Vitamin D3 has a preventive, anti-inflammatory effect. However, there are still few studies linking the effects of athlete training to vitamin D3 supplementation and the immune response. The study evaluated the impact of vitamin D3 supplementation on interleukin 6 (IL-6) release during physical exercise in relation to C-reactive protein (CRP) levels in healthy male athletes. Twenty-five soccer players were divided into two groups—with (GS) and without (GN) vitamin D3 supplementation in a dose of 20,000 IU twice a week for 8 wk (about 6,000 IU/d). At the baseline (T1) and at the end (T2) of the training cycle serum concentrations of 25-hydroxyvitamin D [25(OH)D], IL-6 and CRP were measured. In the GS group, we observed a significant increase in 25(OH)D concentration (p=0.004), and non-significantly increased levels (p>0.05) of IL-6 and CRP. At the baseline, CRP in the supplemented athletes who had suboptimal vitamin D3 concentration in T1 (GSO) was significantly higher than in those with an optimal baseline vitamin D3 level (GO) (p=0.028). However, in GO in T2, a non-significant trend of negative correlation (p=0.055) between 25(OH)D concentration and IL-6 level was found. In the total study group (TG), a statistically significant (p=0.021) negative correlation in T1 was observed between 25(OH)D and CRP. However, our results do not support the immune-modulatory effect of vitamin D3 supplementation in a dose of 6,000 IU/d in athletes, in relation to IL-6 production and its subsequent stimulatory effect on CRP releasing.

Solute carrier family 23 member 1 (SVCT1) and solute carrier family 23 member 2 (SVCT2), encoded by SLC23A1 and SLC23A2, may be associated with preeclampsia (PE). The purpose of this study was to investigate the association between polymorphisms of SLC23A1 and SLC23A2 and PE in Chinese Han population. The primers and double-labeled probes were designed according to the SNPs of rs10063949 in SLC23A1, rs6133175 and rs1279683 in SLC23A2. Genomic DNA was extracted from peripheral blood of 2,066 subjects (1,029 with PE and 1,037 without PE), and Taqman real-time PCR was used to detect the three SNPs. We observed a significant difference in genotypic frequency of the SLC23A2 rs6133175 polymorphism (χ²=8.08, p=0.02) between PE patients and controls, while no significant differences were found in the allelic frequencies (χ²=1.45, p=0.23). Then we fractionized these samples into the dominant model of the allele G (GG/AG+AA group) or the recessive model of the A allele (AA/AG+GG group), and observed a significant difference under the recessive model of the A allele (p=0.01, OR=0.71, 95% CI 0.55–0.92). Furthermore, there were no significant differences in the genotypic and allelic frequencies of rs10063949 and rs1279683 between PE patients and controls (for rs10063949, χ²=2.96, p=0.23 by genotype, χ²=2.11, p=0.15 by allele; for rs1279683, χ²=1.52, p=0.47 by genotype, χ²=0.64, p=0.44 by allele). We first found that SLC23A2 rs6133175 may be the certain genetic polymorphisms modulating their effects in the development of PE in a Chinese Han population and the AG or GG genotypes may be a risk factor for PE.

Maternal nutrition during pregnancy is one of the factors affecting the health of offspring. There are conflicting findings about the association between maternal vitamin D status and the development of allergic diseases in offspring. The purpose of this study is to evaluate the association between maternal vitamin D intake and the development of allergic diseases in offspring at 1 y of age. From an ongoing nationwide birth cohort study (the Japan Environment and Children’s Study), we obtained information on maternal vitamin D intake, determined by a food frequency questionnaire, and parent-reported physician-diagnosed allergic diseases in offspring at 1 y of age. From the full dataset of 103,062 pregnancies, we analyzed complete data for 82,592 mother–offspring pairs. The prevalence of physician-diagnosed asthma, food allergy, and atopic dermatitis in the children was 2.5%, 6.6%, and 4.3%, respectively. The mean (± standard deviation) maternal vitamin D intake was 4.7±4.7 μg/d, which is much lower than the recommended amount in Japan (7 μg/d). After adjustment for various covariates, the odds ratios were significantly higher for asthma in the 2nd quintile and for food allergies in the 3rd and 4th quintiles compared with the 1st quintile. However, there were no clear associations between maternal vitamin D intake and the development of allergic diseases in offspring at 1 y of age, even in a large nation-wide cohort study. Protective effects of vitamin D supplementation remain unclear.

The indicator amino acid oxidation method is a relatively new method for determining protein requirements. Our hypothesis was that the protein requirement of the casein-whey protein mixture (70% casein and 30% whey protein) was lower than the protein requirement of plain casein, because casein and whey proteins compensate for the lack of the first-limiting amino acids. The optimal mixing ratio was determined based on the amino acid scoring pattern which is used to calculate the digestible indispensable amino acid score. In this study, digestibility was not considered to determine the optimal mixing ratio because dairy protein is a good source of digestible protein. This study aimed to evaluate the protein requirements of Japanese young men by consuming casein and casein-whey protein mixture. Ten healthy young men (22±0.2 y old) participated in 12 experiments according to a graded protein intake (0.5, 0.7, 0.9, 1.0, 1.2, 1.4 g/kg/d) of casein and casein-whey protein mixture. The mean protein requirement was calculated as the breakpoint of breath ¹³CO₂ enrichment using change-point regression models. The mean protein requirements of Japanese young men by consuming casein and casein-whey protein mixture were estimated to be 1.00 g/kg/d and 0.90 g/kg/d, respectively. These estimated requirements were consistent with the protein quality expected from the amount of the first-limiting amino acids. The indicator amino acid oxidation method may be useful to evaluate protein quality.

In Japan, fees for nutritional management (NM) was introduced in April 2009 to improve nutritional care for persons with disabilities residing in welfare facilities. The present study aimed to clarify (1) the nutritional status as well as eating-related functions and behaviors of such residents and (2) status of incorporating claim fees for NM and oral maintenance in facilities supporting persons with disabilities. This cross-sectional study approached 2,510 welfare facilities for persons with disabilities across Japan. Anonymous questionnaire surveys were conducted in August 2018. Among the 1,543 responses, 1,538 (61.3%) were valid for analysis. The median number of residents in a facility was 50. Among all residents (n=80,322), 16.9% were underweight (body mass index [BMI]<18.5) and 14.5% were obese (BMI≥25.0). Of the residents, 38.9% adjusted food form and 15.2% had eating behavior-related problems. In total, 723 (47.0%) and 54 (3.5%) facilities, claimed the fees for NM and oral maintenance, respectively. The main reasons for not implementing the claim fees for NM was the lack of time for nutritional care and management (NCM; 30.2%), absence of a registered dietitian (29.3%), and difficulty in assessing swallowing function (24.1%). Our results revealed that the implementation rates of claim fees for NM and oral maintenance were low despite most respondents having problems with the double burden of malnutrition and necessity of oral care, suggesting the importance of securing time for NCM, appointing registered dietitians, and evaluating swallowing function.

The purpose of this study was to examine the association between dietary protein intake and the risk of type 2 diabetes mellitus (T2DM) among a Chinese rural elderly population. We used the demographic and dietary information of adults over age 65 in the Henan Rural Cohort Study to identify and pair 950 T2DM patients with healthy controls in a 1 : 1 matched case-control study. Dietary data was collected through a Food Frequency Questionnaire. A multivariate logistic regression model was applied to calculate the odds ratio (OR) and 95% confidence interval (CI) of T2DM risk according to protein intake. After adjustment for confounding factors, higher intake of total protein was negatively associated with T2DM risk in the total population (extreme-tertile OR=0.75, 95% CI: 0.58–0.93) and women (extreme-tertile OR=0.84, 95% CI: 0.47–0.93). Multivariate-adjusted ORs for the risk of T2DM in the highest compared with lowest tertile of plant protein intake in the total population and in women were 0.86 (95% CI: 0.60–0.84) and 0.58 (95% CI: 0.36–0.95), respectively. Our results suggest that the protein intake, especially plant protein, has a significant association with the risk of T2DM in rural elderly populations, and the sources of protein may be also important in future guidelines.

Nonalcoholic steatohepatitis (NASH) is associated with several cardiovascular risk factors, including atherogenic dyslipidemia. Recently, fasting prior to lipid profile evaluation has been thought to be unnecessary for most individuals. We investigated the impact of fasting for up to 9 h on the serum and hepatic lipid profiles in Sprague-Dawley (SD) rats of dietary-induced NASH model in comparison to SD rats fed a normal diet. In both groups, fasting affected the serum and hepatic triglyceride (TG), serum free fatty acid (FFA) and leptin levels, histopathologically assessed hepatocyte ballooning, and hepatic mRNA expression levels of several genes related to lipid metabolism. In contrast, the serum adiponectin and aminotransferase levels, serum and hepatic total cholesterol contents, and liver histopathological findings of hepatic steatosis, lobular inflammation and fibrosis were not influenced by fasting. A significant fasting time-dependent reduction was seen in the serum TG level only in the normal SD rats group. Regarding the hepatic TG level, a significant fasting time-dependent increase was seen only in the NASH model rat group. A significant fasting time-dependent reduction was also seen in the serum FFA level only in the NASH model rat group. Our present results indicate that excessive fasting can be avoided before blood or hepatic tissue sampling for the evaluation of several parameters in non-NASH and/or NASH model rats. Further investigations are needed in humans to determine whether excessive fasting before blood or hepatic tissue sampling can be avoided in both healthy individuals and NASH patients.

Vitamin D and its receptor (vitamin D receptor; VDR) regulate calcium homeostasis in mammals. Recently, studies have shown that serum concentrations of 25-hydroxyvitamin D (25VD) are negatively associated with insulin resistance and the incidence of type 2 diabetes. In adipose tissues, glucose transporter 4 (GLUT4) contributes to insulin-stimulated glucose uptake; however, the effect of 25VD on glucose uptake in adipocytes remains unclear. We examined the role of 25VD in glucose uptake and the differentiation of adipose-derived stromal cells. Insulin-stimulated glucose uptake in adipocytes was increased by treatment with 25VD and decreased by VDR knockdown. The expression levels of GLUT4 were upregulated by 25VD treatment. 25VD exposure increased the expression of adipocyte differentiation-related genes including peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding proteins through VDR, thereby enhancing the formation of mature adipocytes. Moreover, 25VD increased the expression levels of 11β-hydroxysteroid dehydrogenase 1 (HSD11B1), which catalyzes the conversion of cortisone to cortisol in a concentration-dependent manner. 25VD-stimulated adipocyte differentiation was suppressed by HSD11B1 knockdown. Cortisone together with 25VD enhanced adipocyte differentiation, whereas synthesized glucocorticoid dexamethasone-induced adipocyte differentiation is not promoted by 25VD. Overall, these results indicate that 25VD stimulates adipocyte differentiation through the induction of HSD11B1 expression, leading to increased insulin-induced glucose uptake in adipocytes.

With the growing interest in healthy and sustainable diets, studying diets with high nutritional quality and low environmental impact is needed. We focused on the nitrogen footprint (NFP)—an indicator of reactive nitrogen loss that causes various environmental impacts—of Japanese diets using individual dietary records and identified the characteristics of lower NFP diets. This cross-sectional study was a secondary data analysis from the 2017 Saitama Prefecture Nutrition Survey. We analyzed the data obtained from a questionnaire and two-day dietary records of 479 men and women aged 30–65 y who had no misreported or missing data. The NFP was calculated using the virtual nitrogen factors of each food group reported in a previous study. After assessing NFP and its contributions, we conducted sub-group analysis for participants with appropriate weight status and adequate protein intake, classifying them into three groups according to tertiles of NFP to protein ratio. We compared NFP, its contributions, and nutrient intake between the groups. The total NFP (kg N/y) was 18.2±5.0 in men and 16.1±4.4 in women. In the sub-group analysis, total NFPs of the lower NFP group were 16.5±3.1 in men and 13.6±2.8 in women. Cereals, pulses, and fish and seafood contributed more significantly to the total NFP in the lower NFP group than in the higher NFP group. These results suggest that adequate protein intake from a variety of food sources is required to lower the environmental impact of adequate diets.

The present study was conducted to determine the antidiabetic effect of Momordica charantia (MC) on pancreatic islets of Langerhans in streptozotocin (STZ)-induced diabetic male Wistar rats in relation to the distribution of insulin immuno-positive beta cells. MC was fed to rats at 2, 5, and 10% of the standard diet for 12 wk. After sacrification, the pancreatic tissues were obtained for histopathological and immunohistochemical observations. In addition, monitoring of fasting blood glucose was applied each month during experimental period. The results revealed that the oral doses of MC at 5% and 10% of the daily diet increased the percentage of insulin-positive pancreatic beta cells as well as the size and number of pancreatic islets. Moreover, significant (p≤0.0001) dose and time-depended reduction in fasting blood glucose levels were observed. In conclusion, these results suggest that MC induces antidiabetic effects via regeneration of insulin-positive pancreatic beta cells and increase the number of insulin secretory granules hence, blood glucose reduction.

1-Kestose (kestose) is the smallest fructooligosaccharide component and shows a particularly high prebiotic function. Both kestose and the bile acid metabolite isoallolithocholic acid (isoalloLCA) are known to be beneficial for human health, especially in terms of immune homeostasis in the gastrointestinal system; however, the effect of kestose on the levels of microbial isoalloLCA producers remains to be clarified. IsoalloLCA is known to be produced by several members of the phylum Bacteroidota that carry the 5α-reductase (5AR) gene, a key isoalloLCA biosynthetic gene. Thus, we designed a specific primer set to detect the 5AR gene based on the consensus sequences of the genes from several isoalloLCA producers. Using real-time quantitative PCR with this primer set and fecal DNA samples, we compared the 5AR gene level (5ar-level) in the intestinal microbiota of a kestose-supplemented group (n=20) and a placebo group (n=16) before and after intake for 12 wk. The 5ar-level was significantly increased in the kestose-supplemented group (p=0.015), but not in the placebo group (p=0.379), indicating that kestose supplementation increased the 5ar-level in human intestinal microbiota. Our findings suggest that targeting functional gene levels could potentially be used to predict and understand the beneficial prebiotic effects associated with changes in gut microbiota.

The oral administration of pure monosaccharides is effective for improving intestinal function such as nutrient digestion and absorption. However, day-to-day diets tend not to include high purity monosaccharides for intestinal health. Honey possesses large amounts of monosaccharides including glucose and fructose in the same ratio. In this study, we have evaluated the nutritional properties of honey and examined the effects of its oral ingestion on the recovery of intestinal function in the total parenteral nutrition (TPN) rat model. It was observed that honey remarkably recovered the function of the small intestine including the villous morphology, nutrient digestion, and absorption capabilities. In particular, the expression of disaccharidase was significantly enhanced by the ingestion of honey after TPN treatment. Therefore, oral intake of honey is effective in recovering and maintaining small intestinal functions and can potentially be used as a supplement for promoting small intestinal function recovery.

Disaster and space environments are similar in that they are closed environment, with limited lifelines. Here, we examined the similarity between disaster food and space food, to explore interactive problem-solving of food support for disaster and space environments. The Japan Disaster Food Certification Standards (Japan Disaster Food Society) and the Japanese Space Food Certification Standards (Japan Aerospace Exploration Agency) requirements and certified products, which were posted on the websites as of June 16, 2021, were compared. Certified products were classified into “staple foods,” “main and/or side dishes,” “milk and dairy products,” “fruits,” “confectionery and favorite beverages,” “condiments,” “dietary supplements,” and “sets.” Certification standards involved six items for Japan Disaster Food and eight items for Japanese Space Food. Most standards were similar. Concretely, both standards demanded room temperature storage, tough packaging and hygiene management in facilities. Both emphasized habitual food and easy eating. However, the best-by date was ≥6 mo for Japan Disaster Food, but ≥1.5 y for Japanese Space Food. In addition, Japanese Space Food required noted nutritious, food hygienic, eatable in space, cookable by specific equipment, endurable pressure by launch, and domestically produced food. There were 171 and 47 products of Japan Disaster Food and Japanese Space Food, respectively. Staple foods (pregelatinized rice, etc.) and main and/or side dishes were commonest among Japan Disaster Foods and Japanese Space Foods, respectively. It is possible to utilize of Space Food as Disaster Food, but there are some issues that must be cleared before “utilization of Disaster Food as Space Food.”

The purpose of this study was to determine the effects of vitamin E supplementation on antioxidant, inflammatory status, and cell viability of peripheral blood mononuclear cells. Eighteen clinically healthy Japanese Black calves were used in this study. The peripheral blood mononuclear cells (PBMCs) were isolated from their venous blood. PBMCs were cultured with vitamin E (vitamin E group) or without vitamin E (control group), and stimulated with or without lipopolysaccharide (LPS). As a result, the total antioxidant capacities, which are the reducing power of components from Fe³⁺ to Fe ²⁺, in the cell culture supernatant with or without LPS stimulation were significantly higher in the vitamin E group than that in the control group (p<0.05 or p<0.01, respectively). Tumor necrosis factor alpha in the cell culture supernatant with LPS stimulation was significantly lower in the vitamin E group than in the control group (p<0.01). The viability of cells cultured with LPS stimulation was significantly higher in the vitamin E group than in the control group (p<0.05). These results suggested that vitamin E might be related to the antioxidant, anti-inflammatory, and cell viability of PBMCs obtained from calves.

Amino acids contribute to the taste of foods. Previous studies on the taste of amino acids focused mainly on α-amino acids, and therefore, the taste characteristics of amino acid derivatives remain unclear. In the present study, we targeted 6 different amino acid derivatives, β-alanine, citrulline, creatine, γ-aminobutyric acid, taurine, and ornithine, and evaluated their taste characteristics in a human sensory study. All tested amino acid derivatives showed multiple taste qualities; no derivatives had only a single taste quality. However, their taste intensities were relatively weak even at high concentrations. Given that the interactions between amino acid derivatives and nucleotide result in taste enhancements, we investigated the effect of inosine 5′-monophosphate (IMP) on the taste characteristics and found that the taste intensity of ornithine increased in the presence of IMP. This finding will be useful for understanding the role of amino acid derivatives as taste substances in daily foods.