Nutrition Research and Practice最新文献

Background/objectives: The increasing prevalence of overweight and obesity has become a significant global burden, with more than 40% of the global adult population attempting to lose weight. Previous studies on the impact of weight-control methods on mental health, especially among adolescents, are limited. Thus, this study aimed to investigate the association between various weight-control methods and depression among adolescents, with the goal of informing healthier weight management decisions and promoting effective methods.

Subjects/methods: This nationwide study utilized data from the Korea Youth Risk Behavior Web-based Survey, including a sample of 418,254 adolescents collected over 12 yrs (2007-2019). We conducted a weighted complex sample analysis to compare depression rates associated with specific weight-control methods, including exercise, fasting (≥ 24 h), eating less, taking prescription/non-prescription weight-loss medication, taking laxatives or diuretics, vomiting, one-food diet, taking oriental medicine, and diet foods.

Results: Of the 418,254 participants, 45.96% (192,246) were male. Among male participants, fasting (≥ 24 h; weighted odds ratio [wOR], 1.43; 95% confidence interval [CI], 1.36-1.51) and vomiting (wOR, 1.49; 95% CI, 1.35-1.66) were associated with an increased risk of depression. Among female participants, prescribed (wOR, 0.82; 95% CI, 0.74-0.90) and non-prescribed (wOR, 0.89; 95% CI, 0.82-0.97) weight-loss medication reduced the risk of depression. However, fasting (≥ 24 h; wOR, 1.47; 95% CI, 1.41-1.52) and vomiting (wOR, 1.45; 95% CI, 1.36-1.55) significantly increased the risk of depression.

Conclusion: The risk of depression varies depending on the weight-control method, with a consistent trend observed across both sexes. Methods such as vomiting, fasting, taking oriental medicine for weight loss, and consuming diet foods increased the risk of depression, while weight-loss medications were associated with reduced depression symptoms in females. These findings highlight the need for further research on weight-control medications and policies that support effective weight management while reducing depressive effects.

Background/objectives: The infiltration of macrophages into adipose tissue mediates chronic inflammation that is associated with insulin resistance in obesity. Although vitamin E is beneficial against insulin resistance, its impact on adipose tissue inflammation has not been elucidated. This study aims to investigate the effects of α-tocopherol and γ-tocopherol, major vitamin E isoforms, on the interaction between macrophages and adipocytes with regard to obesity-induced inflammation and insulin resistance.

Materials/methods: Hypertrophied 3T3-L1 adipocytes were cocultured with RAW 264.7 macrophages and treated with α-tocopherol or γ-tocopherol at 12.5, 25, and 50 µM. The inflammatory cytokines (monocyte chemoattractant protein-1, tumor necrosis factor-α, and interleukin-6) and free fatty acid (FFA) release were measured by assay kits, and nuclear factor-kappaB (NF-κB) and c-Jun NH₂ terminal kinase (JNK) signals were evaluated by immunoblotting. Glucose uptake was measured with a fluorescent glucose derivative.

Results: Treatment with α-tocopherol and γ-tocopherol restrained the coculture-induced increase in cytokines and FFA release. γ-Tocopherol exhibited greater suppression of inflammatory cytokines at 12.5 and 25 µM (P < 0.001). Both tocopherols inhibited NF-κB activation by limiting translocation of NF-κB (p65) to the nucleus, with γ-tocopherol showing a stronger effect compared to α-tocopherol. α-Tocopherol inhibited JNK phosphorylation at 50 μM, whereas γ-tocopherol did not. Furthermore, coculture with macrophages impaired glucose uptake in response to insulin, but both tocopherols restored insulin responsiveness (P < 0.01).

Conclusion: α-Tocopherol and γ-tocopherol effectively mitigate inflammation induced by adipocyte-macrophage interaction, thereby ameliorating coculture-induced insulin resistance. These findings suggest the therapeutic potential of tocopherols in managing obesity-related metabolic dysfunction.

Background/objectives: Appropriate vitamin D status improves bone health and chronic diseases; it has shown benefits during the coronavirus disease 2019 pandemic. Therefore, assessing vitamin D status is crucial. However, limited research on vitamin D intake among Koreans complicates understanding of its consumption. This study aimed to develop and validate a semi-quantitative food frequency questionnaire (FFQ) to assess vitamin D intake among Koreans.

Subjects/methods: A vitamin D FFQ was developed to include 31 vitamin D source foods from 8 food groups frequently consumed by Korean adults. The study included 152 women residing in a major city in South Korea. From September 2020 to August 2022, intake was surveyed using a 12-day dietary record (12-day DR) across 4 seasons, and 2 vitamin D FFQs were conducted approximately 9-11 months apart (FFQ1 and FFQ2). Reproducibility (FFQ1 vs. FFQ2) and validity (FFQ2 vs. 12-day DR) were verified using Spearman's rank correlation, weighted kappa coefficient, intraclass correlation, and Bland-Altman plots.

Results: The vitamin D intake of Korean women using the newly developed vitamin D FFQ was higher at FFQ1 (4.90 µg/day) and FFQ2 (4.58 µg/day) compared with the 12-day DR (4.07 µg/day). Additionally, the results for reproducibility and validity were demonstrated through the Spearman's rank correlation coefficient (reproducibility, 0.592; validity, 0.460), weighted kappa coefficient (reproducibility, 0.379; validity, 0.284), intraclass correlation coefficient (reproducibility, 0.599; validity, 0.543), and Bland-Altman plots (reproducibility index, 3.95%; validity index, 3.95%).

Conclusion: This study confirmed the newly developed vitamin D FFQ is reliable and valid for assessing vitamin D intake among Korean women. These results suggest the FFQ is an effective tool for dietary assessment, particularly in large-scale studies where year-round monitoring may not be feasible. Further validation in Korean men is crucial to enhance its applicability, enabling significant contributions to assessing vitamin D intake among Korean adults.

Background/objectives: As awareness of climate change increases, the relevance of environmental education in dietary choices gains prominence. Although diversely defined, food literacy (FL) is increasingly recognized as the ability to make food choices with an awareness of environmental sustainability. This study aims to conduct a pilot implementation and assess the effectiveness of a program developed to improve FL among university students.

Subjects/methods: The study spanned from August 2022 to February 2023, involving 92 participants (42 in the intervention group and 50 in the control group). Over 11 weeks, the program included cooking classes, local farm visits, and environmental impact lectures developed through extensive literature reviews and interviews with students and experts. FL was measured using a 33-item survey along with basic sociodemographic factors. After the intervention, both groups participated in qualitative interviews. All statistical analyses were carried out in Stata/SE version 17.0, and interview data were analyzed in Microsoft Excel using the framework analysis method.

Results: The FL scores of the intervention group improved significantly from an average of 65.8 to 69.6 points (P = 0.015), with notable gains in the socio-ecological domain in FL from 65.3 to 71.5 points (P < 0.001). A linear regression analysis comparing FL between the intervention and control groups found that only the knowledge items were marginally significant (P = 0.054), with no statistically significant difference in the practice aspect before and after the intervention (P = 0.657). The interviews revealed that the intervention group experienced broadened perspectives and heightened environmental consciousness, although translating these into practice was challenged by unchanged daily routines.

Conclusion: This pilot program effectively enhanced some aspects of FL-related knowledge of participants. High satisfaction among participants and no dropouts indicated its potential for scaling. Future programs will benefit from strategies that facilitate the transition from educational improvement to practical application.

Background/objectives: Quercetin (QT) is a plant flavonoid that offers health benefits owing to its various bioactive properties; however, as a hydrophobic substance, it has considerably low bioavailability. We previously demonstrated that QT nanoemulsion (QT+NE) formulated via oil-in-water nanoemulsification exhibited more effective cholesterol-lowering activity than ordinary QT in high cholesterol-fed rats. In this study, we investigated the effects of QT+NE on the regulation of skeletal muscle mitochondrial function in high-fat diet (HD)-fed mice.

Materials/methods: C57BL/6J mice were fed a normal chow diet (ND), HD (45% of calories from fat), or HD with 0.05% QT+NE or QT for 11 weeks. We analyzed sirtuin 1 (SIRT1) activation, mitochondrial changes, and the expression of genes involved in mitochondrial biogenesis in skeletal muscle.

Results: Body weight and body weight gain decreased in the QT+NE group compared with that in the HD group (P < 0.05), but not in the QT group. Epididymal adipose tissue weight decreased in both the QT and QT+NE groups (P < 0.05). Plasma lipid levels also improved in both the QT and QT+NE groups (P < 0.05). QT+NE intake upregulated the messenger RNA levels of SIRT1, peroxisome proliferator-activated receptor-γ coactivator 1-α, nuclear respiratory factor 1, and mitochondrial transcription factor A in skeletal muscle compared with HD intake alone (P < 0.05), whereas QT did not. In particular, SIRT1 activity was significantly increased in the QT+NE group compared with that in the QT group (P < 0.05). HD intake reduced mitochondrial DNA content compared with ND intake; nevertheless, QT+NE intake retained it (P < 0.05).

Conclusion: Collectively, our findings suggest that QT+NE may be beneficial in enhancing mitochondrial biogenesis in skeletal muscle of HD-fed mice, which may be associated with SIRT1 activation.

Background/objectives: The specific impact of different fruit and vegetable consumption categories on frailty is not completely understood. This study examined the relationships between the daily consumption of fruit and vegetables and frailty in a large general population.

Subjects/methods: This study used the data from the US National Health and Nutrition Examination Survey (2005-2020). Two intermittent 24-h dietary recalls were used to evaluate fruit and vegetable consumption. Frailty was assessed using the frailty index. Logistic regression, stratified analyses, and restricted cubic spline models were used to examine these associations.

Results: A higher daily intake of citrus, melons, and berries (odds ratio [OR], 0.77; 95% confidence interval [CI], 0.65-0.92), other fruit (OR, 0.74; 95% CI, 0.62-0.88), intact fruit (OR, 0.71; 95% CI, 0.60-0.84), dark-green vegetables (OR, 0.71; 95% CI, 0.60-0.83), and total vegetables (OR, 0.80; 95% CI, 0.66-0.96), along with a lower fruit juice intake (OR, 0.81; 95% CI, 0.69-0.96), were associated with a reduced risk of frailty in adults aged 18 yrs and older. Further analysis showed that the daily consumption of citrus melons and berries, other fruit, intact fruit, fruit juice, and tomatoes and tomato products were inversely associated with frailty in adults under 60 yrs and females. Dark green vegetables were inversely correlated with frailty in individuals aged 40-60 yrs and over 60 yrs, regardless of sex.

Conclusion: The daily consumption of most types of fruit, dark green vegetables, and tomatoes and tomato products may reduce the risk of frailty in American adults, particularly for individuals under 60 yrs of age and females.

Background/objectives: Sleep duration and diet quality are reportedly associated with the risk of diabetes. This study aimed to examine the risk of diabetes according to sleep duration and diet quality in middle-aged Koreans.

Subjects/methods: Using the Korea National Health and Nutrition Examination Survey 2019-2020, raw data from 2,934 participants aged 40-64 yrs (1,090 men and 1,844 women) who were not diagnosed with type 2 diabetes were analyzed. With a sleep duration of 7-7.9 h per night as the referent category, diet quality was assessed using the Korean Healthy Eating Index (KHEI), which comprises adequacy, moderation, and energy balance.

Results: The study results showed that individuals with a short sleep duration had significantly higher blood glucose (P = 0.034) and HbA1c levels (P < 0.001) than those had by individuals with a sleep duration of 7-7.9 h. Within the group with a sleep duration of 7-7.9 h, the lowest quintile of the KHEI score had a significantly higher risk of prediabetes than that had by the highest quintile of the KHEI score (Model 1: odds ratio [OR], 1.775; 95% confidence interval [CI], 1.072-2.939; P < 0.05 and Model 2: OR, 1.731; 95% CI, 1.040-2.882; P < 0.05).

Conclusion: Our findings suggest that achieving the sleep duration of 7-7.9 h and eating good diet are associated with the lowest risk of prediabetes. We recommend that the results of this study be used to educate adults aged 40-64 yrs on diet and lifestyle habits to prevent diabetes.

Background/objectives: There is growing interest in herbal medicines for managing age-related diseases, such as Alzheimer's and Parkinson's. Safflower seeds (Carthamus tinctorius L. seeds, CTS) and dandelions (Taraxacum coreanum, TC) are widely used to treat bone- or inflammation-related diseases in Oriental countries. This study investigated the protective effect of the CTS-TC combination on scopolamine (Sco)-induced memory deficits through inflammatory response and cholinergic function. Moreover, marker components such as serotonin, N-(p-coumaroyl) serotonin, N-feruloylserotonin, chlorogenic acid, and chicoric acid in the CTS-TC combination were analyzed for their potential benefits on memory function.

Materials/methods: Water extracts of CTS, TC, and the CTS-TC combination at various ratios (4:1, 1:1, and 1:4) (100 mg/kg) were orally administered to mice for 14 days. Sco (1 mg/kg) was intraperitoneally injected into the mice before each behavioral test. T-maze and novel object recognition tests were conducted to monitor behavioral changes after the treatment. Western blotting was performed to detect protein expression. In addition, the presence of 5 biomarkers, serotonin, N-(p-coumaroyl) serotonin, N-feruloylserotonin, chlorogenic acid, and chicoric acid, was analyzed using high-performance liquid chromatography (HPLC).

Results: Behavioral tests showed that the CTS-TC combination enhanced memory function in Sco-injected mice. Inflammation-related proteins (inducible nitric oxide synthase, cyclooxygenase-2, and glial fibrillary acidic protein) were downregulated after treatment with the CTS-TC combination. The acetylcholinesterase protein expression was also downregulated. HPLC analysis revealed that N-feruloylserotonin and chicoric acid were the predominant components, followed by N-(p-coumaroyl) serotonin, chlorogenic acid, and serotonin.

Conclusion: These findings suggest that the CTS-TC combination protects against Sco-induced memory deficits by inhibiting inflammatory responses and cholinergic dysfunction. N-feruloylserotonin and chicoric acid, along with N-(p-coumaroyl) serotonin, chlorogenic acid, and serotonin, might be biomarkers for the CTS-TC combination, and their effects on memory protection warrant further study.

Background/objectives: Atherosclerosis particularly due to high circulating level of low-density lipoprotein is a major cause of cardiovascular diseases. Ellagic acid is a natural polyphenolic compound rich in pomegranates and berries. Our previous study showed that ellagic acid improved functionality of reverse cholesterol transport in murine model of atherosclerosis. The aim of this study is to investigate whether ellagic acid inhibited inflammation-associated atherosclerotic plaque formation in cholesterol-fed apolipoprotein E (apoE)-knockout (KO) mice.

Materials/methods: Wild type mice and apoE-KO mice were fed a cholesterol-rich Paigen diet for 10 weeks to induce severe atherosclerosis. Concurrently, 10 mg/kg ellagic acid was orally administered to the apoE-KO mice. Plaque lesion formation and lipid deposition were examined by staining with hematoxylin and eosin, Sudan IV and oil red O.

Results: The plasma leukocyte profile of cholesterol-fed mice was not altered by apoE deficiency. Oral administration of ellagic acid attenuated plaque lesion formation and lipid deposition in the aorta tree of apoE-KO mice. Ellagic acid substantially reduced plasma levels of soluble vascular cell adhesion molecule and interferon-γ in Paigen diet-fed apoE-KO mice. When 10 mg/kg ellagic acid was administered to cholesterol-fed apoE-KO mice, the levels of CD68 and MCP-1 were strongly reduced in aorta vessels. The protein expression level of nitric oxide synthase-2 (NOS2) in the aorta was highly enhanced by supplementation of ellagic acid to apoE-KO mice, but the expression level of heme oxygenase-1 (HO-1) in the aorta was reduced. Furthermore, ellagic acid diminished the increased aorta expression of the inflammatory adhesion molecules in cholesterol-fed apoE-KO mice. The treatment of ellagic acid inhibited the scavenger receptor-B1 expression in the aorta of apoE-KO mice, while the cholesterol efflux-related transporters were not significantly changed.

Conclusion: These results suggest that ellagic acid may be an atheroprotective compound by attenuating apoE deficiency-induced vascular inflammation and reducing atherosclerotic plaque lesion formation.

Background/objectives: This study investigated the relationship between adolescent food-related lifestyles and food-related media use and eating behavior in Korea.

Subjects/methods: Participants were 392 Korean adolescents, ranging in age from 12 to 18, recruited via convenience sampling. They completed a self-report questionnaire survey consisting of questions about food-related lifestyle, food-related media use, food consumption behavior, food literacy, and nutrition quotient. Data analysis was conducted using SPSS 29.0. (IBM Co., Armonk, NY, USA).

Results: The factor analysis of food-related lifestyles identified four factors. Based on the cluster analysis results, participants were classified into three clusters reflecting different levels of interest: high interest in food, moderate interest in food, and low interest in food. The analysis revealed significant differences between groups in food-related liestyle factors (P < 0.05). Notably, the high-interest group demonstrated proactive engagement with food-related content, a willingness to explore diverse culinary experiences, and a conscientious consideration of nutritional labeling during food purchases. In contrast, the low-interest group reported tendencies toward overeating or succumbing to stimulating food consumption post-exposure to food-related content, coupled with a disregard for nutritional labeling when making food choices. A stronger inclination toward a food-related lifestyle was positively correlated with higher levels of food literacy and nutrition quotient.

Conclusion: This study proposes that the implementation of a nutrition education program using media could effectively promote a healthy diet among adolescents with a high level of interest in their dietary habits. For adolescents with low interest in their dietary habits, it suggests that introducing an education program with a primary focus on enhancing food literacy could be beneficial in fostering a healthy diet. Our research findings provide insight for the development of tailored nutritional education programs and establishment of effective nutrition policies.