Journal of nutritional science and vitaminology最新文献

Niacin is a cofactor in many biological reactions related to energy metabolism, redox reactions, DNA repair and longevity. Although it has been considered that increasing energy expenditure increases NAD consumption, little study has directly demonstrated the effect of exercise on niacin nutritional status. We have recently established the niacin insufficient model mice using kynurenine 3-monooxygenase knock out (KMO^-/-) mice with niacin-limited diet, which lack the de novo NAD synthesis pathway from tryptophan. To evaluate the effects of chronic endurance exercise on niacin nutritional status, 4 wk old KMO^-/- mice were fed 4 or 30 mg/kg nicotinic acid containing diets, and forced to swim in a running water pool every other day for 35 d. The swim-exercised mice fed 4 mg/kg nicotinic acid diet showed lower body weight gain and niacin nutritional markers such as liver and blood NAD, and urine nicotinamide metabolites than the sedentary mice. These animals did not show any difference in the NAD synthesis, NAD salvage and nicotinamide catabolic pathways. Chronic endurance exercise failed to affect any indices in the mice fed the 30 mg/kg nicotinic acid diet. When the diet was exchanged the 4 mg/kg for 30 mg/kg nicotinic acid diet to the mice showed chronic endurance exercise-induced growth retardation, their body weight rapidly increased. These results show that chronic endurance exercise impairs niacin nutritional status in the niacin insufficient mice, and enough niacin intake can prevent this impairment. Our findings also suggest that chronic endurance exercise increases niacin requirement by increase of NAD consumption.

The purpose of this study was to examine whether 4 wk of daily ingestion of milk fat globule membrane (MFGM) combined with exercise training improves physical performance-muscle strength, agility and muscle power-in healthy young adults. The study was designed as a randomized, double-blind, and placebo-controlled trial. Twenty healthy young adults received either an MFGM powder containing 1.6 g of fat and 160 mg of sphingomyelin or an isocaloric placebo powder daily throughout 4 wk of power or agility training. Physical performance tests and body composition measurements were conducted before and after the 4-wk intervention. Ingestion of MFGM did not affect isometric or isokinetic muscle strength, but it was associated with a greater increase in vertical jump peak power compared with placebo. There were no significant changes in body weight or lean body mass during the intervention period in either group, and no significant differences between groups. We conclude that daily MFGM supplementation combined with exercise training has the potential to improve physical performance in young adults; however, further studies with larger sample sizes should be conducted to obtain more evidence supporting achievement of improved physical performance through MFGM supplementation.

D-Allulose has blood glucose suppression effects in both animal and clinical studies. The mechanism mediating glucose suppression in animals is controlled by several actions including the inhibition of sucrase. To investigate the dose-response effects of D-allulose with a sucrose beverage on glucose tolerance and insulin levels using Thai volunteers. This was a prospective, randomized, double-blinded, crossover study. Subjects had five oral sucrose tolerance tests (OSTT) with escalating doses of D-allulose (0, 2.5, 5, 7.5 or 10 g) with a 50 g sucrose beverage in a random order once a week for five consecutive weeks. The five drinks were consumed in a random order; the order being blinded for both subjects and investigators. Blood samples were drawn immediately before consumption and at 30, 60, 90 and 120 min after consumption of the study product for measurement of plasma glucose and insulin levels. Thirty healthy subjects (11 men and 19 women) completed the study. The peak postprandial glucose (PePPG) and insulin levels (PePPI) were lower when D-allulose was added in a dose-dependent manner. The lowest plasma glucose and insulin levels occurred at 120 min after OSTT in all five products and they were raised when D-allulose was added in a dose-dependent manner. D-Allulose has a suppression response on glucose and insulin shown by the decrease in postprandial plasma glucose and insulin levels following the addition of D-allulose to sucrose in a dose-dependent manner. The more D-allulose added, the less marked the glucose and insulin response occurred.

Chronic kidney disease (CKD) poses a major global public health challenge. The World Health Organization's data shows that CKD affects about 10% of the world's population, particularly in low- and middle-income countries. Due to limited access to diagnosis and treatment, CKD has become the 12th leading cause of death worldwide. The advanced stage of CKD can lead to kidney failure, which is clinically referred to as end-stage renal disease (ESRD). In such cases, patients can only sustain life through dialysis or kidney transplantation. However, the long-term affordability of these treatments remains low. Moreover, the effectiveness of kidney transplantation is modest, posing a significant treatment barrier in resource-limited settings, and significantly impacting patient survival. To address this issue, we suggest using dietary supplementation of the trace element zinc to impede CKD development and prolong patient survival.

Prevalence of hip fractures is on the rise and is associated with high mortality, especially in aging patients. Vitamin D is routinely recommended for bone health in general population. Our study explores the potential association between low levels (≤20 ng/mL) of vitamin D and mortality in hip fracture patients. Systematic search was done for studies that were published from inception until May 10, 2023, and that report a possible correlation between low vitamin D levels and mortality in patients with hip fractures. A random-effects model was used to assess the effects of normal vitamin D levels on mortality, subgroup analyses were conducted to assess the link between low levels of vitamin D and geographic location of the study and its impact on the recovery process. In 575 identified studies, 18 met the inclusion criteria. A strong connection between low serum levels of vitamin D (<20 ng/mL) and mortality (hazard ratio (HR): 2.29, p<0.001). Further analysis indicated that insufficient (20 to 30 ng/mL) and sufficient (>30 ng/mL) levels of vitamin D levels did not have a significant association with the mortality (HR: 1.10, p=0.12), and (HR: 1.04, p=0.50). As shown by subgroup analysis vitamin D deficiency significantly correlated with mortality in studies conducted in Europe (HR: 2.4). Our results clearly demonstrate that vitamin D deficiency is associated with higher risk of mortality in hip fracture patients. Additional analyses demonstrate that insufficient and sufficient levels of vitamin D were not significantly associated with mortality outcomes in hip fracture patients.

Ascorbic acid is essential for human health. As this vitamin is water-soluble, it cannot be stored in the body for a long time and is easily excreted in urine; therefore, it is necessary to ingest it in sufficient amounts every day. The fact that apples retain ascorbic acid in human bodies are known; however, this has not been experimentally demonstrated/documented. In this study, to clarify the effect of apple juice ingestion on the urinary excretion of ascorbic acid, we compared urinary ascorbic acid excretion in healthy women administered ascorbic acid alone or with apple juice. The experimental design was an unblinded randomized crossover study. Subjects ingested ascorbic acid in apple juice or ascorbic acid with water. Urine was collected after ingestion, and urinary ascorbic acid was measured. When ascorbic acid was ingested with apple juice, urinary excretion of ascorbic acid was significantly suppressed compared to when ascorbic acid was ingested alone. This suggests that apple juice intake can help retain ascorbic acid in the body.

By comparing germ-free mice and specific pathogen-free mice, we recently demonstrated that the presence of gut commensals upregulates microRNA-200 family members in lamina propria leukocytes (LPL) of the murine large intestine. The present study tested whether the consumption of 1-kestose (KES), an indigestible oligosaccharide that alters gut microbiota composition, influences the microRNA expression in the LPL. Supplementation of KES (4%) in drinking water for 2 wk increased the levels of miR-182-5p, -205-5p, -290a-5p, miR-200 family members (miR-141-3p, -200a-3p, -200b-3p, -200c-3p, and -429-3p) as well as miR-192/215 family members (miR-192-5p, -194-5p, and -215-5p) as determined by microarray analysis in large intestinal LPL of C57BL/6 mice. Quantitative reverse transcription-PCR further confirmed the increase in miR-192-5p, -194-5p, -200a-3p, -200b-3p, -200c-3p, -205-5p, and 215-5p. KES consumption significantly increased Bifidobacterium pseudolongum in the cecal contents. In a separate experiment, intragastric administration of B. pseudolongum (10⁹ CFU/d) for 7 d increased the levels of miR-182-5p, -194-5p, and -200a-3p and tended to increase the levels of miR-200b-3p, -215-5p, and -429-3p. These results suggest that dietary KES influences miRNA expression in the large intestinal LPL, which may be associated with the increased population of B. pseudolongum.

The present paper first proposes a method for ensuring the safety of commercial herbal supplements, termed the suggested daily intake-based safety evaluation (SDI-based safety evaluation). This new method was inspired as a backward analog of the acceptable daily intake (ADI) derivation from the no observed adverse effect level (NOAEL), the basis of food additive risk analysis; namely, rats are dosed with individual herbal supplement products at the SDI for human use multiplied by 100 (the usual uncertainty factor value) per body weight for 8 d. The primary endpoint is the sign of adverse effects on liver, especially gene expression of cytochrome P450 (CYP) isoforms. The proposed method was then applied to three butterbur (Petasites hybridus) products without pyrrolizidine alkaloids but lacking clear safety information. Results showed that two oily products markedly enhanced the mRNA expression of CYP2B (>10-fold) and moderately enhanced that of CYP3A1 (<4-fold) with liver enlargement. These products also caused the renal accumulation of alpha 2-microglobulin. One powdery product showed no significant effect on liver and kidney. The large difference in effects of products was due to the difference in chemical composition revealed by liquid chromatography-mass spectroscopy. The oily and the powdery products required attention in terms of safety and effectiveness, respectively. Finally, the results from the SDI-based safety evaluation of butterbur and other herbal supplement products were grouped into four categories and cautionary notes were discussed. The SDI-based safety evaluation of their products by herbal supplement operators would contribute to safe and secure use by consumers.

Aldehyde oxidase (AO) plays an important role in the metabolism of antitumor and antiviral drugs, including methotrexate, favipiravir, and acyclovir. The consumption of blueberry fruits or their extracts, which contain large amounts of anthocyanins, has recently increased. The intake of large amounts of anthocyanins occurs through the frequent consumption of blueberries or their functional foods, which may result in unwanted interactions between anthocyanins and medicinal drugs. Therefore, the present study examined the inhibition of AO by anthocyanins, anthocyanidins, and blueberry extracts in human liver cytosol using a HPLC assay. A comparison of the 50% inhibitory concentration (IC₅₀) values of the test compounds showed that anthocyanidins slightly suppressed AO activity, whereas the inhibitory effects of anthocyanins and blueberry extracts were negligible. The inhibitory activities of the anthocyanins tested were approximately 60- to 130-fold weaker than that of the positive control menadione and were almost negligible. Furthermore, they were approximately 2,000-fold less potent than that of raloxifene, a typical AO inhibitor, and, thus, unlikely to interfere with drug metabolism by AO. In addition, since the plasma concentrations of anthocyanins after their administration were generally lower than the IC₅₀ level, the inhibition of AO substrate metabolism by anthocyanins does not appear to be severe.

Protein is an essential nutrient that plays several roles in the maintenance of the human body. A high-protein diet is also known to play an important role in weight management in obese individuals and in maintaining muscle strength in the elderly. However, over-consumption of protein can have negative effects on health, including deterioration of the intestinal environment by the production of amino acid metabolites such as phenols. Interest in the regulation of the intestinal environment to maintain health has gained attention recently. Resistant maltodextrin (RMD) is a prebiotic dietary fiber. Therefore, we investigated whether RMD suppressed the production of amino acid metabolites through intestinal regulation in rats. Wistar rats were fed either an AIN-93G diet or a modified AIN-93G diet containing 5% tyrosine. RMD (2.5% or 5.0%) was provided with drinking water. The rats were fed these diets and water ad libitum for 3 wk. Urine was collected overnight, after which serum, liver, kidneys, and the whole cecum were collected from rats under anesthesia with isoflurane for analysis of phenols and microbiota. RMD decreased the cecal, serum, and urinary levels of phenols, especially phenol. Moreover, the relative abundance of intestinal Romboutsia ilealis showed a significant correlation with the cecal phenols levels, and RMD decreased the abundance of this species. Thus, RMD may suppress phenols production and decrease serum phenols levels by altering the intestinal environment in rats.