This review summarizes the establishment of the 2025 Dietary Reference Intakes for Koreans (KDRIs), the third national standard for nutrient reference values in Korea. The 2025KDRIs build on lessons from revisions in 2010, 2015, and 2020, and chart a path forward by addressing 4 priorities: upgrading the scientific evidence base through systematic evaluation, strengthening intake monitoring using national survey data, advancing international harmonization, and responding to changes in the nutrition and health environment, including those associated with the coronavirus disease 2019 (COVID-19) pandemic. The scientific basis of the KDRIs was advanced by systematically evaluating the findings across exposure indicators, health assessment indicators, and the health outcomes, and reorganizing the indicators to estimate the nutrient requirements. Adequate Intake was set using explicit criteria when an Estimated Average Requirement could not be derived, data gaps, uncertain outcomes, and limited representativeness were documented. Key inputs, including coefficients of variation and uncertainty factors, as well as life stage estimation procedures, were re-evaluated in alignment with current evidence and international standards. The 2025 KDRIs incorporate intake evidence from the Korea National Health and Nutrition Examination Survey to inform policy and practice and support intake monitoring. For international harmonization, the NUQUEST-based literature framework was updated, and recent DRIs from other countries were compared. The shifts in anthropometric characteristics and dietary intake patterns observed during the COVID-19 pandemic were considered to reflect a changing context. The review identified remaining challenges for future revisions, including validating Koreanspecific indicators, developing evidence for infants and older adults, stronger translation of reference values into policy and practice, prioritizing of nutrients for future review within the 5-year revision cycle. Together, these advances will position the 2025 KDRIs as a science-based national reference integrating policy, practice, and evidence to support implementation aimed at improving nutritional status and healthy life expectancy in Korea.

BACKGROUND/OBJECTIVES: Particulate matter 2.5 (PM2.5) exposure can promote epithelialmesenchymal transition (EMT) in human retinal pigment epithelial (RPE) cells. The flowers of Tagetes erecta Linn, commonly known as marigold, are rich in diverse flavonoids and carotenoids and play a significant role in preventing cellular damage induced by oxidative stress, but the role of their extracts in RPE cells has not been reported. This study aimed to evaluate the influence of an ethanol extract of T. erecta Linn flower (TE) on PM2.5-induced EMT processes in RPE ARPE-19 cells.MATERIALS/METHODS: To investigate the protective effect of TE against ARPE-19 cell damage following PM2.5 treatment, cells were exposed to TE for 1 h before exposure to PM2.5 for 24 h. We investigated whether the efficacy of TE on suppressing PM2.5-induced EMT was related to antioxidant activity and the effect on the expression changes of factors involved in EMT regulation. Additionally, we further explored the role of intracellular signaling pathways associated with EMT inhibition. RESULTS: TE significantly blocked PM2.5-induced cytotoxicity while effectively preventing mitochondrial dysfunction, increased reactive oxygen species (ROS) generation, and mitochondrial membrane potential disruption. TE inhibited PM2.5-induced EMT and inflammatory response by suppressing the ROS-mediated transforming growth factor-β/ suppressor of mothers against decapentaplegic/mitogen-activated protein kinases signaling pathway. CONCLUSION Our results suggest that marigold extract is a highly effective in protection against PM2.5-induced eye damage.

Background: Cumulative evidence consistently shows that anthropometric and body composition measurements are strongly linked to the risk of incident diabetes, typically based on baseline measurements. This study aims to assess whether repeated measurements enhance the prediction of diabetes risk beyond baseline assessments alone. Methods: We utilized data from a 16-year population-based follow-up cohort within the Korean Genome and Epidemiology Study, comprising 6,030 individuals aged 40 to 69 years at baseline. We included eight indices: a body shape index (ABSI), body adiposity index (BAI), waist circumference (WC), body mass index (BMI), waist-to-hip ratio (WHR), weight-adjusted skeletal muscle index (SMI), percent body fat, and fat-to-muscle ratio. The effect of these measurements for incident diabetes was estimated using Harrell’s C-indexes and hazard ratios with 95% confidence intervals, employing time-dependent Cox proportional hazard models. Results: Over the 16-year follow-up, 939 new diabetes cases were identified (cumulative incidence, 15.6%). The median number of indicator measurements per participant was eight. The basic model, including 10 features (sex, age, education levels, physical activity, alcohol intake, current smoking, total energy intake, dietary diversity score, and log-transformed C-reactive protein levels, and quartiles of unweighted genetic risk score at baseline), yielded a Harrell’s C-index of 0.610. The highest C-index in repeated measurements was for WC (0.668) across the general population, weight-adjusted SMI in men, and WHR in women. However, except for ABSI and BAI, the diabetes predictive power of the other indicators was comparable. Additionally, repeated measurements of WC, BMI, and WHR in women were found to contribute to improved discrimination compared to baseline measurements, but not in men. Conclusion Utilizing repeated measurements of general and central adiposity to predict diabetes may be helpful in predicting hidden risks, especially in women.

OBJECTIVES: Low handgrip strength (HGS) in children and adolescents might be associated with the risk of metabolic syndrome (MetS) and insulin resistance. This study prospectively evaluated the association between HGS in childhood and MetS in adolescence. METHODS: Based on data from the Ewha Birth and Growth Study, this study analyzed HGS at ages 7 to 9 and metabolic indices at ages 13 to 15. In total, 219 participants were analyzed. The risk of MetS was evaluated using the continuous metabolic syndrome score (cMetS), and insulin resistance was assessed using fasting blood insulin and homeostasis model assessment of insulin resistance (HOMA-IR). Relative HGS in childhood was determined by dividing HGS by body weight and categorized as sex-specific quartiles. RESULTS: This study found an inverse association between relative HGS levels in childhood and MetS and insulin resistance in adolescence. For each 1-group increase in relative HGS quartiles, cMetS (standarard [Std] β=-0.64, p<0.01), HOMA-IR (Std β=-0.21, p<0.01), and fasting blood insulin (Std β=-0.21, p<0.01) all decreased on average. These associations remained significant even after adjusting for confounding factors. CONCLUSIONS Our study showed a prospective association between HGS in childhood and the risk of MetS and insulin resistance in adolescence. It provides significant epidemiological evidence, emphasizing the importance of efforts to increase muscle strength from a young age to mitigate the risk of MetS and insulin resistance in adolescence.

Background: Cumulative evidence consistently shows that anthropometric and body composition measurements are strongly linked to the risk of incident diabetes, typically based on baseline measurements. This study aims to assess whether repeated measurements enhance the prediction of diabetes risk beyond baseline assessments alone. Methods: We utilized data from a 16-year population-based follow-up cohort within the Korean Genome and Epidemiology Study, comprising 6,030 individuals aged 40 to 69 years at baseline. We included eight indices: a body shape index (ABSI), body adiposity index (BAI), waist circumference (WC), body mass index (BMI), waist-to-hip ratio (WHR), weight-adjusted skeletal muscle index (SMI), percent body fat, and fat-to-muscle ratio. The effect of these measurements for incident diabetes was estimated using Harrell’s C-indexes and hazard ratios with 95% confidence intervals, employing time-dependent Cox proportional hazard models. Results: Over the 16-year follow-up, 939 new diabetes cases were identified (cumulative incidence, 15.6%). The median number of indicator measurements per participant was eight. The basic model, including 10 features (sex, age, education levels, physical activity, alcohol intake, current smoking, total energy intake, dietary diversity score, and log-transformed C-reactive protein levels, and quartiles of unweighted genetic risk score at baseline), yielded a Harrell’s C-index of 0.610. The highest C-index in repeated measurements was for WC (0.668) across the general population, weight-adjusted SMI in men, and WHR in women. However, except for ABSI and BAI, the diabetes predictive power of the other indicators was comparable. Additionally, repeated measurements of WC, BMI, and WHR in women were found to contribute to improved discrimination compared to baseline measurements, but not in men. Conclusion Utilizing repeated measurements of general and central adiposity to predict diabetes may be helpful in predicting hidden risks, especially in women.

OBJECTIVES: Low handgrip strength (HGS) in children and adolescents might be associated with the risk of metabolic syndrome (MetS) and insulin resistance. This study prospectively evaluated the association between HGS in childhood and MetS in adolescence. METHODS: Based on data from the Ewha Birth and Growth Study, this study analyzed HGS at ages 7 to 9 and metabolic indices at ages 13 to 15. In total, 219 participants were analyzed. The risk of MetS was evaluated using the continuous metabolic syndrome score (cMetS), and insulin resistance was assessed using fasting blood insulin and homeostasis model assessment of insulin resistance (HOMA-IR). Relative HGS in childhood was determined by dividing HGS by body weight and categorized as sex-specific quartiles. RESULTS: This study found an inverse association between relative HGS levels in childhood and MetS and insulin resistance in adolescence. For each 1-group increase in relative HGS quartiles, cMetS (standarard [Std] β=-0.64, p<0.01), HOMA-IR (Std β=-0.21, p<0.01), and fasting blood insulin (Std β=-0.21, p<0.01) all decreased on average. These associations remained significant even after adjusting for confounding factors. CONCLUSIONS Our study showed a prospective association between HGS in childhood and the risk of MetS and insulin resistance in adolescence. It provides significant epidemiological evidence, emphasizing the importance of efforts to increase muscle strength from a young age to mitigate the risk of MetS and insulin resistance in adolescence.

BACKGROUND/OBJECTIVES: Particulate matter 2.5 (PM2.5) exposure can promote epithelialmesenchymal transition (EMT) in human retinal pigment epithelial (RPE) cells. The flowers of Tagetes erecta Linn, commonly known as marigold, are rich in diverse flavonoids and carotenoids and play a significant role in preventing cellular damage induced by oxidative stress, but the role of their extracts in RPE cells has not been reported. This study aimed to evaluate the influence of an ethanol extract of T. erecta Linn flower (TE) on PM2.5-induced EMT processes in RPE ARPE-19 cells.MATERIALS/METHODS: To investigate the protective effect of TE against ARPE-19 cell damage following PM2.5 treatment, cells were exposed to TE for 1 h before exposure to PM2.5 for 24 h. We investigated whether the efficacy of TE on suppressing PM2.5-induced EMT was related to antioxidant activity and the effect on the expression changes of factors involved in EMT regulation. Additionally, we further explored the role of intracellular signaling pathways associated with EMT inhibition. RESULTS: TE significantly blocked PM2.5-induced cytotoxicity while effectively preventing mitochondrial dysfunction, increased reactive oxygen species (ROS) generation, and mitochondrial membrane potential disruption. TE inhibited PM2.5-induced EMT and inflammatory response by suppressing the ROS-mediated transforming growth factor-β/ suppressor of mothers against decapentaplegic/mitogen-activated protein kinases signaling pathway. CONCLUSION Our results suggest that marigold extract is a highly effective in protection against PM2.5-induced eye damage.