Frontiers in Nutrition最新文献

Background: Branched-chain amino acids (BCAAs) are widely used as sports nutrition supplements. However, their impact on the rate of force development (RFD), an indicator of explosive muscle strength, has not yet been validated. This study aimed to assess the impact of BCAA supplementation on the RFD in college basketball players during simulated games.

Methods: This study employed a randomized, controlled crossover, double-blind design. Participants received either BCAAs (0.17 g/kg combined with 0.17 g/kg isocaloric glucose) or a placebo (0.34 g/kg isocaloric glucose) orally 30 min before beginning the exercise protocol. The RFD was quantified using the isometric mid-thigh pull (IMTP) test. Additional outcome measures, including strength and jump tests, agility and sprinting tests, and physiological responses, were also assessed. A two-way repeated measures ANOVA was employed to evaluate the impact of supplements (BCAAs and placebo) on RFD and other related outcome measures.

Results: Analysis of the 50 ms RFD demonstrated significant main effects of BCAA supplementation (p = 0.003). The BCAAs group consistently exhibited higher levels of 50 ms RFD compared to the placebo group across rounds 1 to 4. For example, in round 1, the 50 ms RFD was 3702.3 ± 1223.2 N/S in the BCAAs group versus 2931.3 ± 888.8 N/S in the placebo group (p = 0.045). Although no significant between-group differences were observed for the 100, 150, 200, and 250 ms RFD measurements, the BCAAs group consistently showed superior values across all time points. The results of other outcome indicators also suggested that supplementation with BCAAs was indeed effective.

Conclusion: The results indicate that BCAA supplementation can enhance RFD in basketball players, particularly at the 50 ms RFD. Our research design provides reliable insights into the effects of BCAAs on athletic performance. Further studies of similar design with larger sample sizes are necessary to confirm and extend these findings.

Clinical trial registration: Chinese Clinical Trial Registry, ChiCTR2400091314 (https://www.chictr.org.cn).

Osteoarthritis (OA) is a common progressive degenerative disease. Gut microbiota (GM) and their metabolites have been closely associated with the onset, progression, and pathology of OA. GM and their metabolites may influence the cartilage directly, or indirectly by affecting the gut, the immune system, and the endocrine system. They function through classical pathways in cartilage metabolism and novel pathways that have recently been discovered. Some of them have been used as targets for the prevention and treatment of OA. The current study sought to describe the major pathological signaling pathways in OA chondrocytes and the potential role of gut-related factors in these pathways.

Objective: Monitoring dietary habits is crucial for identifying shortcomings and delineating countermeasures. About 20 years after the last population-based surveys in Bavaria and Germany, dietary habits were assessed to describe the intake distributions and compare these with recommendations at food and nutrient level.

Methods: The 3rd Bavarian Food Consumption Survey (BVS III) was designed as a diet survey representative of adults in Bavaria; from 2021 to 2023, repeated 24-h diet recalls were collected by telephone using the software GloboDiet©. Food (sub-)group and nutrient intake data were modeled with the so-called NCI method, weighted for the deviation from the underlying population. Intake distributions in men and women were described as percentiles. These data were used to estimate the proportion of persons meeting dietary intake recommendations. In addition, food consumption data were compared with the results reported 20 years ago collected by the same methodology (2nd Bavarian Food Consumption Survey, BVS II).

Results: Using 24-h diet recalls of 550 male and 698 female participants, we estimated intake distributions for food (sub-)groups and nutrients. A major proportion of the adult population does not meet the food-based dietary guidelines; this refers to a series of food groups, including fruit and vegetables, legumes, nuts, cereal products, and especially whole grain products, as well as fresh and processed meat. Regarding selected essential nutrients, a considerable proportion of the population was at higher risk of insufficiency from iron (women), zinc (men), and folate (both men and women), as already described in previous studies.

Conclusion: A major proportion of the adult Bavarian population does not meet the current food-based dietary guidelines. Compared to BVS II data, favorable changes refer to lower consumption of total meat (especially processed meat) and soft drinks, and an increased intake of vegetables. The conclusions based on the intake of selected essential nutrients hardly changed over time. From a public health perspective, the still low intake of vegetables, fruit, nuts, cereal products, and particularly of whole grain products, and associated higher risks of insufficient supply of several vitamins and minerals call for action for improvement.

Introduction: Frozen pork can reduce the quality of the meat and alter the digestibility and bioavailability of meat proteins in the human body. In this study, we investigated the changes in the basic composition during frozen storage and their effects on the structural properties of digestion products after protein digestion.

Methods: The impacts of frozen storage at different temperatures (-8, -18, -25, and -40°C) and for different times (1, 3, 6, 9, and 12 months) on the basic components and in vitro digestive characteristics of pork were evaluated.

Results: The moisture, crude fat, and protein contents decreased with extended storage and increased temperature, whereas muscle juice loss increased (p < 0.05). During in vitro digestion of samples frozen at -8°C for 12 months, trichloroacetic acid (TCA)-soluble peptides were decreased by 25.46% and 14.37% in the gastric and small intestinal phases, respectively, compared with fresh samples. Confocal laser scanning microscope (CLSM) showed that samples stored at -8°C had the largest particle size after digestion. Disruption of protein structure was confirmed by the decrease in α-helix, β-turn, and fluorescence intensity (all p < 0.05) and the increase in β-sheet, random coil, and maximum fluorescence wavelength of the digestion products of samples frozen at -8°C (all p < 0.05).

Discussion: Therefore, long-term high-temperature frozen storage brought about a significant decline in basic components of muscle and acceleration of loss of protein structural integrity after digestion.

Background: Short-chain fatty acids (SCFAs), derived from the fermentation of dietary fiber by intestinal commensal bacteria, have demonstrated protective effects against acute lung injury (ALI) in animal models. However, the findings have shown variability across different studies. It is necessary to conduct a comprehensive evaluation of the efficacy of these treatments and their consistency.

Objective: This systematic review and meta-analysis aimed to explore the effects of SCFAs on ALI based on preclinical research evidence, in order to provide new treatment strategies for ALI.

Methods: We included studies that tested the effects of SCFAs on ALI in animal models. This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search for relevant studies was conducted in the PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure (CNKI) databases up to February 2024. The data were extracted in accordance with the established selection criteria, and the risk of bias was evaluated for each study.

Results: A total of 16 articles were finally included in the meta-analysis. The results indicated that the SCFAs significantly reduced lung wet-to-dry weight (SMD = -2.75, 95% CI = -3.46 to -2.03, p < 0.00001), lung injury scores (SMD = -5.07, 95% CI = -6.25 to -3.89, p < 0.00001), myeloperoxidase (SMD = -3.37, 95% CI = -4.05 to -2.70, p < 0.00001), tumor necrosis factor-alpha (SMD = -3.31, 95% CI = -4.45 to -2.16, p < 0.00001) and malondialdehyde (SMD = -3.91, 95% CI = -5.37 to -2.44, p < 0.00001) levels in animal models of ALI. The results of the subgroup analysis indicated that the efficacy of SCFAs varies significantly with dosage and duration of treatment.

Conclusion: SCFAs can reduce inflammation and oxidative stress in animal models of ALI. The clinical efficacy of SCFAs for ALI deserves further in-depth research.

Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=584008, CRD42024584008.

Background and aim: Clinical data on the prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction and etiology-associated steatohepatitis (MetALD) in a multi-ethnic U.S. population are limited. Additionally, the impact of physical activity (PA) and diet quality (DQ) on the risk of MASLD, MetALD, and compensated advanced chronic liver disease (cACLD) remains unclear. This study aimed to investigate the associations of PA and diet quality with the risks of MASLD, MetALD, and cACLD.

Methods and results: This cross-sectional study analyzed data from 7,125 participants in the National Health and Nutrition Examination Survey (NHANES) 2017-2020. Diet quality was assessed using the Healthy Eating Index-2015 (HEI-2015). PA was assessed based on the 2020 WHO Physical Activity Guidelines, with participants reporting the intensity, frequency, and duration of their activities over the past 7 days. MASLD and MetALD were diagnosed based on clinical criteria, and cACLD was defined by advanced liver fibrosis. Bivariate and multivariable logistic regression models were used to assess associations between PA, diet quality, and liver disease outcomes. The prevalence of MASLD and MetALD was 35.07 and 21.46%, respectively. HQD was associated with significantly lower risks of MASLD (OR: 0.49, 95% CI: 0.38-0.62) and MetALD (OR: 0.45, 95% CI: 0.36-0.56). High PA levels were linked to reduced risks of MASLD (OR: 0.47, 95% CI: 0.38-0.58) and MetALD (OR: 0.53, 95% CI: 0.39-0.72). The lowest risks for both MASLD and MetALD were observed in highly active participants with an HQD (MASLD OR: 0.41, 95% CI: 0.32-0.53; MetALD OR: 0.54, 95% CI: 0.41-0.71). Significant interactions were observed between PA, HQD, and age, BMI, and SES, which further reduced the risks of MASLD and MetALD. For cACLD, both increased PA and HQD were associated with reduced risk. Compared to non-high-activity participants with a non-HQD, physically active participants with an HQD had the lowest risk of cACLD (OR: 0.44, 95% CI: 0.24-0.82).

Conclusion: High proportions of the US population have MASLD or MetALD. HQD and high PA levels were associated with lower risks of MASLD, MetALD, and cACLD.

Aims: The association between urinary caffeine and caffeine metabolites with sex hormones remains unclear. This study used three statistical models to explore the associations between urinary caffeine and its metabolites and sex hormones among adults.

Methods: We selected the participants aged ≥18 years in the National Health and Nutrition Examination Survey (NHANES) data 2013-2014 as our study subjects. We performed principal components analysis (PCA) to investigate the underlying correlation structure of urinary caffeine and its metabolites. Then we used these principal components (PCs) as independent variables to conduct multiple linear regression analysis to explore the associations between caffeine metabolites and sex hormones (E2, TT, SHBG). We also fitted weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) methods to further assess these relationships.

Results: In the PCA-multivariable linear regression, PC2 negatively correlates with E2: β = -0.01, p-value = 0.049 (male population). In the WQS regression model, the WQS indices were associated with SHBG and TT both in male (SHBG: WQS index = -0.11, p < 0.001; TT: WQS index = -0.10, p < 0.001) and female (SHBG: WQS index = -0.10, p < 0.001; TT: WQS index = -0.04, p < 0.001) groups. Besides, the WQS index was significantly associated with E2 in females (p < 0.05). In the BKMR model, despite no significant difference in the overall association between caffeine metabolites and the sex hormones (E2, TT, SHBG), there was nonetheless a declining trend in the male population E2 group, in the male and female population SHBG groups also observed a downward trend.

Conclusion: When considering the results of these three models, the whole-body burden of caffeine metabolites, especially the caffeine metabolites in the PC2 metabolic pathway was significantly negatively associated with E2 in males. Considering the advantages and disadvantages of the three statistical models, we recommend applying diverse statistical methods and interpreting their results together.

Objective: Patients with Crohn's disease (CD) commonly experience malnutrition. The Global Leadership Initiative on Malnutrition (GLIM) criteria, a novel approach to assessing malnutrition, has been validated in some diseases. However, there are limited studies in CD patients. This study aimed to investigate the applicability and effectiveness of the simplified GLIM criteria for evaluating the nutritional status of patients with Crohn's disease. Additionally, it sought to evaluate the correlation between malnutrition defined by simplified GLIM and clinical outcomes.

Methods: A retrospective cohort study was conducted with 386 patients with CD. Data were extracted from the medical records, including demographic and clinical characteristics. All patients were evaluated using the simplified GLIM criteria. The prevalence of malnutrition was reported and the relationship between malnutrition and clinical outcome was analyzed.

Results: The prevalence of malnutrition among patients with CD was 73.6%, with 36.5% classified as moderate malnutrition and 37.0% classified as severe malnutrition. The malnourished group had significantly higher Crohn's Disease Activity Index (CDAI) scores compared to the non-malnourished group (p < 0.001). Furthermore, the malnutrition group exhibited significantly lower levels of specific nutritional indicators, including hemoglobin (p = 0.040), albumin (p = 0.015), and prealbumin (p = 0.021). The median duration of follow-up in the cohort was 15.2 weeks. The results indicated that malnutrition, as assessed by simplified GLIM, independently influenced endoscopic remission (p = 0.033). Additionally, the duration of disease (p = 0.021), C-reactive protein (p = 0.014) and prealbumin (p = 0.014) were independent factors influencing endoscopic remission in patients with CD.

Conclusion: Malnutrition identified using the simplified GLIM criteria is associated with age, CDAI, behavior, hemoglobin, and albumin, providing prognostic value for endoscopic remission in CD patients.