Depression is a significant public health issue affecting relationships, work, and overall quality of life. In Japan, the number of patients with mood disorders, including depression, has increased significantly in recent years. Although malnutrition is known to worsen mental health and elevate the risk of depression and anxiety, the role of specific nutrients in preventing and managing depression remains unclear. This study investigated the association between nutrient intake, particularly vitamin K, and depressive symptoms, accounting for frailty in the Japanese population. Among the 607 participants in this study, 122 (20.1%) experienced depressive symptoms. Vitamin K was independently associated with depressive symptoms using a forward stepwise selection method. The relationship between vitamin K tertiles and depressive symptoms was assessed through multivariate logistic regression analysis. Adjusted for covariates (age, sex, frailty, education level, living status, exercise habits, energy intake, and alcohol consumption), the odds ratios (ORs) for depressive symptoms were significantly lower in tertile 3 compared to tertile 1. The ORs (95% confidence interval, p-value) for tertile 2 and tertile 3 were 0.64 (0.38–1.07, 0.087) and 0.48 (0.28–0.82, 0.008), respectively. Lower vitamin K intake was independently associated with depressive symptoms. Further research is necessary to confirm the role of vitamin K in preventing depressive symptoms.

Vitamin D deficiency is mainly caused by lack of sun exposure and low intake. Data on its prevalence and optimal sun exposure in Indonesian infants, particularly aged 7–12 mo, are lacking. This randomized controlled study aimed to evaluate the effect of sun exposure on serum 25(OH)D concentration in infants in Semarang, Indonesia. Conducted between February and May 2019, the study involved 109 infants who met inclusion criteria (no congenital/chronic illness, parental consent) and excluded those with moderate to severe malnutrition, non-yellow or brown skin tone, clinically significant vitamin D deficiency, or those receiving vitamin D supplements. Intervention group received sun exposure on 50% of body surface for 5 min, three times weekly between 10:00 am and 2:00 pm for 2 mo. Serum 25(OH)D concentration were measured pre- and post-intervention, and food recall was used to assess daily intake in both groups. Pre-intervention, there was no significant difference in serum 25(OH)D concentration between intervention (mean 39.1±14.9 ng/mL) and control group (mean 38.6±15.4 ng/mL). However, post-intervention results showed a statistically significant increase in serum 25(OH)D concentration in intervention group (mean 47.9±21.9 ng/mL) compared to control group (mean 36.6±13.7 ng/mL; p=0.005). Notably, there was no significant difference in dietary vitamin D intake between two groups throughout the study. This study concluded that brief and consistent sun exposure significantly increased serum 25(OH)D concentration in infants, suggesting that sun exposure is an effective natural strategy to improve vitamin D status in this age group.

Japanese-style diet has been reported to be associated with decreased risk of cardiovascular disease. However, no study has examined the association between a Japanese-style diet and LOX-index, which reflects the progression of atherosclerosis and is a predictive biomarker of cardiovascular disease. We examined the cross-sectional association between a Japanese-style diet assessed using the 12-component Japanese diet index (JDI12) score, which is a modified version of the original Japanese Diet Index, and LOX-index in Japanese municipal workers. Participants were 338 workers (166 men and 172 women aged 19–71 y) without a history of serious disease. Dietary intake was assessed using a validated brief self-administered diet history questionnaire. The JDI12 was characterized by a high intake of rice, miso soup, fish and shellfish, green and yellow vegetables, seaweeds, pickled vegetables, green tea, soybeans and soybean foods, fruits, and mushrooms and low intakes of beef and pork and coffee. LOX-index was calculated by multiplying serum concentrations of the soluble form of lectin-like oxidized LDL receptor-1 (LOX-1) by those of LOX-1 ligands containing apolipoprotein B. Multiple regression analysis was used to estimate the geometric mean of LOX-index according to tertile of JDI12 score. The JDI12 score was not associated with LOX-index after adjustment for covariates. Geometric means (95% confidence interval) of LOX-index for the lowest through highest tertile of JDI12 score were 590 (532–654), 592 (506–693), and 618 (557–687) (p for trend=0.55). Our results suggest that a Japanese-style diet as assessed by JDI12 score was not associated with LOX-index among Japanese municipal workers.

Thiols, as a class of organic compounds containing sulfhydryl, play important roles in antioxidant, cytoprotective and signaling activities. This study aimed to investigate thiol/disulfide metabolite homeostasis in children with diabetic ketoacidosis (DKA) and their correlation with disease severity and renal impairment. Children with type 1 diabetes mellitus complicated with ketoacidosis from June 2022 to December 2024 were selected for this study. The metabolite levels of thiols and disulfides were measured by collecting blood samples from the children and testing them using a highly automated spectrophotometric assay. Clinical data, including blood glucose, blood ketones, blood gas analysis, and renal function indicators, were collected from the children to assess the severity of the disease and renal impairment. Seventy-two children with DKA (19 mild, 25 moderate, and 28 severe cases), were included. Native thiols were elevated with disease exacerbation, while total thiols and disulfides did not change significantly. Homeostatic index 1 and index 3 differed among the three groups. Reduced renal function was observed in 34 children with DKA, who also had decreased natural thiols, total thiol, and homeostatic index 3. Elevated native thiols were protective factors for disease exacerbation (OR 0.980, 95% CI 0.960–1.000) and renal function decline (OR 0.970, 95% CI 0.950–0.990) in children with DKA. Thiol/disulfide metabolite homeostasis in children with DKA is strongly associated with disease severity and renal impairment. Reduced native thiols are associated with more severe DKA and renal impairment.

This study quantified phytosterol contents in cereals, vegetables, fruits, legumes, nuts/seeds, and plant oils commonly consumed in Korea and estimated daily phytosterol intake using nationally representative dietary data. Phytosterol concentrations varied substantially across food groups, with the highest levels observed in plant oils (rapeseed oil, 311.63 mg/100 g; sesame oil, 302.72 mg/100 g) and seeds (sesame seeds, 159.59 mg/100 g). The average daily intake among Koreans was 84.52 mg/d. Cereals contributed 35.84 mg/d, followed by vegetables (20.40 mg/d) and oils (12.60 mg/d). Major contributors included rice (15.90 mg/d), baechu kimchi (4.60 mg/d), tofu (3.17 mg/d), and soybean oil (6.23 mg/d). In international comparisons, Korea had the lowest intake among the countries examined (China, 392.30 mg/d; Spain, 275.40 mg/d; the Netherlands, 285.00 mg/d; Finland, 238.00 mg/d; Indonesia, 223.80 mg/d; Poland, 282.97 mg/d; and the United Kingdom, 163.00 mg/d). The relatively low intake appears to reflect dietary patterns characterized by high cereal consumption and limited use of plant oils. Given that habitual intake remains far below the 2 g/d level associated with cholesterol-lowering effects, these findings provide essential baseline data for evaluating phytosterol exposure in the Korean population and for developing culturally appropriate nutritional strategies.

Food processing and cooking methods that involve high-temperature heating (such as roasting) alter the composition of raw food materials. Even polyphenols, which are generally considered thermally stable, undergo changes in their chemical structure during roasting. This study investigated the roasting reaction of catechin, a functional polyphenol, at a temperature of approximately 200ºC and found that it enhanced xanthine oxidase inhibitory activity. Purification and separation of the products derived from the catechin roasting reaction revealed two types of moderately active compounds: dimeric products with a linkage between the C and A rings, and an aurone-like benzofuran product. Additionally, several fractions containing oligomeric products were identified as highly active fractions. These results suggest that catechin enhances xanthine oxidase inhibitory activity by transforming into dimeric, aurone-type, and probably oligomeric products.

This study aimed to evaluate sex-specific associations between food intake and frailty using cross-sectional data from 786 participants (317 men, 469 women) aged 65–101 y from the baseline survey of the Kyotango cohort study. In multivariate-adjusted models, men in the highest quartile of bean intake and vegetable intake other than green and yellow vegetables (other vegetables) had 78% and 83% lower risks of frailty, respectively, than those in the lowest quartile. Similarly, women in the highest quartile of other vegetable intake had 76% lower risks of frailty than those in the lowest quartile. Hierarchical cluster analysis revealed that Cluster 3, characterized by frequent intake of seafood, milk, and plant-based foods, including tuber vegetables, beans, green and yellow vegetables, other vegetables, and fruits, was associated with a reduced risk of frailty. In conclusion, plant-based dietary patterns were associated with a lower prevalence of frailty in men and women. Within this pattern, women consumed more seafood, suggesting a sex-specific feature of the dietary profile.

Energy intake assessed using the food frequency questionnaire for Japanese athletes (FFQJA) was evaluated with the doubly labeled water method. The subjects (n=10) were recruited from a male track and field team in one university. The average total energy intake assessed using the FFQJA was 2,662 (standard deviation: 445) kcal, and the average total energy expenditure assessed using the doubly labeled water method was 3,149 (337) kcal. The FFQJA estimate of total energy intake was 486 (897) kcal lower than the total energy expenditure corrected for changes in body weight. A percentage difference between total energy intake and corrected total energy expenditure was −10.3% on average. No significant difference was found between energy intake and corrected energy expenditure. However, Kendall’s τ_b and weighted Kappa suggested poor agreement at the individual level. Bland–Altman plot analysis suggested that there was no significant relation between differences in total energy intake and corrected total energy expenditure and average of total energy intake and corrected total energy expenditure (r=−0.493, p=0.147). Because the present study examined only a small number of participants and all of whom were male track and field athletes from the same team, future studies will be needed to clarify the generalizability of these findings.

This study investigated the effect of epigallocatechin-3-gallate (EGCG), a major polyphenol in green tea, on the cecal levels of microbial metabolites of tryptophan (Trp) in rats. Rats were fed either a control diet or a diet containing 0.25% (w/w) EGCG for 1 wk. The results showed that dietary EGCG treatment increased the concentration of indole-3-lactic acid while decreasing indole-3-propionic acid in the cecal contents compared to the control group. Furthermore, analysis of fecal microbial composition by 16S rRNA gene sequencing revealed that EGCG supplementation reduced the relative abundance of the genus Clostridium. This study provides fundamental insights into the role of EGCG in modulating the production of biologically active Trp metabolites.