Nutrition Research and Practice最新文献

Background/objectives: This study aimed to elucidate the mechanisms by which Vaccinium oldhamii water extract (VOW) modulates inflammation and insulin sensitivity in 3T3-L1 cells and RAW 264.7 macrophages.

Materials/methods: VOW's effects on inflammation and insulin resistance were assessed in macrophages and adipocytes. To investigate crosstalk between macrophages and adipocytes, RAW 264.7 cells were cultured in the upper chamber while mature 3T3-L1 cells were cultured in the lower chamber. The medium was collected to measure glucose uptake.

Results: Our findings indicate that VOW significantly reduces the protein expression of inflammatory cytokines, including extracellular signal-regulated kinase, Jun N-terminal kinase, mitogen-activated protein kinase p38, and nuclear factor kappa-light-chain-enhancer of activated B cells, which are upregulated by lipopolysaccharide and inhibit reactive oxygen species expression. In mature 3T3-L1 cells with type 2 diabetes mellitus, VOW treatment enhances the protein expression of phosphatidylinositol 3-kinase, Ak strain transforming, and insulin receptor substrate, which are critical for insulin sensitivity, and facilitates the translocation of glucose transporter type 4 from the cytosol to the plasma membrane. Additionally, treatment of 3T3-L1 cells with macrophage-conditioned media results in decreased insulin sensitivity, whereas VOW treatment restores insulin signaling protein expression in a dose-dependent manner.

Conclusion: Our study suggests that VOW modulates the interplay between increased insulin sensitivity and inflammation.

Background/objectives: The present study aimed to analyze the effect of food literacy on the short-term and long-term healthy eating intentions of convenience store consumers using the Extended Theory of Planned Behavior (ETPB) framework.

Subjects/methods: A cross-sectional online survey was conducted in South Korea in September 2023. A total of 397 Korean participants were recruited through convenience sampling. The independent variables included food literacy, attitudes, subjective norms, and perceived behavioral control. The χ² tests, t-tests, correlation analysis, and hierarchical regression were performed, with statistical significance set at P < 0.05.

Results: Adolescents showed significantly higher food literacy than adults (P < 0.01). In contrast, adults demonstrated higher scores in attitude (P < 0.01), subjective norm (P < 0.05), perceived behavioral control (P < 0.01), and short-term (P < 0.001) and long-term healthy eating intentions (P < 0.001). When food literacy was included as a variable in the hierarchical regression analysis, the explanatory power for short-term and long-term healthy eating intentions increased by 1.7% and 5.3%, respectively (P < 0.001).

Conclusion: The study highlights the need for customized nutrition education and continuous, systematic education on eating habits to enhance food literacy.

Background/objectives: Colorectal cancer (CRC) is a malignancy that occurs in the colon or rectum and ranks as the second leading cause of cancer-related fatalities globally. Numerous epidemiological studies have revealed a distinct difference in CRC between sexes. Specifically, a lower incidence rate and delayed onset in females than in males. β-Carotene (BC), a provitamin A carotenoid, elicits antioxidant effects; however, the potential sex-specific differences in its anti-colon cancer effect are unknown. This study aims to compare the effect of BC on inflammation between sexes in azoxymethane/dextran sulfate sodium (AOM/DSS)-induced early CRC.

Materials/methods: The AOM/DSS mouse model was established. In early CRC, systemic changes were assessed using the disease activity index (DAI), serum proinflammatory cytokine levels, estradiol, and retinol concentrations. Local changes were evaluated using colon length, tumor counts, proinflammatory cytokines, and estrogen receptor (ER) α expression in the colon.

Results: In early CRC-induced systemic changes, females had higher DAI scores and lower serum estradiol levels than males. DAI scores were decreased in both sexes, however, serum cytokine levels were reduced by BC supplementation only in females. In the early CRC model, the systemic disease activity in females was higher than that in males. Serum retinol concentrations decreased to a greater extent in female AOM/DSS-induced CRC mice than in their male counterparts. In terms of local changes, the colon was shorter and the ERα expression was increased in females.

Conclusion: In early CRC, higher disease activity and specific changes, such as increased DAI scores and reduced serum estradiol in females than in males. BC supplementation could effectively reduce DAI scores and systemic inflammation in both sexes. Notably, serum cytokine levels decreased only in females.

Background/objectives: Accurate estimation of nutrient intake from food consumption requires reliable food composition data. However, since nutrient content changes during cooking, the application of raw ingredient composition may lead to overestimation, particularly for energy and fat in meat dishes. In this study, the suitability of applying cooked food codes for meat dishes to improve the validity of recipe-based nutrient content estimation was evaluated.

Materials/methods: Pork (thin-sliced and thick-cut belly and shoulder butt) and beef (tenderloin, loin, rib meat, and brisket point) were examined for cooking yield after grilling and their nutrient contents were estimated. Each cut was portioned to 100 g of raw meat and cooked in triplicate. Nutrient content was calculated using both raw and cooked meat codes from the Korean Standard Food Composition Table, and differences in energy, fat, and protein content were compared.

Results: When grilled under standardized conditions, the average cooking yield was approximately 65% for pork and 80% for beef (P < 0.0001). Thin slices of pork belly had a lower yield (62.6%) than thicker cuts (68.0%), while beef brisket point had the lowest yield among beef cuts (63.6%). Applying cooked meat codes and measured cooking yields resulted in overall decreases in energy (-10% to -50%) and fat (-20% to -60%) content, with slight increase in protein (up to +34%, P < 0.0001). For beef tenderloin, additional comparisons using matched raw and grilled data from the United States Department of Agriculture SR Legacy Database showed smaller percent differences in energy, fat, and protein than those obtained from the Korean database.

Conclusion: Incorporating measured cooking yields and corresponding cooked meat codes into recipe-based databases can improve the accuracy of nutrient intake estimation. The development of nutrient databases that reflect differences in cooking conditions-including temperature, duration, and doneness-should be prioritized to enhance the validity of national dietary surveys.

Background/objectives: The food frequency questionnaire (FFQ) is a commonly used tool for assessing the usual diet of groups and individuals. This study developed a chatbot-based mobile FFQ, embedded within KakaoTalk, Korea's most popular mobile instant messenger. This study compared the energy and nutrient intake reported by participants using a chatbot versus a paper-based FFQ.

Subjects/methods: This study included 95 participants (50 men and 45 women, aged 24-79 yrs) who underwent gastroscopy or colonoscopy for cancer screening at Dongguk University Ilsan Hospital between April and August 2022. The participants completed both the chatbot and paper-based FFQs within a 3-mon period. The comparability of the chatbot-based FFQ with traditional paper-based FFQ was examined by comparing the log-transformed intakes of energy and nutrients using Pearson correlation coefficients. The Cohen's Kappa coefficients, Bland-Altman plots, and cross-classification percent agreement were used to evaluate the compatibility.

Results: The Pearson correlation coefficients of energy and energy-adjusted nutrients ranged from 0.74 (niacin) to 0.90 (vitamin A), with a median coefficient of 0.85. The Cohen kappa coefficients varied from 0.42 (niacin) to 0.64 (n-6 fatty acid). The Bland-Altman plots suggested that most of the data points fell between the lower and upper limits of agreement, and 88% to 98% of the participants were classified into the same or adjacent quartiles for energy-adjusted nutrients.

Conclusion: These findings indicate good comparability between chatbot- and paper-based FFQs. A chatbot-based mobile FFQ can provide comparable dietary intake rankings, making it a viable tool for evaluating the associations between diet and various disease risks in longitudinal studies.

Background/objectives: Coffee consumption is associated with metabolic syndrome (MetS), but the findings have been inconsistent because of residual confounding. This study investigated the relationship between coffee consumption and MetS and its components using Mendelian randomization (MR) with genetic instrumental variables (IVs).

Subjects/methods: Coffee consumption was calculated from a food-frequency questionnaire using the 12-mon frequency and portion size, with cups converted to grams (2.7 g/cup) in the Korean Genome and Epidemiology Study-Health Examinees cohort (n = 58,144) for genetic instrument selection. MetS was defined by the National Cholesterol Education Program Adult Treatment Panel III guidelines in the Ansan and Ansung cohort (n = 5,351) for the outcome estimation. Genome-wide association analysis (GWAS) for coffee consumption (g/day) was conducted using linear regression, and logistic regression was used for MetS and its components. IVs were single-nucleotide polymorphisms associated with coffee consumption at genome-wide significance (P < 5 × 10^-6) from GWAS after linkage disequilibrium clumping (r² < 0.05 within ± 500 kb). MR analyses of the association between coffee consumption and MetS and its components were conducted using 5 approaches (inverse variance weighted [IVW], MR-Egger, weighted median, weighted mode, and simple mode). Sensitivity analyses were conducted using Cochran's Q and the horizontal pleiotropy test.

Results: IVW indicated a negative association with MetS in males (odds ratio, 0.702; 95% confidence interval, 0.613-0.805). In females, MetS and its components had no association (P < 0.05). Cochran's Q detected heterogeneity in females for elevated waist circumference, and MR-pleiotropy residual sum and outlier analysis identified outliers, but the results remained unchanged.

Conclusion: This MR study revealed sex-specific causal relationships between coffee consumption and MetS in Korean adults, suggesting protection against MetS and its components in males.

Background/objectives: Aging is often accompanied by chronic oxidative stress, contributing to the progression of metabolic disorders. A previous study reported that supplementation with collagen tripeptide (CTP) inhibits fatty liver and lipid hypertrophy, but the mechanism is unclear.

Materials/methods: This study examined the effects of 12-week CTP supplementation on oxidative stress, insulin resistance, and adenosine monophosphate-activated protein kinase (AMPK) α activation, key factors in metabolic disorders in aged mice. Thirty-eight male C57BL/6J mice (58 weeks old) were assigned to 4 groups: aging control, 0.03% Gly-Pro-Hyp, 0.9% CTP, and 0.9% granulated collagen tripeptide (gCTP) supplementation. A group of young mice (YC, n = 8) served as the positive control.

Results: The results showed that CTP and gCTP enhance antioxidant capacity by reducing thiobarbituric acid reactive substances and H₂O₂ and improving the antioxidant enzyme activities, including superoxide dismutase and glutathione peroxidase. CTP also improved insulin sensitivity by increasing the expression of insulin receptors and glucose transporters in the liver and white adipose tissue. Furthermore, CTP and gCTP improved energy metabolism and mitochondrial function via AMPKα activation.

Conclusion: CTP supplementation is a promising intervention to mitigate comorbidities in older adults, such as obesity and fatty liver disease. CTP and gCTP supplementation may serve as functional ingredients to improve energy metabolism and mitochondrial function. Their potential to reduce oxidative stress, improve insulin resistance, and enhance AMPKα expression supports their use in managing obesity and fatty liver disease, particularly in older adults.

Background/objectives: There has been a notable lack of effort to evaluate the nutritional status of persons with disabilities objectively and identify their nutritional challenges. This study aimed to assess whether nutritional inadequacies and imbalances are more pronounced in persons with disabilities compared to those without, using data from the 6th Korea National Health and Nutrition Examination Survey (2013).

Subjects/methods: The participants were classified into 387 persons with disabilities and 4,909 without disabilities. The 15 types of disabilities were categorized into 5 groups, and disability severity was classified as severe or mild. Nutrient intake and nutritional status were assessed using 24-h dietary recall data.

Results: Compared to persons without disabilities, those with disabilities had significantly lower nutrient adequacy ratios for 8 of 10 nutrients, the exceptions being vitamins B1 and C (all P < 0.05). The likelihood of low overall nutrient adequacy based on the mean adequacy ratio was significantly higher among persons with disabilities (odds ratio [OR], 1.50; 95% confidence interval [CI], 1.11-2.04), with particularly elevated odds for those with severe, visual, and internal organ disabilities. Persons with severe disabilities had higher odds of consuming a diet with low nutrient density (OR, 1.59; 95% CI, 1.05-2.40) and of experiencing nutritional deficiency (OR, 2.21; 95% CI, 1.02-4.75) than those without disabilities. Additionally, the odds of consuming a high-carbohydrate diet, with > 70% of daily energy intake from carbohydrates, was 3.63-fold higher (95% CI, 1.40-9.42) among persons with mental disabilities.

Conclusion: Persons with disabilities faced significant nutritional inadequacies and imbalances compared to those without disabilities. Targeted nutrition interventions and disability-inclusive nutrition policies and practices are urgently needed to reduce these disparities.

Background/objectives: This research is objective to examine the synergistic hypocholesterolemic effects of n-3 highly unsaturated fatty acids (HUFA) combined with pro- or post-biotics on dyslipidemia caused by chronic mild stress (CMS) through modulating biosynthesis and clearance of cholesterol.

Materials/methods: Rats were assigned into 7 random groups, each containing 8 rats: n-3 HUFA deficient diet without CMS, CMS with n-3 HUFA deficient diet, pro-biotics, post-biotics, n-3 HUFA, n-3 HUFA with pro-biotics, and n-3 HUFA with post-biotics. The induction of CMS occurred over 5 weeks during the 12-week dietary supplementation period.

Results: The n-3 HUFA, pro-biotics, and post-biotics ameliorated dyslipidemia caused by CMS and downregulated cholesterol biosynthesis through decreasing sterol regulatory element-binding protein-2 (biotics, P < 0.001; N3, P < 0.001; synergistic, P = 0.014) and 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (biotics, P < 0.001; N3, P < 0.001; synergistic, P < 0.001). Moreover, they upregulated cholesterol clearance by increasing low-density lipoprotein-cholesterol reuptake through proprotein convertase subtilisin/kexin type 9 (biotics, P < 0.001; N3, P < 0.001; synergistic, P = 0.036) and bile acids biosynthesis through cytochrome p450 family 7 subfamily A member 1 (biotics, P < 0.001; N3, P < 0.001; synergistic, P < 0.001) and cytochrome p450 family 27 subfamily A member 1 (biotics, P < 0.001; N3, P < 0.001; synergistic, P = 0.001).

Conclusion: Therefore, n-3 HUFA with pro-biotics or post-biotics exert synergistic hypocholesterolemic effects on dyslipidemia induced by CMS through regulating biosynthesis and cholesterol clearance.

Background/objectives: Regulating the postprandial glucose levels is crucial for preventing the progression of prediabetes to diabetes. This study examined the effects of a diabetes-specific nutrition formula (DSNF) on the postprandial plasma glucose, serum insulin, and serum c-peptide levels in individuals with prediabetes.

Subjects/methods: An open-label, crossover clinical trial was conducted to compare the effects of the DSNF versus standard oral nutritional supplement (ONS) on glycemic control. Fifteen subjects with prediabetes were enrolled and received the DSNF on the first visit and standard ONS on the second. The postprandial plasma glucose, serum insulin, and serum c-peptide incremental area under the curve (iAUC), as well as the incremental maximal concentration (iC_max) and the maximum concentration (C_max), were measured after each intervention. Statistical comparisons between DSNF and standard ONS were conducted using a Wilcoxon's signed-rank test.

Results: After consuming the DSNF, the iAUC of the postprandial glucose level was significantly low compared to the standard ONS (1,683.49 ± 911.65 vs. 4,455.92 ± 1,658.77, P < 0.0001). Similarly, the serum insulin iAUC (2,017.33 ± 987.64 vs. 2,570.59 ± 1,201.09, P = 0.0181) and c-peptide iAUC (274.17 ± 116.12 vs. 491.18 ± 123.90, P < 0.0001) decreased significantly after DSNF administration compared to the standard ONS.

Conclusions: The consumption of DSNF significantly improved the postprandial glucose, insulin, and c-peptide responses compared to the standard ONS.

Trial registration: Clinical Research Information Service Identifier: KCT0008904.