Nutrition Research and Practice最新文献

Background/objectives: Our study aimed to investigate the association of food group intake and the quality of diet with the risk of loss of muscle mass in Korean baby boomers using a large-scale national cohort data.

Subjects/methods: The study included 1,280 Korean baby boomers (609 men and 671 women) who were born between 1955 and 1963 and who participated in the Korean Genome and Epidemiology Study from 2001 to 2018. A validated semi-quantitative food frequency questionnaire was used to assess dietary intake. The Korean Healthy Eating Index (K-HEI) and the Mediterranean-Type Diet scores helped to evaluate the quality of the diet. Bioelectrical impedance analysis at baseline and during follow-up visits was used to measure the total muscle mass. Muscle loss was defined as a ≥ 5% decrease in total muscle mass over 2 yrs. This prospective cohort study had a mean follow-up duration of 12.7 yrs. Cox proportional hazards model was used to estimate the hazard ratio for muscle loss on the basis of the levels of dietary variables.

Results: In men, high grain intake was significantly associated with an increased risk of muscle loss (P for trend = 0.023). In women, a high intake of dairy products was associated with a reduced risk of muscle loss (P for trend = 0.021). Additionally, higher fruit intake and K-HEI scores were inversely associated with muscle loss when adjusted only for age and total energy intake.

Conclusion: Our study demonstrates gender-specific associations of diet with the loss of muscle mass in the Korean baby boomers. Although high grain intake may increase the risk of loss of muscle mass in men, high dairy intake may provide protective effects in women. These findings emphasize the need for targeted dietary strategies to prevent age-related muscle loss.

Background/objectives: Dietary choices play a crucial role in individual health, with food literacy being a key factor influencing these choices. Therefore, this study examined the relationship between food literacy and healthy eating intentions among adults in Shandong Province, China.

Subjects/methods: Cross-sectional data were collected from 492 adults in Shandong Province, China, between October 2023 and January 2024, using a validated questionnaire that incorporated constructs from the theory of planned behavior (TPB) and food literacy (FL). The FL levels were categorized using the original 4-level classification, and multiple linear regression analyses were conducted, controlling for confounders to examine the associations across these levels.

Results: The scores for the behavioral intentions varied according to sociodemographic factors, such as education levels and physical activity. As the FL levels increased, the scores on all TPB constructs increased significantly, consistently, and linearly (all, P < 0.001, P for trend < 0.001). After adjusting for confounding variables, the perceived behavioral control remained a consistent and significant positive predictor of the behavioral intentions across all levels of FL (P < 0.001). Nevertheless, the subjective norms (P < 0.001) were positively associated with healthy eating intentions only among individuals in the lowest rank of FL, whereas the attitudes (P = 0.019) were positively associated with the behavioral intentions only among those in the highest rank.

Conclusion: Individuals with lower FL levels were likelier to have their behavioral intentions influenced by others. In contrast, those with higher FL levels tended to hold more positive attitudes toward the benefits of healthy eating and showed greater willingness to seek detailed dietary information. These findings underscore the importance of developing targeted interventions to enhance FL and promote healthy eating intentions among adults in Shandong Province.

Background/objectives: This study analyzed 10-yrs trends in dietary vitamin D intake and its food sources among Koreans.

Subjects/methods: This study included 61,734 individuals (≥ 3 yrs) from the 2013-2022 Korea National Health and Nutrition Examination Surveys. Daily vitamin D intake was assessed based on 24-h recall data. 10-yrs trends in 1) vitamin D intake, 2) vitamin D intake relative to the adequate intake (AI) of 2020 Dietary Reference Intakes for Koreans, and 3) proportions of individuals whose vitamin D intake below and above AI were analyzed using a complex sampling general linear model. Changes in food sources of vitamin D was also determined.

Results: Vitamin D intake significantly decreased over 10 yrs with 3.2 μg/d in 2013 and 2.9 μg/d in 2022 (P-trend = 0.003) among Koreans. A significant decreasing trend was observed in males (3.6 μg/d in 2013 to 3.1 μg/d in 2022; P-trend = 0.002) but not in females. The average percentage of vitamin D intake relative to the AI decreased from 34.1% in 2013 to 30.9% in 2022 (P-trend = 0.003). The proportion of individuals whose vitamin D intake was below the AI increased from 93% in 2013 to 95% in 2022 (P-trend < 0.001). In 2022, the main food sources were eggs, squid, soy milk, salmon, mackerel, and pork, with increased contributions from eggs, soy milk, and pork than that in 2013.

Conclusion: Vitamin D intake among Koreans has declined significantly over the past decade. Developing effective dietary guidelines considering sex and age is essential to improve vitamin D intake in this population.

Background/objectives: The Korean population traditionally consumes more iodine-rich seaweeds than Western populations due to dietary culture and geographical location. However, the association between excessive iodine intake and thyroid disease remains controversial. This study aimed to evaluate the association between iodine intake and thyroid disease using the largest-scale Korean cohort data.

Subjects/methods: This study utilized data from 190,524 participants in the Korean Genome and Epidemiology Study. Iodine intakes were assessed using a validated semi-quantitative food frequency questionnaire. Iodine intake was classified into quintiles, and the association between iodine intake and the prevalence of thyroid disease was evaluated using multivariate logistic regression analysis.

Results: Of the 190,524 participants, 8,387 (4.40%) were diagnosed with thyroid diseases by a physician. In the total population, higher iodine intake was not associated with an increased risk of thyroid disease after adjusting for confounding variables. Additionally, the odds ratio for the highest iodine intake group compared to the lowest iodine intake group was 0.89 (95% confidence interval [CI], 0.71-1.11; P for trend = 0.7434) in men and 0.92 (95% CI, 0.85-1.00; P for trend = 0.2286) in women.

Conclusion: Excessive iodine consumption was not associated with thyroid disease in Korean adults. Further longitudinal studies are required to assess the long-term effects of iodine intake on thyroid disease.

Backgrounds/objectives: This study examined the anti-osteoarthritic effects of a Curcuma longa Linn ethanol extract (CLE), standardized to 500 mg/g of curcuminoids, in monosodium iodoacetate (MIA)-induced osteoarthritis (OA) Sprague-Dawley (SD) rats.

Materials/methods: The rats were divided into a normal control group (NC), OA control group (OC), OA +10, 20, 30, or 50 mg/kg body weight (BW)/day CLE-administered group (O+CL10, O+CL20, O+CL30, or O+CL50), and OA+150 mg/kg BW/day methyl sulfonyl methane (MSM, positive control)-administered group (O+M). The rats were given oral doses of CLE or MSM for 5 weeks, with an intra-articular injection of MIA into their knee joints on the 15th day to induce OA. 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 showed more severe knee joint swelling and subchondral bone erosion than the NC group, and aggrecan and type II collagen expression in the articular cartilage was reduced. The OC group exhibited lower mRNA expression of inflammatory mediators, cytokines, and MMPs than the NC group. In OA-induced rats, the oral administration of the CLE reduced knee swelling and cartilage degradation and increased aggrecan and type II collagen expression in the articular cartilage. CLE 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 knee joints. In particular, these levels reached the same as the positive control group, the O+M group.

Conclusion: The CLE had potent anti-OA effects in MIA-induced OA rats by suppressing the expression of inflammatory mediators, cytokines, and MMPs, alleviating cartilage degradation. Hence, the CLE is a potential functional food ingredient that can prevent and improve OA.

Background/objectives: Telomere length is influenced by inflammation, insulin resistance, and hyperinsulinemia, which can be modulated by dietary factors. Nevertheless, it is still uncertain if diets with greater insulinemic or inflammatory potential are linked to shorter telomere length.

Subjects/methods: This cross-sectional study analyzed the data from the National Health and Nutrition Examination Survey in the US. A total of 6,981 individuals were included, with an average age of 46.87 ± 0.36 yrs, and a female-to-male ratio of 1.12:1. Diet was obtained using 24-h recall. Three empirical dietary indices were developed, including the Empirical Dietary Inflammatory Pattern (EDIP), which identifies foods predictive of inflammation markers such as C-reactive protein and leukocyte count; the Empirical Dietary Index for Insulin Resistance (EDIR), which assesses insulin resistance via homeostatic model assessment; and the Empirical Dietary Index for Hyperinsulinemia (EDIH), which relates to hyperinsulinemia indicators including insulin and C-peptide. Relative telomere length (RTL) was measured by quantitative polymerase chain reaction. Percentage change (%), odds ratio (OR), and their 95% confidence intervals (CIs) were evaluated using linear and ordinal logistic regression, respectively.

Results: EDIR (per 1 - SD increase, percentage change = -0.99%, 95% CI, -1.83%, -0.15%, P _trend = 0.022; OR, 1.08, 95% CI, 1.01, 1.16, P _trend = 0.018) and EDIH (percentage change = -1.03%, 95% CI, -1.94%, -0.11%, P _trend = 0.030; OR, 1.07, 95% CI, 1.00, 1.15, P _trend = 0.047) were associated with shorter RTL. EDIP showed a negative association with telomeres in ordinal logistic regression (OR, 1.07, 95% CI, 1.00, 1.15, P _trend = 0.038), and this inverse association was more pronounced among participants with a light or vigorous activity in both regression (P _interaction = 0.003; P _interaction < 0.001).

Conclusion: Diets high in inflammation or insulinemic potential are associated with shorter RTL. The impact of EDIP is greater in individuals engaged in light or vigorous activity.

Background/objectives: Cadmium (Cd) can cross the placental barrier and affect fetal development. Dietary exposure is a primary source of Cd intake. However, studies examining the relationships between food intake, placental Cd concentration, and offspring growth remain limited, especially in Asian populations. This study aimed to identify foods and cooking methods that contribute to placental Cd concentration and assess the association between placental Cd concentration and infant growth.

Subjects/methods: This study analyzed 72 non-smoking pregnant women and their placentas. Food intake during late pregnancy was assessed using a food frequency questionnaire and categorized based on main ingredients and cooking methods. Placental Cd concentration was measured using an inductively coupled plasma mass spectrometer. Neonatal anthropometrics were obtained from medical records, while 1-yr anthropometrics were collected through interviews.

Results: Placental Cd concentration was not associated with intakes of foods when categorized according to main ingredients; however, positive associations with the intake of boiled and deep-fried foods were observed (β = 0.350 and 0.739, respectively; both P < 0.01). A positive trend was observed between placental Cd concentration and placental efficiency (β: 0.101, P = 0.07), while placental Cd concentration was negatively associated with birth weight and length in female infants (β = -19.55 and -1.358, respectively; P < 0.05). No significant associations were found between p[Cd] and 1-year growth indicators.

Conclusion: Placental Cd concentration may be associated with the consumption of boiled and deep-fried foods during late pregnancy, rather than intake of a certain food group categorized by main ingredient. The observed trend of increased placental efficiency despite lower birth weight and length in female infants suggests that the placenta may function as a barrier to Cd sex-specifically, potentially mitigating its effects on offspring development.

The lack of a standardized classification system poses challenges for accurately assessing ultra-processed food (UPF) consumption in Korea. This scoping review compared the UPF consumption levels reported in Korean studies and analyzed the discrepancies to highlight the need for a unified UPF classification system tailored to Korea. Four online databases were searched to identify studies conducted in Korea. From 147 papers, 20 papers that examined UPFs as the main variables were selected and reviewed. Their consumption levels are reported. Ninety percent of the papers were cross-sectional studies, while 10% were prospective cohort studies. Most studies (72%) measured UPF consumption using the 24-h dietary recall (24HR), while 28% used food frequency questionnaires (FFQs). The most popular topic (65%) was the association between UPF consumption and health outcomes, with obesity-related outcomes being examined most frequently. A wide range of UPF consumption was observed: from 4.9% to 32.8% of total energy intake. The estimates from food-based FFQs were the lowest compared to those from the dish-based FFQs or 24HR. Significant variations in UPF consumption levels were observed across dietary assessment methods, researchers, and data sources. This scoping review highlights the need for an objective and standardized UPF classification system, developed through collaboration among researchers, to minimize the potential misclassification issues when estimating UPF consumption or examining its associations with the health outcomes in Korea. Establishing a "UPF Working Group" could serve as an effective starting point for this initiative, and it is expected to attract participation from more researchers interested in UPF studies.

Background/objectives: An adequate postprandial glycemic response (PPGR) is crucial for glycemic control in diabetes. However, predicting glycemic responses to mixed meals is challenging, as they are influenced by various nutritional factors. Moreover, despite the increasing demand for convenience foods, the validation of their impact on the PPGR remains insufficient. Therefore, we investigated the impact of consuming cooked rice, a ready meal developed for persons with diabetes, on the PPGR.

Subjects/methods: Twenty-seven healthy adults participated in this study, and they consumed 6 test products over a 10-h fasting or non-fasting state. The test products included one type of regular cooked rice (OTOKI Cooked Rice & Curry Sauce [Curry-R]) and 5 types of cooked rice developed for persons with diabetes (Cooked Rice & Curry Sauce [Curry-D], Spicy Sauce with Pork [Spicy pork-D], Bulgogi [Bulgogi-D], Soybean Paste Sauce [Soybean-D], and Jjajang Sauce [Jjajang-D]). Blood glucose levels were measured for 2 h after test-product consumption using a continuous glucose monitoring device. Incremental area under the curve (iAUC), Peak_max, total AUC (tAUC), and glycemic load (GL) values were calculated to determine the PPGR.

Results: In the fasting state, Spicy pork-D, Bulgogi-D, and Soybean-D significantly reduced the iAUC and GL, with Spicy pork-D and Soybean-D also lowering Peak_max compared with Curry-R. In the non-fasting state, Spicy pork-D, Bulgogi-D, Soybean-D, and Jjajang-D yielded significantly lower tAUC and Peak_max values.

Conclusion: Cooked rice products developed for persons with diabetes potentially reduce the PPGR in healthy individuals under both fasting and non-fasting states. Nutritional adjustments, such as modifications of protein, fat, dietary fiber, and sugar content in convenience foods, can moderate the PPGR.

Background/objectives: This study aimed to assess the nutritional quality of plant-based school meals by comparing plant-based and regular menus in Seoul's elementary schools.

Materials/methods: Nutrient information for plant-based and regular menus (Monday-Friday) was collected from school websites during a designated week in June 2023 when plant-based meals were offered. The analysis included 1,526 menus (321 plant-based, 1,205 regular) from 313 of 608 schools. Average energy and nutrient content were calculated for both menu types, along with the proportion of schools meeting the nutritional standards for school meals provided by the Ministry of Education in South Korea. Statistical analyses included χ² tests, Fisher's exact test, and t-tests (α = 0.05).

Results: Analysis of energy and nutrient content in both menu types revealed that all nutrients, except vitamin C, met or exceeded the nutritional standards for school meals. However, plant-based menus provided significantly lower levels of energy, protein, fat, thiamine, and vitamin C, and higher levels of carbohydrates, calcium, and iron compared to regular menus. While the macronutrient energy distributions of both menu types were within recommended ranges, plant-based menus tended to have higher carbohydrate ratios and lower protein and fat ratios. Furthermore, schools were more likely to serve plant-based menus that fell short of the nutritional standards for several nutrients. Some plant-based menus were identified as nutritionally unbalanced, revealing fundamental shortcomings in menu design-particularly an overreliance on carbohydrate- and fat-rich foods as staples, side dishes, and desserts, as well as frequent use of oil-based cooking methods.

Conclusion: Overall, these findings suggest a need for review and re-examination of the nutritional aspects of plant-based menus currently served in Seoul's elementary school meals.