key nutrient concerns for plant-based diets. This article translates these concerns into seven practical questions that all practitioners can introduce into their patient assessments and clinical reasoning. Ideally, persons on plant-based diets should be able to answer these seven questions. Each serves as a heuristic prompt for both clinician and patient attentiveness to a complete diet. As such, these seven questions support increased patient nutrition knowledge and practitioner capacity to counsel, refer, and appropriately focus clinical resources.

Healthy plant-based diet index as a determinant of bone mineral density in osteoporotic postmenopausal women: A case-control study

Introduction

The association between plant-based diet indices and bone mineral density (BMD) of women with osteoporosis have not been studied in Iranian women. This study aimed to evaluate the association between plant-based diet indices and BMD in postmenopausal women with osteopenia/osteoporosis.

Materials and methods

The present research was a case-control study conducted on 131 postmenopausal women with osteoporosis/osteopenia and 131 healthy women. The BMD of the femoral neck and lumbar vertebrae was measured by the Dual-energy X-ray absorptiometry (DXEA) method. Participants were asked to complete a validated semi-quantitative food frequency questionnaire (FFQ). We used three versions of plant-based diet indices, including plant-based diet index (PDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI). Two different multivariable logistic regression was used for the crude and adjusted model to assess the relationship between PDI, hPDI, and uPDI with odds of femoral and lumbar BMD.

Results

There was a reverse association between last tertile of hPDI with femoral BMD abnormality in the both adjusted model [Model 1: odds ratio (OR): 0.33; 95% confidence interval (CI): 0.19-0.63 and Model 2: OR: 0.30; 95% CI: 0.15-0.58, respectively]. Furthermore, we found a reverse relationship between hPDI with lumbar BMD abnormality in the first adjusted model (OR: 0.36; 95% CI: 0.19-0.67). On the other hand, a negative association was observed in the second and last tertile of hPDI with lumbar BMD abnormality (OR: 0.47; 95% CI: 0.24-0.90 and OR: 0.34; 95% CI: 0.17-0.64, respectively). According to the results, the association of femoral BMD abnormality in the last tertile of uPDI compared to the first tertile in the both adjusted models (Model 1: OR: 2.85; 95% CI: 1.52-5.36 and Model 2: OR: 2.63; 95% CI: 1.37-5.06) were significant. Also, we observed a positive relationship between the last tertile of uPDI with lumbar BMD abnormality compared to the lowest tertile in the both adjusted models (Model 1; OR: 4.16; 95% CI: 2.20-7.85, Model 2; OR: 4.23; 95% CI: 2.19-8.19).

Conclusion

Overall, the findings indicated that in postmenopausal women with osteoporosis, a healthy plant-based diet could prevent bone loss, and an unhealthy plant-based diet might have detrimental effects on BMD.

Dietary recommendations in the prevention and treatment of osteoporosis

INTRODUCTION

This article presents the initial recommendations of the French Rheumatology Society (Société Française de Rhumatologie - SFR) and the Osteoporosis Research and Information Group (Groupe de Recherche et d'Informations sur les Ostéoporoses - GRIO) on the role of diet in the prevention and treatment of osteoporosis.

METHODS

The recommendations were produced by a working group composed of rheumatologists, physician nutrition specialists and a geriatrician. Fifteen (15) questions pertaining to "daily practices" were preselected by the working group. For the literature review, the working group focussed mainly on the effects of diet on bone mineral density (BMD) and fractures, and primarily on meta-analyses of longitudinal studies and dietary intervention studies.

RESULTS

A Mediterranean-type diet and the daily consumption of 2 to 3 dairy products are recommended. Together, these provide the calcium and "high quality" protein required to maintain a normal calcium-phosphorus balance and bone metabolism, and are associated with lower fracture risk. Conversely, unbalanced Western diets, vegan diets, weight-loss diets in non-overweight individuals, alcohol consumption and daily consumption of sodas are advised against. In terms of the beneficial effects on bone mineral density and fracture risk, current scientific data are either insufficient or too divergent to recommend increasing or restricting the consumption of tea or coffee, vitamins other than vitamin D, vitamin D-enriched or phytoestrogen-rich foods, calcium-enriched plant-based beverages, oral nutritional supplements, or dietary sources of prebiotics and probiotics.

CONCLUSIONS

These are the first set of recommendations addressing the role of diet in the prevention and treatment of osteoporosis. More research is necessary to direct and support guidelines.

Vegan nutrition: a preliminary guide for health professionals

Since the beginning of the 21st century, interest in vegan diets has been rapidly increasing in most countries. Misconceptions about vegan diets are widespread among the general population and health professionals. Vegan diets can be health-promoting and may offer certain important advantages compared to typical Western (and other mainstream) eating patterns. However, adequate dietary sources/supplements of nutrients of focus specific to vegan diets should be identified and communicated. Without supplements/fortified foods, severe vitamin B12 deficiency may occur. Other potential nutrients of focus are calcium, vitamin D, iodine, omega-3 fatty acids, iron, zinc, selenium, vitamin A, and protein. Ensuring adequate nutrient status is particularly important during pregnancy, lactation, infancy, and childhood. Health professionals are often expected to be able to provide advice on the topic of vegan nutrition, but a precise and practical vegan nutrition guide for health professionals is lacking. Consequently, it is important and urgent to provide such a set of dietary recommendations. It is the aim of this article to provide vegan nutrition guidelines, based on current evidence, which can easily be communicated to vegan patients/clients, with the goal of ensuring adequate nutrient status in vegans.

The health effects of soy: A reference guide for health professionals

Soy is a hotly debated and widely discussed topic in the field of nutrition. However, health practitioners may be ill-equipped to counsel clients and patients about the use of soyfoods because of the enormous, and often contradictory, amount of research that has been published over the past 30 years. As interest in plant-based diets increases, there will be increased pressure for practitioners to gain a working knowledge of this area. The purpose of this review is to provide concise literature summaries (400-500 words) along with a short perspective on the current state of knowledge of a wide range of topics related to soy, from the cholesterol-lowering effects of soy protein to the impact of isoflavones on breast cancer risk. In addition to the literature summaries, general background information on soyfoods, soy protein, and isoflavones is provided. This analysis can serve as a tool for health professionals to be used when discussing soyfoods with their clients and patients.

Association between macronutrients intake distribution and bone mineral density

BACKGROUND & AIMS

Although it is well known dietary factors are closely correlated with bone health, the association between macronutrients intake distribution and bone mineral density (BMD) is still unclear. The aims of this study were to investigate how macronutrients distribution was correlated with BMD, and to evaluate how the substitution between macronutrients could be associated with BMD.

METHODS

We conducted a cross-sectional study based on data from National Health and Nutrition Examination Survey. Dietary recall method was used to assessed the intake of macronutrients. Macronutrient intake distribution including carbohydrate, protein and fat was calculated as percentages of energy intake from total energy. BMD was converted to T-score and low BMD was defined as T-score less than -1.0. The association between the percentages of energy intake from carbohydrate, protein and fat with T-score and risk of low BMD was evaluated using multivariate regression models. Isocaloric substitution analysis was conducted using the multivariate nutrient density method.

RESULTS

Data form 4447 adults aged 20 years and older who underwent BMD examination were included in this study. Higher percentage of energy intake from carbohydrate was associated with lower T-score (-0.03 [95%CI, -0.05 to -0.01]; P = 0.001) and higher risk of low BMD (1.05 [95%CI, 1.02-1.08]; P = 0.003), while higher percentage of energy intake from protein was associated with higher T-score (0.05 [95%CI, 0.01-0.08]; P = 0.009) and lower odds of low BMD (0.92 [95%CI, 0.87-0.98]; P = 0.007). The percentage of energy intake from fat seemed to be positively correlated with T-score, but the correlation became insignificant after adjusting for metabolism related confounders. Isocaloric substitution analysis showed that only the substitution between carbohydrate and protein was significantly and independently associated with T-score (-0.05 [95%CI, -0.08 to -0.01]; P = 0.01) and the risk of low BMD (1.08 [95%CI, 1.02-1.15]; P = 0.008).

CONCLUSIONS

Based on the results from this study, we hypothesized that a high-protein diet coupled with low carbohydrate intake would be beneficiary for prevention of bone loss in adults. However, randomized clinical trials or longitudinal studies are needed to further assessed our findings.

A Review on the Molecular Mechanisms of Action of Natural Products in Preventing Bone Diseases

The drugs used for treating bone diseases (BDs), at present, elicit hazardous side effects that include certain types of cancers and strokes, hence the ongoing quest for the discovery of alternatives with little or no side effects. Natural products (NPs), mainly of plant origin, have shown compelling promise in the treatments of BDs, with little or no side effects. However, the paucity in knowledge of the mechanisms behind their activities on bone remodeling has remained a hindrance to NPs’ adoption. This review discusses the pathological development of some BDs, the NP-targeted components, and the actions exerted on bone remodeling signaling pathways (e.g., Receptor Activator of Nuclear Factor κ B-ligand (RANKL)/monocyte/macrophage colony-stimulating factor (M-CSF)/osteoprotegerin (OPG), mitogen-activated protein kinase (MAPK)s/c-Jun N-terminal kinase (JNK)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), Kelch-like ECH-associated protein 1 (Keap-1)/nuclear factor erythroid 2–related factor 2 (Nrf2)/Heme Oxygenase-1 (HO-1), Bone Morphogenetic Protein 2 (BMP2)-Wnt/β-catenin, PhosphatidylInositol 3-Kinase (PI3K)/protein kinase B (Akt)/Glycogen Synthase Kinase 3 Beta (GSK3β), and other signaling pathways). Although majority of the studies on the osteoprotective properties of NPs against BDs were conducted ex vivo and mostly on animals, the use of NPs for treating human BDs and the prospects for future development remain promising.

The Role of Macronutrients, Micronutrients and Flavonoid Polyphenols in the Prevention and Treatment of Osteoporosis

Osteoporosis is considered an age-related disorder of the skeletal system, characterized primarily by decreased bone mineral density (BMD), microstructural quality and an elevated risk of fragility fractures. This silent disease is increasingly becoming a global epidemic due to an aging population and longer life expectancy. It is known that nutrition and physical activity play an important role in skeletal health, both in achieving the highest BMD and in maintaining bone health. In this review, the role of macronutrients (proteins, lipids, carbohydrates), micronutrients (minerals—calcium, phosphorus, magnesium, as well as vitamins—D, C, K) and flavonoid polyphenols (quercetin, rutin, luteolin, kaempferol, naringin) which appear to be essential for the prevention and treatment of osteoporosis, are characterized. Moreover, the importance of various naturally available nutrients, whether in the diet or in food supplements, is emphasized. In addition to pharmacotherapy, the basis of osteoporosis prevention is a healthy diet rich mainly in fruits, vegetables, seafood and fish oil supplements, specific dairy products, containing a sufficient amount of all aforementioned nutritional substances along with regular physical activity. The effect of diet alone in this context may depend on an individual’s genotype, gene-diet interactions or the composition and function of the gut microbiota.

Life Cycle Environmental Impacts and Health Effects of Protein-Rich Food as Meat Alternatives: A Review

The food sector is responsible for a considerable impact on the environment in most environmental contexts: the food supply chain causes greenhouse gas emissions, water consumption, reduction in cultivable land, and other environmental impacts. Thus, a change in food supply is required to reduce the environmental impacts caused by the food supply chain and to meet the increasing demand for sufficient and qualitative nutrition. Large herds of livestock are inappropriate to achieve these goals due to the relevant impact of meat supply chain on the environment, e.g., the land used to grow feed for animals is eight times more than that for human nutrition. The search for meat alternatives, especially for the intake of critical nutrients such as protein, is a consequent step. In the above context, this paper summarizes the health aspects of protein-rich food alternatives to meat and carries out a literature review on the life-cycle environmental impacts of this alternative food.

The effects of vegetarian diets on bone health: A literature review

In these recent years many people are adopting a vegetarian type diet due to the numerous positive health effects of this regimen such as the reduction of the incidence of many chronic disorders like diabetes, hypertension, obesity and cancer. However this diet is quite restrictive and so it could be possible to have a deficiency in some specific nutrients, increasing the risk of osteoporosis and fractures. Although there are conflicting results on the effects of the vegetarian diet on bone health and fracture incidence, it is always recommendable in vegetarian people to have an adequate intake of calcium and vitamin D, through an increased intake of supplements, natural and fortified foods, an adequate intake of protein, fruit, vegetables, as well as vitamin B12. The aim of this literature review is to revise the actual knowledge of the effect of some nutrients and vegetarian diets on bone health.

Nutritional Considerations for Injury Prevention and Recovery in Combat Sports

Sports participation is not without risk, and most athletes incur at least one injury throughout their careers. Combat sports are popular all around the world, and about one-third of their injuries result in more than 7 days of absence from competition or training. The most frequently injured body regions are the head and neck, followed by the upper and lower limbs, while the most common tissue types injured are superficial tissues and skin, followed by ligaments and joint capsules. Nutrition has significant implications for injury prevention and enhancement of the recovery process due to its effect on the overall physical and psychological well-being of the athlete and improving tissue healing. In particular, amino acid and protein intake, antioxidants, creatine, and omega-3 are given special attention due to their therapeutic roles in preventing muscle loss and anabolic resistance as well as promoting injury healing. The purpose of this review is to present the roles of various nutritional strategies in reducing the risk of injury and improving the treatment and rehabilitation process in combat sports. In this respect, nutritional considerations for muscle, joint, and bone injuries as well as sports-related concussions are presented. The injury risk associated with rapid weight loss is also discussed. Finally, preoperative nutrition and nutritional considerations for returning to a sport after rehabilitation are addressed.

The Safe and Effective Use of Plant-Based Diets with Guidelines for Health Professionals

Plant-based diets, defined here as including both vegan and lacto-ovo-vegetarian diets, are growing in popularity throughout the Western world for various reasons, including concerns for human health and the health of the planet. Plant-based diets are more environmentally sustainable than meat-based diets and have a reduced environmental impact, including producing lower levels of greenhouse gas emissions. Dietary guidelines are normally formulated to enhance the health of society, reduce the risk of chronic diseases, and prevent nutritional deficiencies. We reviewed the scientific data on plant-based diets to summarize their preventative and therapeutic role in cardiovascular disease, cancer, diabetes, obesity, and osteoporosis. Consuming plant-based diets is safe and effective for all stages of the life cycle, from pregnancy and lactation, to childhood, to old age. Plant-based diets, which are high in fiber and polyphenolics, are also associated with a diverse gut microbiota, producing metabolites that have anti-inflammatory functions that may help manage disease processes. Concerns about the adequate intake of a number of nutrients, including vitamin B12, calcium, vitamin D, iron, zinc, and omega-3 fats, are discussed. The use of fortified foods and/or supplements as well as appropriate food choices are outlined for each nutrient. Finally, guidelines are suggested for health professionals working with clients consuming plant-based diets.

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

BACKGROUND

Dietary recommendations may underestimate the protein older adults need for optimal bone health. This study sought to determine associations of protein intake with bone mineral density (BMD) and fracture among community-dwelling White and Black older adults.

METHOD

Protein as a percentage of total energy intake (TEI) was assessed with a Food Frequency Questionnaire in 2160 older adults (73.5 ± 2.8 years; 51.5% women; 35.8% Black) in the Health, Aging, and Body Composition prospective cohort. Hip, femoral neck, and whole body BMD was assessed by dual-energy x-ray absorptiometry at baseline and 4 years, and lumbar trabecular, cortical, and integral BMD was assessed by computed tomography at baseline and 5 years. Fragility fractures over 5 years were adjudicated from self-report data collected every 6 months. Associations with tertiles of protein intake were assessed using analysis of covariance for BMD and multivariate Cox regression for fracture, adjusting for confounders.

RESULTS

Participants in the upper protein tertile (≥15% TEI) had 1.8%-6.0% higher mean hip and lumbar spine BMD compared to the lower protein tertile (<13% TEI; p < .05). Protein intake did not affect change in BMD at any site over the follow-up period. Participants in the upper protein tertile had a reduced risk of clinical vertebral fracture over 5 years of follow-up (hazard ratio: 0.36 [95% confidence interval: 0.14, 0.97] vs lower protein tertile, p = .04).

CONCLUSIONS

Older adults with higher protein intake (≥15% TEI) had higher BMD at the hip, whole body, and lumbar spine, and a lower risk of vertebral fracture.

A 1:1 matched case-control study on dietary protein intakes and hip fracture risk in Chinese elderly men and women

The role of protein intake in bone has been controversial. Our case-control study among Chinese elderly concluded that a higher consumption of protein, even substituted for fat, is associated with lowered hip fracture risk. Differences in protein sources, amino acids composition, gender, and calcium sufficiency may explain the inconsistency.

PURPOSE

The aim of the study was to investigate the association of dietary protein intakes with hip fracture risk among Chinese elderly.

METHODS

This was a 1:1 age and sex matched cross-sectional study of case-control design among 1070 pairs of elderly Chinese people aged 55 to 80 years. Patients who were newly diagnosed (within 2-week) hip fracture by X-ray were recruited from four hospitals in Guangdong Province of China. Dietary intakes were evaluated by a validated food frequency questionnaire for total protein, protein from different sources, amino acids profiles, and estimated renal acid load in diet.

RESULTS

Daily average intakes of total protein were 58.1±27.0 (women) and 65.7±31.8 (men) g/d for cases, and 66.8±21.5 (women) and 72.1±24.4 (men) for controls (p<0.001). Multivariable regression indicated that, compared with the lowest quartile, the highest quartile of consumption of energy adjusted total protein [OR: 0.360 (0.206~0.630) for women and 0.381 (0.153~0.949) for men] and animal protein [0.326 (0.183, 0.560) for women and 0.335 (0.136~0.828) for men] was significantly associated with the lowered risk of hip fracture in a dose-response manner (all p for trend <0.05). A significant hip fracture risk reduction was observed in women with higher intakes of sulfur amino acids [OR: 0.464 (0.286~0.753)] and aromatic amino acids [0.537 (0.326~0.884)] but not in men. Subgroup analysis suggested that these associations were more evident in elderly with lower body mass index and dietary calcium intake less than 400 mg/d.

CONCLUSIONS

A higher level of protein intake, even substituted for fat, is associated with lowered hip fracture risk.

Nutrients with anabolic/anticatabolic, antioxidant, and anti-inflammatory properties: Targeting the biological mechanisms of aging to support musculoskeletal health

Old age is associated with declines in bone density and muscle mass and function, which predisposes to mobility disability, falls, and fractures. Poor nutritional status, a risk factor for several age-related pathologies, becomes prevalent in old age and contributes to the structural and functional changes of the musculoskeletal system that increases the risk of osteoporosis, sarcopenia, osteosarcopenia, and physical frailty. The biological mechanisms underpinning these pathologies often overlap and include loss of proteostasis, impaired redox functioning, and chronic low-grade inflammation. Thus, provision of nutrients with anabolic/anticatabolic, antioxidant, and anti-inflammatory properties may be an effective strategy to offset these age-related pathologies. We searched PUBMED for pre-clinical and clinical work examining the effects of nutrients with a combined effect on muscle and bone. This review summarizes recent evidence on the mechanisms of action and potential clinical use of nutrients that concomitantly improve muscle and bone health in older persons.

Role of diet in osteoporosis incidence: Umbrella review of meta-analyses of prospective observational studies

An umbrella review and meta-analysis were conducted to summarize evidence for the association between dietary factors and the incidence of osteoporosis in adults. Only systematic reviews or meta-analyses were eligible for this study. Two researchers independently performed reading, data extraction, and quality evaluation of the included literature. The outcomes included in this study were all associated with osteoporosis, including osteoporotic fractures and low bone density. A total of 54 studies were included in this study, with 83 adjusted hazard ratios on diet, dairy group (n = 13), alcohol (n = 2), tea (n = 6), coffee (n = 3), micronutrient (n = 31), dietary pattern (n = 21), and foods (n = 7) regarding the incidence of osteoporosis. Grades of Recommendations, Assessment, Development, and Evaluation (GRADE) quality assessment method was used in this study. The high, medium, low and very low quality studies accounted for 27.7, 41, 21.7 and 9.6% of this study, respectively. Based on the included literature studies in this umbrella review, it was found that dietary factors have a relevant impact on the incidences of human osteoporosis, appropriate consumption of dairy products, vegetables, fruits, and micronutrients, as well as reduced intake of alcohol and coffee, can reduce the risk of osteoporosis.

Diet Quality and Bone Density in Youth with Healthy Weight, Obesity, and Type 2 Diabetes

PURPOSE

To assess relationships between diet quality and areal bone mineral density (aBMD) in youth with healthy weight, obesity, and type 2 diabetes (T2D).

METHODS

We performed a secondary analysis of cross-sectional data from youth (55% African American, 70% female) ages 10-23 years with T2D (n = 90), obesity (BMI > 95th; n = 128), or healthy weight (BMI < 85th; n = 197). Whole body (less head) areal bone mineral density (aBMD) was assessed by dual-energy X-ray absorptiometry (DXA). aBMD was expressed as age-, sex-, and ancestry-specific standard deviation scores (Z-scores). Whole body aBMD Z-scores were adjusted for height-for-age Z-score. Diet was assessed via three-day diaries, and the Healthy Eating Index (HEI) was computed. Total HEI score and HEI subcomponent scores were compared across groups, and associations with aBMD Z-scores were assessed via linear regression adjusted for group, age, sex, and ancestry.

RESULTS

Mean HEI was similar between the healthy weight, obesity, and T2D groups. Several HEI sub-components differed between groups, including meats and beans, total vegetables, milk, saturated fat, sodium, oils, and empty calories. The obesity and T2D group had significantly greater aBMD Z-scores compared to the healthy weight group. Multiple linear regression analyses revealed a significant positive association between HEI and aBMD Z-score (p < 0.05). The HEI sub-components for whole grains (p = 0.052) and empty calories (p < 0.05) were positively associated with aBMD Z-score.

CONCLUSIONS

Individuals that followed a dietary pattern more closely aligned with the Dietary Guidelines for Americans had greater bone density. Since few studies have investigated the role of diet on bone in youth with obesity-related conditions, additional research is required among these populations.

Bone Quality in Chronic Kidney Disease Patients: Current Concepts and Future Directions - Part II

Background

Patients with chronic kidney disease (CKD) have an increased risk of osteoporotic fractures, which is due not only to low bone volume and mass but also poor microarchitecture and tissue quality. The pharmacological and nonpharmacological interventions detailed, herein, are potential approaches to improve bone health in CKD patients. Various medications build up bone mass but also affect bone tissue quality. Antiresorptive therapies strikingly reduce bone turnover; however, they can impair bone mineralization and negatively affect the ability to repair bone microdamage and cause an increase in bone brittleness. On the other hand, some osteoporosis therapies may cause a redistribution of bone structure that may improve bone strength without noticeable effect on BMD. This may explain why some drugs can affect fracture risk disproportionately to changes in BMD.

Summary

An accurate detection of the underlying bone abnormalities in CKD patients, including bone quantity and quality abnormalities, helps in institution of appropriate management strategies. Here in this part II, we are focusing on advancements in bone therapeutics that are anticipated to improve bone health and decrease mortality in CKD patients.

Key Messages

Therapeutic interventions to improve bone health can potentially advance life span. Emphasis should be given to the impact of various therapeutic interventions on bone quality.

Plant-derived soybean peroxidase stimulates osteoblast collagen biosynthesis, matrix mineralization, and accelerates bone regeneration in a sheep model

Bone defects arising from fractures or disease represent a significant problem for surgeons to manage and are a substantial economic burden on the healthcare economy. Recent advances in the development of biomaterial substitutes provides an attractive alternative to the current "gold standard" autologous bone grafting. Despite on-going research, we are yet to identify cost effective biocompatible, osteo-inductive factors that stimulate controlled, accelerated bone regeneration.We have recently reported that enzymes with peroxidase activity possess previously unrecognised roles in extracellular matrix biosynthesis, angiogenesis and osteoclastogenesis, which are essential processes in bone remodelling and repair. Here, we report for the first time, that plant-derived soybean peroxidase (SBP) possesses pro-osteogenic ability by promoting collagen I biosynthesis and matrix mineralization of human osteoblasts in vitro. Mechanistically, SBP regulates osteogenic genes responsible for inflammation, extracellular matrix remodelling and ossification, which are necessary for normal bone healing. Furthermore, SBP was shown to have osteo-inductive properties, that when combined with commercially available biphasic calcium phosphate (BCP) granules can accelerate bone repair in a critical size long bone defect ovine model. Micro-CT analysis showed that SBP when combined with commercially available biphasic calcium phosphate (BCP) granules significantly increased bone formation within the defects as early as 4 weeks compared to BCP alone. Histomorphometric assessment demonstrated accelerated bone formation prominent at the defect margins and surrounding individual BCP granules, with evidence of intramembranous ossification. These results highlight the capacity of SBP to be an effective regulator of osteoblastic function and may be beneficial as a new and cost effective osteo-inductive agent to accelerate repair of large bone defects.

Indicators and Recommendations for Assessing Sustainable Healthy Diets

Research coupling human nutrition and sustainability concerns is a rapidly developing field, which is essential to guide governments' policies. This critical and comprehensive review analyzes indicators and approaches to "sustainable healthy diets" published in the literature since this discipline's emergence a few years ago, identifying robust gauges and highlighting the flaws of the most commonly used models. The reviewed studies largely focus on one or two domains such as greenhouse gas emissions or water use, while overlooking potential impact shifts to other sectors or resources. The present study covers a comprehensive set of indicators from the health, environmental and socio-economic viewpoints. This assessment concludes that in order to identify the best food option in sustainability assessments and nutrition analysis of diets, some aspects such as the classification and disaggregation of food groups, the impacts of the rates of local food consumption and seasonality, preservation methods, agrobiodiversity and organic food and different production systems, together with consequences for low-income countries, require further analysis and consideration.

Partial Replacement of Animal Proteins with Plant Proteins for 12 Weeks Accelerates Bone Turnover Among Healthy Adults: A Randomized Clinical Trial

BACKGROUND

Plant-based diets may reduce the risk of chronic diseases, but can also lead to low calcium and vitamin D intakes, posing a risk for bone health.

OBJECTIVES

We investigated whether partial replacement of animal proteins with plant-based proteins using a whole-diet approach affects bone and mineral metabolism in healthy adults in 3 groups fed diets differing in protein composition.

METHODS

This 12-week clinical trial was comprised of 107 women and 29 men (20-69 years old; BMI mean ± SD, 24.8 ± 3.9) randomly assigned to consume 1 of 3 diets designed to provide 17 energy percent (E%) protein: "animal" (70% animal protein, 30% plant protein of total protein intake), "50/50" (50% animal, 50% plant), and "plant" (30% animal, 70% plant) diets. We examined differences in bone formation [serum intact procollagen type I amino-terminal propeptide (S-iPINP)], bone resorption [serum collagen type 1 cross-linked C-terminal telopeptide (S-CTX)], mineral metabolism markers (primary outcomes), and nutrient intakes (secondary outcomes) by ANOVA/ANCOVA.

RESULTS

S-CTX was significantly higher in the plant group (mean ± SEM, 0.44 ± 0.02 ng/mL) than in the other groups (P values < 0.001 for both), and differed also between the animal (mean ± SEM, 0.29 ± 0.02 ng/mL) and 50/50 groups (mean ± SEM, 0.34 ± 0.02 ng/mL; P = 0.018). S-iPINP was significantly higher in the plant group (mean ± SEM, 63.9 ± 1.91 ng/mL) than in the animal group (mean ± SEM, 55.0 ± 1.82 ng/mL; P = 0.006). In a subgroup without a history of vitamin D supplement use, plasma parathyroid hormone was significantly higher in the plant than in the animal group (P = 0.018). Vitamin D and calcium intakes were below recommended levels in the plant group (mean ± SEM, 6.2 ± 3.7 μg/d and 733 ± 164 mg/d, respectively).

CONCLUSIONS

Partial replacement of animal proteins with plant-based proteins for 12 weeks increased the markers of bone resorption and formation among healthy adults, indicating a possible risk for bone health. This is probably caused by lower vitamin D and calcium intakes from diets containing more plant-based proteins, but it is unclear whether differences in protein intake or quality play a major role. This trial was registered at clinicaltrials.gov as NCT03206827.

Nutrients to mitigate osteosarcopenia: the role of protein, vitamin D and calcium

PURPOSE OF REVIEW

Osteosarcopenia (the joint loss of bone density and muscle mass and function) is an emerging geriatric syndrome, which associates with poor health outcomes. Several nutrients including protein, vitamin D and calcium interact (directly or through absorption properties) to regulate muscle and bone metabolism. We provided an update on the efficacy of these nutrients on musculoskeletal outcomes in older adults with, or at risk of, osteosarcopenia.

RECENT FINDINGS

Randomized trials show that correcting vitamin D and calcium deficiencies to meet the recommended dietary allowance (RDA) increases bone density and reduces fracture (but not falls) risk. Supplementing above the RDA with protein supports gains in lean mass and lumbar-spine bone density; however, there is inconclusive evidence for muscle strength, physical function or other bone density sites. A likely explanation for this relates to the significant heterogeneity between trials regarding protein dose, type and timing, as well as baseline protein intake. Further high-quality trials are needed in older osteosarcopenic adults to investigate the effects of protein (while correcting vitamin D and calcium deficiencies) on clinically meaningful outcomes such as activities of daily living, falls and fractures.

SUMMARY

An adequate intake of protein (1.2-1.5 g/kg/day), vitamin D (800 IU/day) and calcium (1000-1200 mg/day), is well tolerated and effective at mitigating some aspects of osteosarcopenia such as lean mass, bone density and fracture risk.

Epigenetic therapies of osteoporosis

The study of epigenetics reaches its 50th anniversary, however, its clinical application is gradually coming into the clinical setting. Osteoporosis is one of the major and widely diffused bone diseases. Pathogenic mechanisms at the epigenetic level may interfere with bone remodeling occurring during osteoporosis. Preclinical models were used to understand whether such events may interfere with the disease. Besides, observational clinical trials investigated epigenetic-related biomarkers. This effort leads to some epigenetic-related therapies in clinical trials for the treatment of osteoporosis. Bisphosphonates (BPs), target therapy blocking RANK/RANKL pathway, and anti-sclerostin antibody (SOST) are the main therapeutic approaches. However, future large trials will reveal whether epigenetic therapies of osteoporosis will remain a work in progress or data will become more robust in the real-world management of these frailty patients.

Source and Composition in Amino Acid of Dietary Proteins in the Primary Prevention and Treatment of CKD

Nutrition is a cornerstone in the management of chronic kidney disease (CKD). To limit urea generation and accumulation, a global reduction in protein intake is routinely proposed. However, recent evidence has accumulated on the benefits of plant-based diets and plant-derived proteins without a clear understanding of underlying mechanisms. Particularly the roles of some amino acids (AAs) appear to be either deleterious or beneficial on the progression of CKD and its complications. This review outlines recent data on the role of a low protein intake, the plant nature of proteins, and some specific AAs actions on kidney function and metabolic disorders. We will focus on renal hemodynamics, intestinal microbiota, and the production of uremic toxins. Overall, these mechanistic effects are still poorly understood but deserve special attention to understand why low-protein diets provide clinical benefits and to find potential new therapeutic targets in CKD.

Protein intake and osteosarcopenic adiposity in Korean adults aged 50 years and older

Intake of plant-based protein and recommended protein intake are associated with a lower risk of osteosarcopenic adiposity (co-occurrence of osteopenia/osteoporosis, sarcopenia, and adiposity) in elderly Korean men.

INTRODUCTION

Osteosarcopenic adiposity (OSA) syndrome is defined as the concurrent presence of osteopenia/osteoporosis, sarcopenia, and adiposity and leads to negative functional and metabolic outcomes in late adulthood. This study aimed to investigate the association between OSA and protein intake in adults aged 50 or older.

METHODS

A population-based, cross-sectional survey was conducted using the Korea National Health and Nutrition Examination Survey 2008-2009 data and included 645 men and 706 women aged 50 or older. Subjects were classified into normal and OSA groups. Protein intake was analyzed using the 24-h recall method.

RESULTS

There was no significant difference in the intake of total protein and animal-based protein between normal and OSA groups. However, in males, the intake of plant-based protein (p = 0.0031) was significantly lower in the OSA group than that in the normal group. Further, the protein intake in the OSA group was 0.96 g/kg/day, which was significantly lower than that in the normal group (1.06 g/kg/day; p = 0.0203). After adjusting for confounding factors, men over 65 years old who consumed less than the recommended nutrient intake (RNI) of 0.91 g/kg/day had 5.82 times higher risk of OSA compared with subjects consuming protein equal to or greater than the RNI amount (95% CI 1.81-18.66).

CONCLUSION

In conclusion, a protein intake of RNI or more is associated with a lower risk of OSA in Korean elderly men.

Animal, Plant, Collagen and Blended Dietary Proteins: Effects on Musculoskeletal Outcomes

Dietary protein is critical for the maintenance of musculoskeletal health, where appropriate intake (i.e., source, dose, timing) can mitigate declines in muscle and bone mass and/or function. Animal-derived protein is a potent anabolic source due to rapid digestion and absorption kinetics stimulating robust increases in muscle protein synthesis and promoting bone accretion and maintenance. However, global concerns surrounding environmental sustainability has led to an increasing interest in plant- and collagen-derived protein as alternative or adjunct dietary sources. This is despite the lower anabolic profile of plant and collagen protein due to the inferior essential amino acid profile (e.g., lower leucine content) and subordinate digestibility (versus animal). This review evaluates the efficacy of animal-, plant- and collagen-derived proteins in isolation, and as protein blends, for augmenting muscle and bone metabolism and health in the context of ageing, exercise and energy restriction.

Is There Scope for a Novel Mycelium Category of Proteins alongside Animals and Plants?

In the 21st century, we face a troubling trilemma of expanding populations, planetary and public wellbeing. Given this, shifts from animal to plant food protein are gaining momentum and are an important part of reducing carbon emissions and consumptive water use. However, as this fast-pace of change sets in and begins to firmly embed itself within food-based dietary guidelines (FBDG) and food policies we must raise an important question-is now an opportunistic time to include other novel, nutritious and sustainable proteins within FBGD? The current paper describes how food proteins are typically categorised within FBDG and discusses how these could further evolve. Presently, food proteins tend to fall under the umbrella of being 'animal-derived' or 'plant-based' whilst other valuable proteins i.e., fungal-derived appear to be comparatively overlooked. A PubMed search of systematic reviews and meta-analytical studies published over the last 5 years shows an established body of evidence for animal-derived proteins (although some findings were less favourable), plant-based proteins and an expanding body of science for mycelium/fungal-derived proteins. Given this, along with elevated demands for alternative proteins there appears to be scope to introduce a 'third' protein category when compiling FBDG. This could fall under the potential heading of 'fungal' protein, with scope to include mycelium such as mycoprotein within this, for which the evidence-base is accruing.

Plant-based diets and bone health: sorting through the evidence

PURPOSE OF REVIEW

An increase in awareness of vegetarian and vegan (plant-based) diets has brought forth numerous studies on their effects on health. The study of nutrition-based factors affecting bone health is difficult, given the length of time before clinical effects are evident. Furthermore, population-based studies must account for strong confounding influences as effects may be because of association, not causality. Yet, it is highly plausible that dietary factors affect bone remodeling in multiple ways. Plant-based diets may alter macronutrient and micronutrient balance, may cause differences in prebiotic and probiotic effects on gut microbiota, and may subtly change the inflammatory and immune response.

RECENT FINDINGS

Several recent studies have looked at plant-based nutrition and markers of bone health, using measures such as bone turnover markers, bone mineral density, or fracture rates. Although population based and cross-sectional studies can be prone to confounding effects, a majority did not show differences in bone health between vegetarians/vegans and omnivores as long as calcium and vitamin D intake were adequate. A few prospective cohort or longitudinal studies even demonstrate some benefit to a plant-based diet, but this claim remains unproven.

SUMMARY

There is no evidence that a plant-based diet, when carefully chosen to maintain adequate calcium and vitamin D levels, has any detrimental effects on bone health. Theoretical findings suggest a long-term plant-based diet may reduce the risk of osteoporosis, through mechanisms that are currently speculative.

Optimizing Adult Protein Intake During Catabolic Health Conditions

The DRIs define a range of acceptable dietary intakes for each nutrient. The range is defined from the minimum intake to avoid risk of inadequacy (i.e., the RDA) up to an upper limit (UL) based on a detectable risk of adverse effects. For most nutrients, the minimum RDA is based on alleviating a clear deficiency condition, whereas higher intakes are often recommended to optimize specific health outcomes. Evidence is accumulating that similar logic should be applied to dietary recommendations for protein. Although the RDA for protein of 0.8 g/kg body weight is adequate to avoid obvious inadequacies, multiple studies provide evidence that many adults may benefit from protein quantity, quality, and distribution beyond guidelines currently defined by the RDA. Further, the dietary requirement for protein is a surrogate for the constituent amino acids and, in particular, the 9 considered to be indispensable. Leucine provides an important example of an essential amino acid where the RDA of 42 mg/kg body weight is significantly less than the 100-110 mg/kg required to optimize metabolic regulation and skeletal muscle protein synthesis. This review will highlight the benefits of higher protein diets to optimize health during aging, inactivity, bed rest, or metabolic dysfunction such as type 2 diabetes.