Nutrition Research and Practice最新文献

Background/objectives: An illustrated questionnaire, the Healthy Eating Practice Questionnaire (HEPQ), was developed and validated to assess healthy eating practices among Korean preschool children.

Subjects/methods: The development process consisted of 4 phases: (1) item generation based on a literature review and focus group interviews, (2) item refinement through expert consultation, (3) illustration design, and (4) validation. One hundred and eighty-seven child-parent pairs and 24 teachers participated in the validation study. The reliability was examined using test-retest analysis, and the validity was assessed by comparing the children's self-reports with those of their parents and teachers. The level of agreement was determined using the percentage agreement, kappa statistics, and intraclass correlation coefficient (ICC).

Results: The final 30-item questionnaire consisted of 4 domains: food preferences, eating behaviors, hand/oral hygiene practices, and nutrition knowledge. Most items showed a percentage agreement above 60% and kappa coefficients exceeding 0.5 in test-retest analysis, indicating acceptable consistency. The child-caregiver agreement was moderate to substantial, with kappa values generally above 0.4. The domain-level ICCs indicated good reliability (ICC = 0.49-0.83) and validity (ICC = 0.33-0.77) across all domains and subgroups. The comparisons by age showed that 4-yr-olds provided valid and reliable responses comparable to 5-yr-olds. The parents and teachers confirmed that the illustrated format was easy for the children to understand and complete independently.

Conclusion: The HEPQ showed satisfactory reliability and validity for assessing healthy eating practices among preschool children. The illustrated format enhances comprehension and engagement, supporting its applicability for research and nutrition education in daycare settings.

Background/objectives: This study examined the effect of calcium (Ca), fucoidan, and chitooligosaccharide supplementation alone and in combination on bone mineral density (BMD), bone metabolism, and Ca balance in ovariectomized (OVX) rats.

Materials/methods: Forty-eight female Wistar rats (6 weeks) were used in this study; among them, 40 rats were OVX, and the rest of the rats were sham-operated (sham). The sham group and one OVX group were fed a standard diet (AIN-96, Ca 0.5%), and the remaining OVX groups received either a fucoidan-supplemented diet (fucoidan 0.05%; OVX-Fu), a chitooligosaccharide-supplemented diet (chitooligosaccharide 0.5%; OVX-Chito), a seaweed Ca-supplemented diet (Ca 1.5%; OVX-Ca), or a fucoidan, chitooligosaccharide and seaweed Ca-supplemented diet (fucoidan 0.05%, chitooligosaccharide 0.5%, Ca 1.5%; OVX-CaFuChito) for 12 weeks.

Results: The OVX-CaFuChito group had the highest feed intake, but had a significantly lower final body weight than the other groups in OVX rats. The Ca retention was significantly higher in the OVX-Ca and OVX-CaFuChito groups than in all the other groups (P < 0.001). There was no effect of the treatments on bone mineral content and BMD at any site. When analyzing BMD divided by final body weight, the combined supplementation group had significantly higher BMDs at the lumbar spine, femur, and tibia compared to the OVX group; in contrast, individual supplementation did not show significant improvement in the BMD at any site in OVX rats.

Conclusion: These results suggest that only the combined supplementation of Ca, fucoidan, and chitooligosaccharides may have a beneficial effect on preserving BMD along with suppressing postmenopausal weight gain.

Background/objectives: This study examined whether the intake pattern of dietary and supplementary vitamin C differs according to the sufficiency of fruit and vegetable (FV) intake and assessed the risk of vitamin C insufficiency according to FV sufficiency and vitamin C supplement use.

Subjects/methods: Data from 10,464 adults aged ≥ 19 yrs from the 2019-2021 Korea National Health and Nutrition Examination Survey (KNHANES) were analyzed. The participants were categorized into an FV-sufficiency (FVS; ≥ 500 g/day) and FV-insufficiency (FVINS; < 500 g/day) groups. The vitamin C intake from diet, supplements, and major food sources was examined.

Results: Approximately 19.6% of young adults, 41.5% of middle-aged adults, and 39.6% of older adults met the recommended intake of FV. Most participants in the FVS group consumed more than 90 mg of dietary vitamin C (90% of the recommended nutrient intake [RNI]), whereas most in the FVINS group consumed less than 50 mg (50% of the RNI). Even among the FVS group, the proportion meeting the RNI ranged from 27% to 37%. In the FVINS group with adequate vitamin C intake, vitamin C was derived predominantly from sugar-sweetened beverages, fruit juice products, and meat. The participants who took vitamin C supplements had a lower risk of vitamin C insufficiency than non-users, regardless of the FV intake status.

Conclusion: Although the prevalence of vitamin C insufficiency was high, regardless of FV sufficiency, supplementation allowed the FVS and FVINS groups to meet the recommended levels. Nevertheless, the quality of dietary sources remains a concern, with a reliance on less healthy options such as sugar-sweetened beverages and fruit juice products, particularly among young adults. These findings highlight the importance of promoting natural food sources like FV for better diet quality.

Background/objectives: Interest in health improvement through mobile application (app)-based dietary interventions is increasing, and related research is on the rise. Mobile app usage as a means of dietary intervention is currently underwhelming. Therefore, this study aimed to provide dietary recommendations to patients through a mobile app and analyze the impact of their consumption on the improvement of health indicators.

Subjects/methods: This pilot intervention study evaluated the changes in disease-related indicator levels following a 2-week dietary intervention in patients (n = 15; mean age = 71 years) with type 2 diabetes, hypertension, and obesity from January to February 2024 at Chonnam National University in Korea. We calculated participants' daily caloric requirements based on the information they had entered into the mobile application and also provided disease-specific dietary recommendations. Moreover, we measured their body characteristics and collected blood samples before and after the intervention to analyze changes in disease-related biomarkers and metabolites.

Results: The body mass index (P = 0.028), systolic blood pressure (P = 0.038), and grip strength (left) (P = 0.009) values of 14 participants significantly improved following the dietary intervention. Additionally, their fasting blood glucose, high-sensitivity C-reactive protein, malondialdehyde, adiponectin, and leptin levels also improved. In the serum metabolite analysis, participants with hypertension exhibited a significant decrease in circulating lactate (P = 0.03) and trimethylamine N-oxide (P = 0.06) levels after following the mobile app-based dietary recommendations.

Conclusion: Although a pilot, this mobile app-based dietary intervention yielded marked improvements across several disease indicators, suggesting that its advancement may help prevent and manage chronic diseases.

Background/objectives: Steamed ginger extract (GGE03) has been proposed as a complementary treatment for osteoarthritis (OA). On the other hand, the efficacy and mechanism are incompletely understood. This study examined the anti-osteoarthritic effects of GGE03 in monosodium iodoacetate (MIA)-induced OA Sprague-Dawley (SD) rats.

Materials/methods: The rats were divided into the following groups: normal control group (NC); OA control group (OC); OA+30, 50, or 100 mg/kg body weight (BW)/day GGE03 group (O+G30, O+G50, or O+G100); OA+150 mg/kg BW/day methyl sulfonyl methane (MSM, positive control group (O+M). The SD rats were given GGE03 or MSM orally for 5 weeks. MIA was injected intra-articularly into the knee joints on day 15 to induce OA. The exercise performance test, pain behavior test, micro-computed tomography, histological examination, and immunofluorescence staining were performed on the knee joint. The inflammatory mediators, cytokines, and matrix metalloproteinase (MMP) mRNA expression were measured in the knee joint synovial fluid.

Results: The OC group had significantly shorter exercise times to exhaustion and withdrawal threshold according to the von Frey test, more severe knee joint swelling and subchondral bone erosion than the NC group, and reduced type II collagen and aggrecan expression in the articular cartilage. The OC group showed a significantly higher mRNA expression of inflammatory mediators, cytokines, and MMPs than the NC group. In OA rats, GGE03 administration reduced knee swelling and cartilage degradation and increased type II collagen and aggrecan expression in the articular cartilage. GGE03 administration reduced the expression of inducible nitric oxide synthase, cyclooxygenase-2, 5-lipoxygenase, interleukin (IL)-1β, IL-6, tumor necrosis factor-α, MMP-2, MMP-3, MMP-9, and MMP-13 in the synovia of the knee joints.

Conclusion: GGE03 administration is a useful supplementary agent for anti-OA treatment.

Background/objectives: Hyperlipidemia is a lipid metabolic disease and statins are mainly used to treat hyperlipidemia in the clinics. However, resistance to statin therapy is a limitation. Artemisia selengensis Turcz (AST) is a vegetable that has had poorly studied effects on hyperlipidemia.

Materials/methods: We prepare the AST as a source of various health-promoting nutrients. First, using the root, stem, and leaves of AST were separated and demonstrated its effect on lipid-lowering indices in vitro. Next, we studied the effect of AST leaf in vivo. AST leaf (100 mg/kg BW/d) was used to treat 4-week-old high-fat diet induced male Wistar rats (n = 12) for 21 days.

Results: We have observed that anti-hyperlipidemia index were significantly improved by AST leaf in vitro experiment. Moreover, it is significantly ameliorated the serum lipid profile and reduced total cholesterol after 21 days of treatment. mRNA expression of the metabolism-related genes LDLR, CYP7A1, HMGCR, SREBP2, and ABCA1 was also significantly increased. Moreover, we also estimated the feces bile acid level, which increased significantly following treatment with AST in the leaves. Furthermore, phenol and flavonoid levels were significantly greater in the AST leaves (ASTL) than in the roots and stems, as revealed by the untargeted metabolomics analysis.

Conclusion: The findings revealed that the phenols and flavonoids in ASTL may have contributed to their ability to effectively facilitate hyperlipidemia through the liver-intestinal axis in vivo.

Background/objectives: This study aimed to perform a nutritional risk assessment in Korean adults by estimating the usual intake of energy and nutrients from foods, including dietary supplement (DS) intake, and assessing the prevalence of excessive and inadequate intake.

Subjects/methods: The usual intake for adults aged 19 to 69 years was estimated using the National Cancer Institute method, applying the within- and between-person variance from the 2009 Korea National Health and Nutrition Examination Survey (KNHANES) to one-day dietary recall data from the 2019-2021 KNHANES. The usual intake from foods only was calculated using this approach. The DS intake was then added to estimate the total nutrient intake. Nutrient adequacy was assessed according to gender and age using the 2020 Korean Dietary Reference Intakes.

Results: The distribution of the usual intake estimates differed significantly from the one-day values. In particular, the one-day intake underestimated the prevalence of excessive sodium intake (68.5%) compared to the usual intake (83.8%), while inadequate protein intake prevalence was overestimated considerably (21.6% vs. 5.6%). Men showed a higher prevalence of excessive energy, protein, fat, and sodium intake, while women showed a higher prevalence of inadequate intake, particularly for iron (45.5%), even after accounting for DS intake. Micronutrient inadequacy was more common in younger adults, whereas adults aged 30 years and older showed a higher prevalence of excessive intake with DS use. Although DSs helped reduce the prevalence of inadequate intake (e.g., vitamin A: 74.8% to 61.2%), they also slightly increased the prevalence of excessive intake in some nutrients.

Conclusion: Estimating the usual nutrient intake offers a more robust and realistic nutritional risk assessment than using the one-day dietary recall data as it stands. This study revealed disparities in nutritional intake according to gender and age, and highlighted the dual role of DSs. Public health strategies should support food-based nutrient adequacy before promoting DS use and provide targeted interventions for vulnerable groups.

Background/objectives: Fatigue is closely associated with an impaired mitochondrial function, oxidative stress, and inefficient energy metabolism, all contributing to reduced physical performance. Nutritional strategies targeting mitochondrial biogenesis and antioxidant defense may help alleviate fatigue and enhance endurance. This study examined the anti-fatigue and antioxidant effects of an amino acid (AA)-epigallocatechin gallate (EGCG) mixture comprised of 3 AAs (cysteine [Cys], glutamine [Gln], and leucine [Leu]) and EGCG on mitochondrial biogenesis, oxidative stress mitigation, and physical performance enhancement.

Materials/methods: C2C12 myoblasts were treated to assess mitochondrial biogenesis-related gene expression and oxidative stress markers. Animal studies measured the swimming endurance, glycogen, adenosine triphosphate (ATP), and serum parameters. A pilot clinical trial evaluated the blood glucose, lactate, and serum enzyme levels post-exercise.

Results: In cellular experiments, a 1:1:3 ratio of the AA mixture (Cys, Gln, and Leu) with EGCG enhanced mitochondrial biogenesis-related gene expression (AMP-activated protein kinase, sirtuin 1, and peroxisome proliferator-activated receptor gamma coactivator 1α [PGC-1α]) and reduced the oxidative stress markers (reactive oxygen species and malondialdehyde [MDA]). Animal studies revealed significant increases in swimming endurance, elevated glycogen and ATP levels, and reduced serum fatigue markers (creatine phosphokinase, lactate dehydrogenase, and blood nitrogen). Furthermore, nuclear factor erythroid 2-related factor 2 (NRF2) and PGC-1α expression was significantly upregulated in the gastrocnemius muscle, supporting enhanced mitochondrial function. In addition, the antioxidant effects were observed with reduced MDA levels in liver tissue. Clinical trial data showed improved blood lactate clearance and higher post-exercise blood glucose levels in the AA-EGCG group compared to the placebo group.

Conclusion: The AA-EGCG mixture enhances mitochondrial biogenesis and antioxidant capacity by activating the NRF2 and PGC-1α pathways, improving physical performance and reducing fatigue. This study highlights its potential as a supplement for managing fatigue and enhancing endurance.

Background/objectives: Iodine is an essential mineral that is critical for humans, as inadequate and excessive intake can lead to adverse health outcomes. Data on dietary iodine intake and adequacy among Koreans remain limited. This study aimed to estimate the dietary iodine intake of Koreans, assess the adequacy of intake, and examine the primary dietary sources of iodine in the Korean population.

Subjects/methods: This study analyzed data from 18,895 participants aged ≥ 1 yr obtained from the Korea National Health and Nutrition Examination Survey (KNHANES) 2019-2021. Dietary iodine intake was calculated using a newly constructed iodine database applied to KNHANES data. Intake levels were compared against the sex- and age-specific reference values outlined in the Korean Dietary Reference Intakes 2020. Insufficient intake was below the estimated average requirement (EAR), while excessive intake was above the tolerable upper intake level (UL).

Results: The median iodine intake of Koreans aged ≥ 1 yr was 114 µg/d, corresponding to 123% of the EAR. Approximately 4 in 10 Koreans did not meet the EAR, one exceeded the UL, and only 5 had adequate iodine intake. Excessive intake was most prevalent among children under 12 yrs of age. Two-thirds of iodine intake came from plant-based foods, with seaweed, eggs, fish, milk, and grains identified as the major dietary contributors.

Conclusion: Koreans' median dietary iodine intake appears adequate; however, a significant proportion exhibit insufficient or excessive intake. Further research is needed to estimate usual iodine intake and develop strategies for addressing problematic iodine intake.

Background/objectives: Atherosclerosis is a chronic inflammatory disease characterized by the buildup of low-density lipoprotein (LDL) within arterial walls, triggering inflammation and vascular constriction. Vitamin D has been shown to suppress T cell proliferation, reduce inflammatory responses, and promote the development of regulatory T cells (Tregs). However, its role in modulating T cell function in atherosclerotic models is not fully understood. This study examined the effects of vitamin D supplementation on T cell activation and Treg development in Ldlr ^-/- mice.

Materials/methods: C57BL/6J mice (CON) were fed a control diet (10% kcal fat), while B6.129S7-Ldlr^tm1Her /J mice (ATH) were fed a Western diet (40% kcal fat + 0.15% w/w cholesterol). Both diets contained 1,000 or 10,000 IU vitamin D/kg diet (vDC or vDS, respectively) for 16 weeks. Purified T cells were stimulated using plate-bound anti-CD3ε/soluble anti-CD28, then cultured for 48 h. Immune cell populations in the spleen, cytokine production by T cells, and the expression of key genes and proteins involved in Treg function, T cell receptor (TCR) signaling, and hypoxia were assessed.

Results: The expression of TCR signaling genes (Lck and Zap70) and the Treg transcription factor forkhead box P3 (Foxp3) were significantly higher in ATH compared to CON. Additionally, interleukin (IL)-10 levels were higher in ATH than in CON, while IL-17 and IL-2 levels did not show significant differences between the groups. Expression of hypoxia-inducible factor (Hif1a) was also higher in ATH compared to CON. Overall, vitamin D supplementation had a notable effect on Zap70 expression, which was lower in vDS compared to vDC.

Conclusion: The higher Foxp3 expression and IL-10 production observed in the ATH suggest the activation of compensatory mechanisms to counteract inflammation. Enhanced TCR signaling in the ATH, likely associated with oxygen depletion due to heightened energy demand, may have contributed to the elevated Hif1a expression. The lower Zap70 expression in the vDS suggests that vitamin D supplementation suppresses T cell activation.