Diets High in Fiber and Vegetable Protein Are Associated with Low Lumbar Bone Mineral Density in Young Athletes with Oligoamenorrhea

Subchronic toxic effects of bisphenol A on the gut-liver-hormone axis in rats via intestinal flora and metabolism

Background

Bisphenol A (BPA), a characteristic endocrine disruptor, is a substance that seriously interferes with the human endocrine system and causes reproductive disorders and developmental abnormalities. However, its toxic effects on the gut-liver-hormone axis are still unclear.

Method

Male and female rats were exposed to BPA (300 mg/kg) by oral gavage for 60 consecutive days. H&E staining was used for histopathological evaluation, and the serum biochemical indexes were determined using an automatic analyzer. The 16S rRNA gene sequencing was used to detect the intestinal microbial diversity, and the GC-MS was used to analyze the contents of short-chain fatty acids (SCFAs) in colon contents. UPLC-QTOF MS was used to analyze the related metabolites. The ELISA method was used to assess the levels of serum inflammatory factors.

Results

Histopathological analysis indicated that the liver, heart, and testis were affected by BPA. There was a significant effect on alanine aminotransferase (ALT), triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL) in the male-BPA group (P < 0.05), and globulin (GLB), indirect bilirubin (IBIL), alkaline phosphatase (ALP), ALT, TG, TC, high-density lipoprotein (HDL), and creatinine (Cr) in the female-BPA group (P < 0.05). Metagenomics (16S rRNA gene sequencing) analysis indicated that BPA reduced the diversity and changed the composition of gut microbiota in rats significantly. Compared with the control and blank groups, the contents of caproic acid, isobutyric acid, isovaleric acid, and propanoic acid in the colon contents decreased in the male-BPA group (P < 0.05), and caproic acid, isobutyric acid, isovaleric acid, and valeric acid in the colon contents decreased in the female-BPA group (P < 0.05). Metabolomic analysis of the serum indicated that BPA could regulate bile acid levels, especially ursodeoxycholic acid (UDCA) and its conjugated forms. The contents of amino acids, hormones, and lipids were also significantly affected after exposure to BPA. The increase in interleukin-6 (IL-6), interleukin-23 (IL-23), and transforming growth factor-β (TGF-β) in the serum of the male-BPA group suggests that BPA exposure affects the immune system.

Conclusion

BPA exposure will cause toxicity to rats via disrupting the gut-liver-hormone axis.

Plant-Based Proteins, Peptides and Amino Acids in Food Products Dedicated for Sportspeople-A Narrative Review of the Literature

Plant proteins are increasingly seen as critical nutrient sources for both amateur and professional athletes. The aim of the presented study was to review the inventions and experimental articles referring to the application of plant-based proteins, peptides and amino acids in food products dedicated to sportspeople and published in the period 2014-2023. The literature search was conducted according to PRISMA statementsacross several key databases, including Scopus and ISI Web of Science. Altogether, 106 patents and 35 original articles were found. The survey of patents and inventions described in the articles showed the use of 52 taxa (mainly annual herbaceous plants), creating edible seeds and representing mainly the families Fabaceae and Poaceae. The majority of inventions were developed by research teams numbering from two to five scientists, affiliated in China, The United States of America and Japan. The greatest number of inventions applied plant-based proteins (especially protein isolates), declared the nutritional activity and were prepared in liquid or solid consistency. According to the reviewed studies, the intake of soybean and potato proteins might provide better results than animal-based protein (excluding resistance training), whereas the consumption of pea and rice protein does not possess any unique anabolic properties over whey protein. The analysis of other investigations demonstrated the varied acceptability and consumption of food products, while the high rating of the tested food products presented in four articles seems to be an effect of their sensual values, as well as other elements, such as production method, health benefits and cost-effectiveness. Considering the great potential of useful plant species, it might be concluded that future investigations focusing on searching for novel plant protein sources, suitable for the preparation of food products dedicated to amateur and professional sportspeople, remain of interest.

Effects of a 16-Week Digital Intervention on Sports Nutrition Knowledge and Behavior in Female Endurance Athletes with Risk of Relative Energy Deficiency in Sport (REDs)

Female endurance athletes are considered a high-risk group for developing Relative Energy Deficiency in Sport (REDs). Due to the lack of educational and behavioral intervention studies, targeting and evaluating the effects of the practical daily management of REDs, we developed the Food and nUtrition for Endurance athletes-a Learning (FUEL) program, consisting of 16 weekly online lectures and individual athlete-centered nutrition counseling every other week. We recruited female endurance athletes from Norway (n = 60), Sweden (n = 84), Ireland (n = 17), and Germany (n = 47). Fifty athletes with symptoms of REDs and with low risk of eating disorders, with no use of hormonal contraceptives and no chronic diseases, were allocated to either the FUEL intervention (n = 32) (FUEL) or a 16-week control period (n = 18) (CON). All but one completed FUEL, while 15 completed CON. We found strong evidence for improvements in sports nutrition knowledge, assessed via interviews, and moderate to strong evidence in the ratings concerning self-perceived sports nutrition knowledge in FUEL versus CON. Analyses of the seven-day prospective weighed food record and questions related to sports nutrition habits, suggested weak evidence for improvements in FUEL versus CON. The FUEL intervention improved sports nutrition knowledge and suggested weak evidence for improved sports nutrition behavior in female endurance athletes with symptoms of REDs.

Dietary Fiber Intake and Femoral Bone Mineral Density in Middle-Aged and Older US Adults: A Cross-Sectional Study of National Health and Nutrition Examination Survey 2013-2014

Sufficient dietary fiber intake (DFI) is considered necessary for human health. However, the association between DFI and bone mineral density (BMD) remains unclear. Therefore, this study aimed to investigate the association between DFI and BMD and to determine whether sex modifies the association between DFI and BMD. Participants aged ≥ 40 years from the 2013-2014 National Health and Nutrition Examination Survey were included in the final analysis. The association between DFI and BMD was evaluated using a multivariate linear regression model. The non-linear relationship between DFI and BMD was characterized by smooth curve fittings and generalized additive models. Finally, 1,935 participants with a mean age of 58.12 ± 11.84 years were included in the final analysis. The results revealed that DFI was positively associated with femoral BMD in the unadjusted model. However, no correlation was observed between DFI and femoral BMD after adjusting for covariates. Moreover, the results showed an inverted U-shaped association between total DFI and femoral BMD among men but not women for the nonlinear relationship between DFI and femoral BMD. In conclusion, our results indicate that DFI might not follow a linear relationship with femoral BMD, and sex factors might modify the association between DFI and BMD. Particularly, high total DFI might contribute to lower femoral neck BMD. However, more studies are needed to investigate whether the negative effect of high DFI on femoral BMD does exist and whether high DFI has clear biological effects on bone metabolism, such as increasing the risk of osteoporosis.

AEROBIC AND ANAEROBIC EXERCISE ABILITY OF ATHLETES COMBINED WITH BALANCED NUTRITION

ABSTRACT Balanced nutrition is very important for athletes’ health and competition performance, and balanced nutrition has become a hot topic in the sports industry. In this study, 30s anaerobic work test and maximal oxygen uptake test were used to test anaerobic exercise ability and aerobic exercise ability, respectively. Four groups were set up in the two test methods, and the corresponding functional test indexes, heart rate recovery index and blood lactic acid recovery value were determined. The anaerobic capacity test showed that the maximum power of male athletes in the experimental group had significant statistical difference before and after dietary balance management, and the fatigue index of female athletes in the experimental group had a significant downward trend. Five minutes and nine minutes after exercise, the blood lactic acid value of males in the experimental group was lower than before balanced nutrition. The aerobic capacity test showed that the exhaustion time of male athletes in the experimental group was significantly different before and after balanced nutrition. After the balanced nutrition, the blood lactic acid value of male athletes in the experimental group was lower than before the management immediately and nine minutes after exercise, and the heart rate value of the male athletes in the experimental group was far lower than before the management.

A Review of Nonpharmacological Strategies in the Treatment of Relative Energy Deficiency in Sport

Relative energy deficiency in sport (RED-S) can result in negative health and performance outcomes in both male and female athletes. The underlying etiology of RED-S is low energy availability (LEA), which occurs when there is insufficient dietary energy intake to meet exercise energy expenditure, corrected for fat-free mass, leaving inadequate energy available to ensure homeostasis and adequate energy turnover (optimize normal bodily functions to positively impact health), but also optimizing recovery, training adaptations, and performance. As such, treatment of RED-S involves increasing energy intake and/or decreasing exercise energy expenditure to address the underlying LEA. Clinically, however, the time burden and methodological errors associated with the quantification of energy intake, exercise energy expenditure, and fat-free mass to assess energy availability in free-living conditions make it difficult for the practitioner to implement in everyday practice. Furthermore, interpretation is complicated by the lack of validated energy availability thresholds, which can result in compromised health and performance outcomes in male and female athletes across various stages of maturation, ethnic races, and different types of sports. This narrative review focuses on pragmatic nonpharmacological strategies in the treatment of RED-S, featuring factors such as low carbohydrate availability, within-day prolonged periods of LEA, insufficient intake of bone-building nutrients, lack of mechanical bone stress, and/or psychogenic stress. This includes the implementation of strategies that address exacerbating factors of LEA, as well as novel treatment methods and underlying mechanisms of action, while highlighting areas of further research.

Pitfalls of Conducting and Interpreting Estimates of Energy Availability in Free-Living Athletes

The human body requires energy for numerous functions including, growth, thermogenesis, reproduction, cellular maintenance, and movement. In sports nutrition, energy availability (EA) is defined as the energy available to support these basic physiological functions and good health once the energy cost of exercise is deducted from energy intake (EI), relative to an athlete’s fat-free mass (FFM). Low EA provides a unifying theory to link numerous disorders seen in both female and male athletes, described by the syndrome Relative Energy Deficiency in Sport, and related to restricted energy intake, excessive exercise or a combination of both. These outcomes are incurred in different dose–response patterns relative to the reduction in EA below a “healthy” level of ∼45 kcal·kg FFM−1·day−1. Although EA estimates are being used to guide and monitor athletic practices, as well as support a diagnosis of Relative Energy Deficiency in Sport, problems associated with the measurement and interpretation of EA in the field should be explored. These include the lack of a universal protocol for the calculation of EA, the resources needed to achieve estimates of each of the components of the equation, and the residual errors in these estimates. The lack of a clear definition of the value for EA that is considered “low” reflects problems around its measurement, as well as differences between individuals and individual components of “normal”/“healthy” function. Finally, further investigation of nutrition and exercise behavior including within- and between-day energy spread and dietary characteristics is warranted since it may directly contribute to low EA or its secondary problems.

LS, Bruening. KS, Scerpella. TA, Dowthwaite. JN. Relationships among diet, physical activity, and dual plane dual-energy X-ray absorptiometry bone outcomes in pre-pubertalgirls

In pre-pubertal girls, nutrient intakes and non-aquatic organized activity were evaluated as factors in vertebral body bone mass, structure, and strength. Activity, vitamin B₁₂, and dietary fiber predicted bone outcomes most consistently. Exercise and vitamin B₁₂ appear beneficial, whereas high fiber intake appears to be adverse for vertebral body development.

PURPOSE

Childhood development sets the baseline for adult fracture risk. Most studies evaluate development using postero-anterior (PA) dual-energy X-ray absorptiometry (DXA) areal bone mineral density, bone mineral content, and bone mineral apparent density. In a prior analysis, we demonstrated that PA DXA reflects posterior element properties, rather than vertebral body fracture sites, such that loading is associated with subtle differences in vertebral body geometry, not 3D density. The current analysis is restricted to pre-pubertal girls, for a focused exploration of key nutrient intakes and physical activity as factors in dual plane indices of vertebral body geometry, density, and strength.

METHODS

This cross-sectional analysis used paired PA and supine lateral (LAT) lumbar spine DXA scans to assess "3D" vertebral body bone mineral apparent density (PALATBMAD), "3D" index of structural strength in axial compression (PALATIBS), and fracture risk index (PALATFRI). Diet data were collected using the Youth/Adolescent Questionnaire (YAQ, 1995); organized physical activity was recorded via calendar-based form. Pearson correlations and backward stepwise multiple linear regression analyzed associations among key nutrients, physical activity, and bone outcomes.

RESULTS

After accounting for activity and key covariates, fiber, unsupplemented vitamin B₁₂, zinc, carbohydrate, vitamin C, unsupplemented magnesium, and unsupplemented calcium intake explained significant variance for one or more bone outcomes (p < 0.05). After adjustment for influential key nutrients and covariates, activity exposure was associated with postero-anterior (PA) areal bone mineral density, PA bone mineral content, PA width, lateral (LAT) BMC, "3D" bone cross-sectional area (coronal plane), "3D" PALATIBS, and PALATFRI benefits (p < 0.05).

CONCLUSIONS

Physical activity, fiber intake, and unsupplemented B₁₂ intake appear to influence vertebral body bone mass, density, geometry, and strength in well-nourished pre-pubertal girls; high fiber intakes may adversely affect childhood vertebral body growth.

Bone microarchitecture in adolescent boys with autism spectrum disorder

BACKGROUND

Boys with autism spectrum disorder (ASD) have lower areal bone mineral density (aBMD) than typically developing controls (TDC). Studies of volumetric BMD (vBMD) and bone microarchitecture provide information about fracture risk beyond that provided by aBMD but are currently lacking in ASD.

OBJECTIVES

To assess ultradistal radius and distal tibia vBMD, bone microarchitecture and strength estimates in adolescent boys with ASD compared to TDC.

DESIGN/METHODS

Cross-sectional study of 34 boys (16 ASD, 18 TDC) that assessed (i) aBMD at the whole body (WB), WB less head (WBLH), hip and spine using dual X-ray absorptiometry (DXA), (ii) vBMD and bone microarchitecture at the ultradistal radius and distal tibia using high-resolution peripheral quantitative CT (HRpQCT), and (iii) bone strength estimates (stiffness and failure load) using micro-finite element analysis (FEA). We controlled for age in all groupwise comparisons of HRpQCT and FEA measures. Activity questionnaires, food records, physical exam, and fasting levels of 25(OH) vitamin D and bone markers (C-terminal collagen crosslinks and N-terminal telopeptide (CTX and NTX) for bone resorption, N-terminal propeptide of Type 1 procollagen (P1NP) for bone formation) were obtained.

RESULTS

ASD participants were slightly younger than TDC participants (13.6 vs. 14.2years, p=0.44). Tanner stage, height Z-scores and fasting serum bone marker levels did not differ between groups. ASD participants had higher BMI Z-scores, percent body fat, IGF-1 Z-scores, and lower lean mass and aBMD Z-scores than TDC at the WB, WBLH, and femoral neck (P<0.1). At the radius, ASD participants had lower trabecular thickness (0.063 vs. 0.070mm, p=0.004), compressive stiffness (56.7 vs. 69.7kN/mm, p=0.030) and failure load (3.0 vs. 3.7kN, p=0.031) than TDC. ASD participants also had 61% smaller cortical area (6.6 vs. 16.4mm2, p=0.051) and thickness (0.08 vs. 0.22mm, p=0.054) compared to TDC. At the tibia, ASD participants had lower compressive stiffness (183 vs. 210kN/mm, p=0.048) and failure load (9.4 vs. 10.8kN, p=0.043) and 23% smaller cortical area (60.3 vs. 81.5mm2, p=0.078) compared to TDC. A lower proportion of ASD participants were categorized as "very physically active" (20% vs. 72%, p=0.005). Differences in physical activity, calcium intake and IGF-1 responsiveness may contribute to group differences in stiffness and failure load.

CONCLUSION

Bone microarchitectural parameters are impaired in ASD, with reductions in bone strength estimates (stiffness and failure load) at the ultradistal radius and distal tibia. This may result from lower physical activity and calcium intake, and decreased IGF-1 responsiveness.

Peripheral skeleton bone strength is positively correlated with total and dairy protein intakes in healthy postmenopausal women

BACKGROUND

Bone mineral content (BMC) and bone mineral density (BMD) are positively correlated with dietary protein intakes, which account for 1-8% of BMC and BMD variances. However, the relation between bone strength and microstructure, which are variables that are not captured by areal bone mineral density (aBMD), and dietary protein intakes, particularly from specific dietary sources, has not been clearly established.

OBJECTIVE

We investigated the association between the peripheral skeleton-predicted failure load and stiffness, bone microstructure, and dietary protein intakes from various origins (animal, divided into dairy and nondairy, and vegetable origins) in healthy postmenopausal women.

DESIGN

In a cross-sectional study in 746 Caucasian women aged 65.0 ± 1.4 y, we measured the aBMD with the use of dual-energy X-ray absorptiometry, the distal radius and tibia bone microstructures with the use of high-resolution peripheral quantitative computerized tomography, and bone strength with the use of a finite element analysis, and we evaluated dietary protein and calcium with the use of a validated food-frequency questionnaire.

RESULTS

Mean dietary calcium and protein intakes were greater than recommended amounts for this class of age. The predicted failure load and stiffness at the distal radius and tibia were positively associated with total, animal, and dairy protein intakes but not with vegetable protein intake. Failure load differences were accompanied by modifications of the aBMD and of cortical and trabecular bone microstructures. The associations remained statistically significant after adjustment for weight, height, physical activity, menopause duration, calcium intake, and the interaction between calcium and protein intake. A principal component analysis of the volumetric BMD and bone microstructure indicated that trabecular bone mainly contributed to the positive association between protein intakes and bone strength.

CONCLUSIONS

These results, which were recorded in a very homogeneous population of healthy postmenopausal women, indicate that there is a beneficial effect of animal and dairy protein intakes on bone strength and microstructure. Specifically, there is a positive association between the bone failure load and stiffness of the peripheral skeleton and dietary protein intake, which is mainly related to changes in the trabecular microstructure. This trial was registered at www.controlled-trials.com as ISRCTN11865958.