Dietary Isoflavone Intake and Breast Cancer Prognosis: A Prospective Analysis and Meta-Analysis.

We aimed to examine the association between dietary isoflavone intake and the risk of breast cancer recurrence and summarize evidence on the role of dietary isoflavone intake in breast cancer prognosis. This prospective study included 592 breast cancer survivors who completed a dietary assessment. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. Of the studies published until May 31, 2023, that were searched in PUBMED and EMBASE databases, 14 studies were selected. Adjusted HRs were combined using fixed- or random-effects models. During the median follow-up of 4.3 years, 47 recurrences were identified. The HR (95% CI) for recurrence comparing the highest versus the lowest tertile of isoflavones intake was 1.29 (0.60-2.78). In a meta-analysis of previously published data and ours, dietary isoflavone intake was associated with a better breast cancer prognosis. The combined HRs (95% CIs) comparing the extreme categories were 0.81 (0.67-0.98) for recurrence and 0.85 (0.76-0.96) for all-cause mortality. A nonlinear inverse association was observed between isoflavone intake and the risk of recurrence and all-cause mortality. Our study suggests that dietary isoflavone intake is associated with a favorable prognosis in breast cancer survivors and warrants further investigation.

Effect of COVID-19 response work experience on turnover intention among employees of dedicated COVID-19 hospitals in Seoul.

BACKGROUND: According to previous studies, stress and job burnout among medical personnel increased during the COVID-19 pandemic. This study analyzed the effect of the experience of COVID-19 response work on the intention of municipal hospital staffs to leave their workplaces during the pandemic. METHODS: The 3556 employees who had worked for more than 1 year at one of the eight Seoul Municipal Hospitals that either provided inpatient treatment for quarantined COVID-19 patients or operated as screening clinics were taken as the study population. In total, 1227 employees completed a web or mobile survey between October 21 and November 18, 2020. A chi-squared test was performed to confirm the difference in the distribution of turnover intention depending on whether the employees performed COVID-19 response tasks. Multiple logistic regression analyses were performed to determine the factors that affected the intention to leave. RESULTS: Of the 1227 respondents, 761 (62.0%) were frontline workers who were the first line of response to COVID-19. Experience with COVID-19 response tasks (OR = 1.59, p = 0.003) was significantly associated with the intention to leave. Additionally, the probability of turnover intention was significantly higher among workers aged 20-29 years (OR = 2.11, p = 0.038) and 40-49 years (OR = 1.57, p = 0.048), unmarried individuals (OR = 1.66, p = 0.005), doctors (OR = 2.41, p = 0.010), nurses (OR = 1.59, p = 0.036), and technical staff members (OR = 2.22, p = 0.009). High turnover intention was found among those who experienced high levels of burnout (OR = 2.03, p < 0.001) and those working in non-directly managed municipal hospitals (OR = 1.87, p = 0.018). CONCLUSION: Employees directly involved in COVID-19 response work displayed higher turnover intention. Various personal, job, and organizational factors significantly influenced employees' intentions to leave their positions in dedicated COVID-19 hospitals. These findings suggest the necessity of introducing management programs to aid workers who have experienced sudden changes in their duties and loss of autonomy while performing COVID-19 response tasks.

Validation of resonance Raman spectroscopy-measured skin carotenoid status as a biomarker for fruit and vegetable intake in Korean adults.

Blood carotenoid concentration measurement is considered the gold standard for fruit and vegetable (F&V) intake estimation; however, this method is invasive and expensive. Recently, skin carotenoid status (SCS) measured by optical sensors has been evaluated as a promising parameter for F&V intake estimation. In this cross-sectional study, we aimed to validate the utility of resonance Raman spectroscopy (RRS)-assessed SCS as a biomarker of F&V intake in Korean adults. We used data from 108 participants aged 20-69 years who completed SCS measurements, blood collection and 3-d dietary recordings. Serum carotenoid concentrations were quantified using HPLC, and dietary carotenoid and F&V intakes were estimated via 3-d dietary records using a carotenoid database for common Korean foods. The correlations of the SCS with serum carotenoid concentrations, dietary carotenoid intake and F&V intake were examined to assess SCS validity. SCS was positively correlated with total serum carotenoid concentration (r = 0·52, 95 % CI = 0·36, 0·64, P < 0·001), serum ß-carotene concentration (r = 0·60, 95 % CI = 0·47, 0·71, P < 0·001), total carotenoid intake (r = 0·20, 95 % CI = 0·01, 0·37, P = 0·04), ß-carotene intake (r = 0·30, 95 % CI = 0·11, 0·46, P = 0·002) and F&V intake (r = 0·40, 95 % CI = 0·23, 0·55, P < 0·001). These results suggest that SCS can be a valid biomarker of F&V intake in Korean adults.

Evaluation of a Commercial Device Based on Reflection Spectroscopy as an Alternative to Resonance Raman Spectroscopy in Measuring Skin Carotenoid Levels: Randomized Controlled Trial.

Resonance Raman spectroscopy (RRS) has been used as a reference method for measuring skin carotenoid levels (SCL), which indicate vegetable and fruit intake. However, RRS is not an easy-to-use method in SCL measurement due to its complicated implementation. In this study, a commercial spectrophotometer based on reflection spectroscopy (RS), which is relatively simple and inexpensive, was evaluated to confirm usability compared with RRS in measuring SCL. To investigate the agreement between RS and RRS, eighty participants were randomly assigned to a high-carotenoid diet group (21 mg/day of total carotenoids) or a control-carotenoid diet group (14 mg/day of total carotenoids) during a 6-week whole-diet intervention period and a 4-week tracking period. Strong correlations between the RS and RRS methods were observed at baseline (r = 0.944) and the entire period (r = 0.930). The rate of SCL increase was similar during the diet intervention; however, the initiation of the SCL decrease in RS was slower than in RRS during the tracking period. To confirm the agreement of RS and RRS from various perspectives, new visualization tools and indices were additionally applied and confirmed the similar response patterns of the two methods. The results indicate that the proposed RS method could be an alternative to RRS in SCL measurements.

Simple Sugar and Sugar-Sweetened Beverage Intake During Adolescence and Risk of Colorectal Cancer Precursors.

BACKGROUND & AIMS: Recent increasing trends in early-onset colorectal cancer (CRC) strongly supports that early-life diet is involved in CRC development. However, data are lacking on the relationship with high sugar intake during early life. METHODS: We prospectively investigated the association of adolescent simple sugar (fructose, glucose, added sugar, total sugar) and sugar-sweetened beverage (SSB) intake with CRC precursor risk in 33,106 participants of the Nurses' Health Study II who provided adolescent dietary information in 1998 and subsequently underwent lower gastrointestinal endoscopy between 1999 and 2015. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression for clustered data. RESULTS: During follow-up, 2909 conventional adenomas (758 high-risk) and 2355 serrated lesions were identified (mean age at diagnoses, 52.2 ± 4.3 years). High sugar and SSB intake during adolescence was positively associated with risk of adenoma, but not serrated lesions. Per each increment of 5% of calories from total fructose intake, multivariable ORs were 1.17 (95% CI, 1.05-1.31) for total and 1.30 (95% CI, 1.06-1.60) for high-risk adenoma. By subsite, ORs were 1.12 (95% CI, 0.96-1.30) for proximal, 1.24 (95% CI, 1.05-1.47) for distal, and 1.43 (95% CI, 1.10-1.86) for rectal adenoma. Per 1 serving/day increment in SSB intake, ORs were 1.11 (95% CI, 1.02-1.20) for total and 1.30 (95% CI, 1.08-1.55) for rectal adenoma. Contrary to adolescent intake, sugar and SSB intake during adulthood was not associated with adenoma risk. CONCLUSIONS: High intake of simple sugars and SSBs during adolescence was associated with increased risk of conventional adenoma, especially rectal adenoma.

Smoking and alcohol consumption influence the risk of cardiovascular diseases in Korean adults with elevated blood pressure.

BACKGROUND AND AIMS: Cardiovascular disease (CVD) and hypertension are the main causes of global death. We aimed to investigate the independent and combined effects of smoking and alcohol consumption on CVD risk among Koreans with elevated blood pressure (BP). METHODS AND RESULTS: Adults aged 20-65 years with elevated BP and without pre-existing CVDs were selected from the National Health Insurance Service-National Sample Cohort version 2.0. We followed up 59,391 men and 35,253 women between 2009 and 2015. The association of CVD incidence with smoking pack-years and alcohol consumption was investigated using the multivariate Cox proportional hazard model. Among women, smokers (10.1-20.0 pack-years) and alcohol drinkers (≥30.0 g/day) had higher CVD risks (hazard ratio [HR] = 1.15, 95% confidence intervals [CI] 1.06-1.25, HR = 1.06, 95% CI 1.00-1.12, respectively) compared to each referent group. However, men who smoked exhibited an increased CVD risk only with pack-years >20.0 (HR = 1.09, 1.03-1.14 and HR = 1.18, 1.11-1.26 for smokers with 20.1-30.0 and ≥ 30.1 pack-years, respectively) compared to nonsmokers. In the combined groups of those smoking and consuming alcohol, only nonsmoking men consuming alcohol 1.0-29.9 g/day had a lower CVD risk than did nonsmoking, nondrinking men (HR = 0.90, 0.83-0.97). Women smoking 1.0-10.0 pack-years and consuming alcohol ≥30.0 g/day had a higher CVD risk (HR = 1.25, 1.11-1.41) than nonsmoking and nondrinking women. CONCLUSION: Smoking and alcohol consumption, independently and jointly, were associated with CVD risk in men and women. Women had a greater CVD risk than did men among Korean adults with elevated BP.

Effect of a balanced Korean diet on metabolic risk factors among overweight/obese Korean adults: a randomized controlled trial.

PURPOSE: This study was to see the effects of a balanced Korean diet (BKD) on metabolic risk factors in overweight or obese Korean adults, comparing with those of a typical American diet (TAD) and a diet recommended by the 2010 Dietary Guidelines for Americans (2010DGA). METHODS: The study was designed as a randomized crossover controlled trial, in which 61 overweight or obese volunteers were divided into six groups and each consumed the BKD, 2010DGA, and TAD in a random order for 4 weeks separated by 2-week washout intervals. Anthropometric indices, blood pressure, blood lipid content, fasting blood glucose, and blood insulin level were measured at the beginning and end of each diet period. RESULTS: A total of 54 participants completed the trial. The BKD caused more significant reductions of body mass index (BMI) (p < 0.001), body fat percent (p < 0.001), blood total cholesterol (p < 0.001), and low-density lipoprotein (LDL) cholesterol (p = 0.007) compared with the 2010DGA or TAD (all p values for differences between diets < 0.05). All three diets significantly lowered blood triglyceride levels (p < 0.05). The BKD decreased high-density lipoprotein (HDL) cholesterol (p = 0.001) and increased fasting blood glucose (p = 0.018), whereas TAD and 2010DGA increased HDL cholesterol and did not affect blood glucose levels. Furthermore, the BKD significantly decreased the proportion of individuals with elevated total cholesterol (p < 0.001) and LDL cholesterol (p < 0.01), whereas the 2010DGA significantly reduced the number of obese individuals (p < 0.05), and the TAD decreased the number of participants with elevated triglyceride levels (p < 0.05), but increased that of those with elevated LDL cholesterol (p < 0.05). CONCLUSIONS: The Korean diet based on dietary guidelines improved metabolic risk factors such as BMI, body fat percent, and blood lipid profiles in overweight or obese Korean adults. These results provide evidence to recommend the Korean diet for preventing various metabolic diseases. CLINICAL TRIAL REGISTRATION: The trial was registered at the Clinical Research Information Service (CRIS) in Korea, the primary registry of the World Health Organization (WHO) international clinical trial registry platform, under number KCT0002437.

Impact of dietary protein intake and obesity on lean mass in middle-aged individuals after a 12-year follow-up: the Korean Genome and Epidemiology Study (KoGES).

The present study investigated the association between protein intake and lean mass according to obesity status over a 12-year period. Data on 4412 participants aged 40-69 years were obtained from the Korean Genome and Epidemiology Study. The usual dietary protein intake of these participants was assessed at baseline using a semi-quantitative FFQ. Body composition was measured using bioelectrical impedance analysis at baseline and after a 12-year follow-up. Linear mixed-effects models were used to examine the associations between lean mass after a 12-year follow-up and protein intake at baseline. After adjusting for covariates and lean mass at baseline, comparisons between the highest and lowest tertiles revealed that dietary protein intake was positively associated with lean mass in both men (ß = 0·79, P = 0·001) and women (ß = 0·28, P = 0·082) after the 12-year period; however, those differences were attenuated after additional adjustment for fat mass at baseline and were stronger in the normal-weight group (men, ß = 0·85, P = 0·002; women, ß = 0·97, P < 0·001) but were not detected in the obese group. In the obese group, age (men, ß = 4·08, P < 0·001; women, ß = 2·61, P < 0·001) and regular physical activity (men, ß = 0·88, P = 0·054; women, ß = 0·76, P < 0·001) were significantly associated with lean mass after 12 years of follow-up. The results of the present study showed that protein intake may contribute to the prevention of ageing-related lean mass loss; however, the impact of this intake may vary depending on obesity status. Therefore, the maintenance of a healthy body weight during ageing through enhanced protein intake is likely to confer health benefits.

Dietary pattern, dietary total antioxidant capacity, and dyslipidemia in Korean adults.

BACKGROUND: Abnormal diet is considered to be an important risk factor for dyslipidemia. However, so far, most studies have focused on the association between single factors only, such as specific nutrients, foods, or dietary patterns, and dyslipidemia risk. This study aimed to examine the association of the joint interaction between dietary pattern and dietary total antioxidant capacity (TAC) with dyslipidemia. METHODS: We performed a dietary pattern analysis and calculated the dietary TAC based on 24-h dietary recall (DR) data from Korea National Health and Nutrition Examination Survey (KNHANES) 2007-2012, which is representative population-based cross-sectional survey in Korea. A total of 29,624 participants aged over 19 years were included for the analysis. The number of people with hypercholesterolemia, hypertriglyceridemia, and hypoHDL-cholesterolemia was 3703, 3513, and 9802, respectively. We examined the association between the joint classifications of dietary pattern score tertiles and dietary TAC level tertiles and dyslipidemia. RESULTS: Our results demonstrated that the "Rice & Kimchi" pattern was associated with low prevalence of hypercholesterolemia, and high prevalence of hypertriglyceridemia and hypoHDL-cholesterolemia; whereas the pattern of both "Oil, sweets, fish & other vegetables" and "Grain, bean, nuts, vegetables & fruits" were associated with low prevalence of hypertriglyceridemia. Also we demonstrated that for all dietary patterns except for the "Grain, bean, nuts, vegetables & fruits", dietary TAC was inversely associated with hypertriglyceridemia. CONCLUSION: This study provides basic data for the lipid-lowering effect of dietary TAC and its interaction with dietary patterns. Further study will be needed to investigate the association between dietary TAC and dietary patterns with other diseases like metabolic syndrome, cardiovascular disease, or cancer.

Estimation of dietary total antioxidant capacity of Korean adults.

PURPOSE: Dietary total antioxidant capacity (TAC) has been reported to be inversely associated with the risk of chronic diseases. However, little is known about dietary TAC among the Korean population. Therefore, we aimed to estimate the dietary TAC of Korean adults and to document the major food sources. METHODS: We studied 33,581 Korean adults aged ≥19 years who participated in the Korea National Health and Nutrition Examination Survey 2007-2012. Dietary TAC was estimated from 1-day 24-h dietary recall data using a TAC database comprising antioxidant capacities of 42 dietary antioxidants, developed for common Korean foods. RESULTS: The average dietary TAC of Korean adults was 384.7 mg VCE/d, and the major contributors were flavonoids, followed by vitamin C and E. The energy-adjusted daily TAC level was higher in women, middle-aged adults, non-regular alcohol consumers, current non-smokers, supplement users, and in those with a higher income and education level than in their counterparts (P < 0.001). Fruits (47.3%), vegetables (28.4%), beverages and alcohols (11.2%), and legumes and legume products (5.5%), in particular, grapes, persimmons, mandarins, apples, and green tea, were major food sources of dietary TAC. In addition, the consumption of nutrient-dense foods, such as fruits and vegetables, increased, whereas the intake of energy and fat decreased across quartiles of energy-adjusted dietary TAC. CONCLUSIONS: The present study documented the baseline dietary TAC of Korean adults and the major food sources thereof using nationally representative data. Further research on the health effects of dietary TAC among Korean adults is warranted.

Associations of Dietary Antioxidants and Risk of Type 2 Diabetes: Data from the 2007-2012 Korea National Health and Nutrition Examination Survey.

Antioxidants are suggested to decrease risk of type 2 diabetes (T2D) by preventing progressive impairment of pancreatic ß-cell and endothelial function. This study was aimed to investigate the association between dietary antioxidants and risk of T2D in Korean adults based on a national representative data. A total of 24,377 adults (19-74 years) who completed one-day 24 h dietary recall and health examination were included. Dietary antioxidant intakes including α-carotene (p < 0.0001), lycopene (p = 0.0107), flavan-3-ols (p < 0.0001), and proanthocyanidins (p = 0.0075) were significantly higher in non-diabetic subjects than in diabetic subjects. After adjusting for confounding variables, the highest quartile group of α-carotene intake was associated with a 48% reduced risk of T2D in men (OR: 0.52, 95% CI: 0.34-0.80, p for trend = 0.0037) and a 39% reduced risk in women (OR: 0.61, 95% CI: 0.38-0.996, p for trend = 0.0377) compared to the lowest quartile group. Men in the highest quartile of ß-carotene intake showed lower risk of T2D (OR: 0.64, 95% CI: 0.42-0.97), but no significant decreasing trend. However, the intakes of total carotenoids and other antioxidants showed no significant association with the risk of T2D. These findings suggest that a further comprehensive approach which considers overall dietary pattern is required.

Estimation of dietary flavonoid intake and major food sources of Korean adults.

Epidemiological studies have suggested that flavonoids exhibit preventive effects on degenerative diseases. However, lack of sufficient data on flavonoid intake has limited evaluating the proposed effects in populations. Therefore, we aimed to estimate the total and individual flavonoid intakes among Korean adults and determine the major dietary sources of these flavonoids. We constructed a flavonoid database of common Korean foods, based on the food list reported in the 24-h recall of the Korea National Health and Nutrition Examination Survey (KNHANES) 2007-2012, using data from the Korea Functional Food Composition Table, US Department of Agriculture flavonoid database, Phenol-Explorer database and other analytical studies. This database, which covers 49 % of food items and 76 % of food intake, was linked with the 24-h recall data of 33 581 subjects aged ≥19 years in the KNHANES 2007-2012. The mean daily intake of total flavonoids in Korean adults was 318·0 mg/d, from proanthocyanidins (22·3%), flavonols (20·3%), isoflavones (18·1%), flavan-3-ols (16·2%), anthocyanidins (11·6%), flavanones (11·3%) and flavones (0·3%). The major contributing food groups to the flavonoid intake were fruits (54·4%), vegetables (20·5%), legumes and legume products (16·2%) and beverages and alcohols (3·1%), and the major contributing food items were apples (21·9%), mandarins (12·5%), tofu (11·5%), onions (9·6%) and grapes (9·0%). In the regression analysis, the consumption of legumes and legume products, vegetables and fruits predicted total flavonoid intake the most. The findings of this study could facilitate further investigation on the health benefits of flavonoids and provide the basic information for establishing recommended flavonoid intakes for Koreans.

Reproducibility and validity of an FFQ developed for the Korea National Health and Nutrition Examination Survey (KNHANES).

OBJECTIVE: We aimed to evaluate the reproducibility and validity of the newly developed FFQ for the Korean National Health and Nutrition Examination Survey (KNHANES) and to estimate the measure's calibration factors. DESIGN: The 109-item FFQ was administered twice, approximately 9 months apart. We also collected four seasonal 3 d dietary records (DR) as a reference method. Correlation coefficients and joint classification were computed to compare intakes of energy, thirteen nutrients and eleven food groups between the two FFQ to evaluate reproducibility. For validity, de-attenuated and energy-adjusted correlation, joint classification and Bland-Altman statistics were calculated for energy and nutrients between the first FFQ and the DR. To calibrate the FFQ, we performed a linear regression analysis in which the DR were the dependent variables and FFQ, age and sex were the independent variables. SETTING: Seoul metropolitan area, Republic of Korea. SUBJECTS: A total of 126 adults aged 20-65 years. RESULTS: The average correlation coefficients measuring reproducibility were 0·54 for nutrients and 0·57 for food groups. The mean correlation coefficient measuring validity was 0·40 for all nutrients between the first FFQ and the DR. On average, 75 % of the participants were classified into the same or adjacent quartiles, while 5 % of the participants were grossly misclassified. The mean energy and nutrient intakes estimated by the calibrated FFQ were similar to the means estimated by the DR. CONCLUSIONS: The newly developed FFQ for assessing dietary intake in the KNHANES has acceptable reproducibility and modest validity compared with a 12 d DR collected over a 9-month period.

Red meat consumption is associated with an increased overall cancer risk: a prospective cohort study in Korea.

Cancer is a leading cause of death, and the dietary pattern in Korea is changing rapidly from a traditional Korean diet to a Westernised diet. In the present study, we investigated the effects of dietary factors on cancer risk with a prospective cohort study. Among 26,815 individuals who participated in cancer screening examinations from September 2004 to December 2008, 8024 subjects who completed a self-administered questionnaire concerning demographic and lifestyle factors, and a 3 d food record were selected. As of September 2013, 387 cancer cases were identified from the National Cancer Registry System, and the remaining individuals were included in the control group. The hazard ratio (HR) of cancer for the subjects older than or equal to 50 years of age was higher (HR 1.80, 95% CI 1.41, 2.31; P< 0.0001) than that for the other subjects. Red meat consumption, Na intake and obesity (BMI ≥ 25 kg/m²) were positively associated with overall cancer incidence in men (HR 1.41, 95% CI 1.02, 1.94; P= 0.0382), gastric cancer (HR 2.34, 95% CI 1.06, 5.19; P= 0.0365) and thyroid cancer (HR 1.56, 95% CI 1.05, 2.31; P= 0.0270), respectively. Participants who had at least three dietary risk factors among the high intakes of red meat and Na, low intakes of vegetables and fruits, and obesity suggested by the World Cancer Research Fund/American Institute for Cancer Research at baseline tended to have a higher risk of cancer than the others (HR 1.26, 95% CI 0.99, 1.60; P= 0.0653). In summary, high intakes of red meat and Na were significant risk factors of cancer among Koreans.

Inadequate calcium intake is highly prevalent in Korean children and adolescents: the Korea National Health and Nutrition Examination Survey (KNHANES) 2007-2010.

OBJECTIVE: The present study aimed to assess the adequacy of Ca intake and major food sources of Ca in Korean children and adolescents. DESIGN: A cross-sectional study. SETTING: Data from the Korean National Health and Nutrition Examination Survey (KNHANES) 2007-2010. We analysed the daily Ca intake, major food sources of Ca and the prevalence of inadequate Ca intake in the study population. Ca intake was categorized as inadequate when the participant's daily Ca intake was less than the Estimated Average Requirement. Subject The study population consisted of 7233 children and adolescents (3973 boys, 3260 girls; aged 1-18 years). RESULTS: Mean Ca intake was 510·2 mg/d in boys and 431·7 mg/d in girls. Overall, 75·0 % of adolescents (boys 71·6 %, girls 79·1 %) had inadequate Ca intake. The prevalence of inadequate Ca intake increased significantly from toddlers (45-55 %) to adolescents (78-86 %) in both genders. The highest ranked food sources for Ca were dairy products (35·0 %), followed by vegetables (17·3 %), grains (11·3 %) and seafood (9·9 %). Ca intake from dairy products decreased significantly from 57 % in toddlers to 30 % in adolescents, while Ca intakes from other foods increased with age. CONCLUSIONS: Inadequate Ca intake is highly prevalent and increased with age in Korean children and adolescents. It should be emphasized to encourage children and adolescents to eat more Ca-rich products to meet their Ca needs.

Urine metabolomics unravel the effects of short-term dietary interventions on oxidative stress and inflammation: a randomized controlled crossover trial.

Dietary biomarkers in urine remain elusive when evaluating diet-induced oxidative stress and inflammation. In our previous study, we conducted a randomized controlled crossover trial to compare the short-term (4-weeks) effects of the balanced Korean diet (BKD) with Western diets, including the 2010 dietary guidelines for Americans (2010 DGA) and typical American diet (TAD), on various metabolic indices in obese Korean adults. Building on this work, the current research focuses on the impact of these dietary interventions on oxidative stress (d-ROMs and BAP) and inflammation (CRP, TNF-α, IL-6, IL-1ß, MCP-1) biomarkers in serum, and the concurrent urine metabolomes. Each dietary regimen was in silico and experimentally examined for their antioxidant levels using ABTS, DPPH, and FRAP assays, as well as total flavonoid (TFC) and total phenolic (TPC) contents. We assessed post-intervention variations in oxidative stress and inflammation biomarkers in serum, as well as the urine metabolite profiles for the participants (n = 48, average age: 41 years). Antioxidant contents and associated total antioxidant capacity (TAC) were significantly higher for the recommended diets (BKD and 2010 DGA) compared to TAD (p < 0.05). Butanol extracts from recommended diets (BKD and 2010 DGA) showed significantly higher antioxidant activity compared to TAD in ABTS (p < 0.01), DPPH, and FRAP (p < 0.05) assays. Consistent results were observed in total phenolic and flavonoid contents, mirroring their respective antioxidant activities. Following the intervention period, oxidative stress & inflammation markers in serum varied marginally, however, the urine metabolite profiles were clearly demarcated for the BKD and Western dietary groups (PC1 = 5.41%). For BKD group, the pre- and post-intervention urine metabolite profiles were clearly segregated (PLS2 = 2.93%). Compared to TAD, urine extracts from the recommended dietary group showed higher abundance of benzoic acid & phenolic derivatives (VIP > 0.7, p < 0.05). Metabolites associated with oxidative stress were observed higher in the urine samples from Western dietary groups compared to BKD. Urine metabolomics data delineated the post-intervention effects of three dietary interventions which corroborates the respective findings for their effects on metabolic indices.

Examination of the utility of skin carotenoid status in estimating dietary intakes of carotenoids and fruits and vegetables: A randomized, parallel-group, controlled feeding trial.

OBJECTIVE: Optical spectroscopy-measured skin carotenoid status (SCS) has been validated for estimating fruit and vegetable (F&V) intake; however, there is limited research addressing SCS kinetics in whole-diet interventions. The aim of this controlled feeding trial was to explore SCS's response to carotenoid intake changes via whole-diet intervention, evaluating its biomarker potential. METHODS: Eighty participants ages 20 to 49 y, without underlying diseases, were randomly allocated to the high-carotenoid group (HG; n = 40) or control group (CG; n = 40). The HG consumed a high-carotenoid diet (21 mg total carotenoids/2000 kcal), whereas the CG consumed a control diet (13.6 mg total carotenoids/2000 kcal) for 6 wk. Subsequently, skin and blood carotenoid concentrations were tracked without intervention for 4 wk. SCS was measured weekly via resonance Raman spectroscopy, and serum carotenoid concentrations were analyzed biweekly using high-performance liquid chromatography. Baseline carotenoid and F&V intakes were assessed via a 3-d diet record. The kinetics of SCS and serum carotenoid concentrations were analyzed using a weighted generalized estimating equation. Pearson's correlation analyses were used to examine baseline correlations between SCS and dietary carotenoid and F&V intakes, as well as serum carotenoid concentrations. RESULTS: During the intervention, the HG showed a faster and greater SCS increase than the CG (difference in slope per week = 8.87 AU, Pinteraction <0.001). Baseline SCS had positive correlations with total carotenoid intake (r = 0.45), total F&V intake (r = 0.49), and total serum carotenoid concentration (r = 0.79; P < 0.001 for all). CONCLUSION: These results suggest that SCS is a valid biomarker for monitoring changes in carotenoid intake through whole diet, which supports using SCS for assessing carotenoid-rich F&V intake.

A dairy and fruit dietary pattern is associated with a reduced likelihood of osteoporosis in Korean postmenopausal women.

The aim of the present study was to identify the association of dietary patterns with osteoporosis in Korean postmenopausal women from the Korean Health and Nutrition Examination Survey 2008­10. The present cross-sectional analysis included 3735 postmenopausal women who completed a health interview, nutrition survey and a health examination including bone mineral density (BMD) measurements. The general characteristics and dietary intakes of the participants were obtained using a standardised questionnaire and a 24 h recall method, respectively. The BMD of the femoral neck and lumbar spine was measured using dual-energy X-ray absorptiometry; osteoporosis was defined based on the WHO T-score criteria. Overall, we identified four dietary patterns using factor analysis as follows: 'meat, alcohol and sugar', 'vegetables and soya sauce', 'white rice, kimchi and seaweed' and 'dairy and fruit', which accounted for 30·9% of the total variance in food intake (11·3, 7·7, 6·0 and 5·9%, respectively). The subjects in the highest quintile of the 'dairy and fruit' pattern showed a decreased risk of osteoporosis of the lumbar spine (53 %) compared with those in the lowest quintile, after adjusting for covariates (OR 0·47, 95% CI 0·35, 0·65, P for trend<0·0001). In contrast, the 'white rice, kimchi and seaweed' dietary pattern was negatively associated with bone health (OR 1·40, 95% CI 1·03, 1·90, P for trend=0·0479). The present results suggest that an increased intake of dairy foods and fruits in the traditional Korean diet, based on white rice and vegetables, may decrease the risk of osteoporosis in Korean postmenopausal women.

Sources of variation in nutrient intake and the number of days to assess usual intake among men and women in the Seoul metropolitan area, Korea.

Sources of variation in nutrient intake have been examined for Western diets, but little is known about the sources of variation and their differences by age and sex among Koreans. We examined sources of variation in nutrient intake and calculated the number of days needed to estimate usual intake using 12 d of dietary records (DR). To this end, four 3 d DR including two weekdays and one weekend day were collected throughout four seasons of 1 year from 178 male and 236 female adults aged 20-65 years residing in Seoul, Korea. The sources of variation were estimated using the random-effects model, and the variation ratio (within-individual:between-individual) was calculated to determine a desirable number of days. Variations attributable to the day of the week, recording sequence and seasonality were generally small, although the degree of variation differed by sex and age (20-45 years and 46-65 years). The correlation coefficient between the true intake and the observed intake (r) increased with additional DR days, reaching 0·7 at 3-4 d and 0·8 at 6-7 d. However, the degree of increase became attenuated with additional days: r increased by 13·0-26·9 % from 2 to 4 d, by 6·5-16·4 % from 4 to 7 d and by 4·0-11·6 % from 7 to 12 d for energy and fifteen nutrients. In conclusion, the present study suggests that the day of the week, recording sequence and seasonality minimally contribute to the variation in nutrient intake. To measure Korean usual dietary intake using open-ended dietary instruments, 3-4 d may be needed to achieve modest precision (r>0·7) and 6-7 d for high precision (r>0·8).

Development of a Semi-Quantitative Food-Frequency Questionnaire for Korean Adults with Obesity.

The increasing prevalence of obesity is a serious concern in Korea. However, there is currently no available food-frequency questionnaire (FFQ) for examining the dietary patterns of adults with obesity. This study aimed to develop a semi-quantitative FFQ tailored to Korean adults with obesity. The dish/food items for the FFQ were extracted from the 24 h recall data of 8450 Korean adults (aged 19-64 years) with obesity who participated in the 2013-2019 Korea National Health and Nutrition Examination Survey. Among the 1709 dishes consumed, 475 were selected based on their high contribution to the intake or substantial between-individual variation in 11 nutrients: energy, carbohydrates, dietary fiber, sugar, fat, saturated fat, protein, sodium, vitamin A, vitamin E, and flavonoids. These dishes were subsequently categorized into 129 items based on their recipes and primary ingredients. The final 129 items included rice; noodles and dumplings; breads, rice cakes, and cereals; soups and stews; eggs, pulses, meat, and fish; vegetables and kimchi; fruit; snacks; beverages; milk/dairy products; alcohol; and water. The response options for intake frequency comprised nine options, and the intake amount response included three options (50%, 100%, and 150-200% of the standard intake). After validation, this FFQ is expected to be used in epidemiological studies to investigate the dietary patterns of Korean adults with obesity.