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.
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 2008–10. 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.
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 (β = 0·79, P = 0·001) and women (β = 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, β = 0·85, P = 0·002; women, β = 0·97, P < 0·001) but were not detected in the obese group. In the obese group, age (men, β = 4·08, P < 0·001; women, β = 2·61, P < 0·001) and regular physical activity (men, β = 0·88, P = 0·054; women, β = 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.
The risk factors for metabolic syndrome may differ between Western and Asian countries due to their distinct dietary cultures. However, few studies have directly compared macronutrient intake and its ...association with the risk of metabolic syndrome in the US and Korean adults using national survey data.
Based on the data from the US and Korean versions of the 2007-2012 National Health and Nutrition Examination Survey (NHANES, KNHANES), a total of 3,324 American and 20,515 Korean adults were included. In both countries, dietary intake was measured using a 24-h dietary recall method and metabolic syndrome was defined using the National Cholesterol Education Program Adult Treatment Panel III criteria.
The percentages of energy intake from carbohydrate, protein, and fat were 50:16:33 in the US adults and 66:15:19 in the Korean adults. Regarding metabolic abnormalities, Korean adults in the highest quintile of carbohydrate intake showed an increased risk of metabolic syndrome in men and women, with abnormalities of reduced HDL cholesterol and elevated triglyceride levels. In contrast, the US men showed no significant association with metabolic syndrome and its abnormalities, while the US women showed an increased risk of reduced HDL cholesterol and elevated triglycerides.
A high carbohydrate intake is associated with metabolic abnormalities. As Korean adults consume more carbohydrate than American adults, stronger associations of dietary carbohydrate with metabolic syndrome were observed. Thus, further studies are necessary to elucidate the underlying mechanisms of different contributors to developing metabolic disease in Western and Asian populations.
This cohort study aimed to identify the associations of dairy protein intake with the risk of developing a low muscle mass during a 12-year follow-up period, using data from 4412 middle-aged Korean ...Genome and Epidemiology Study participants with a normal baseline muscle mass. Dairy protein intake at baseline was assessed using a semi-quantitative Food Frequency Questionnaire. Skeletal muscle mass index (SMI), defined as the weight-adjusted skeletal muscle mass, was measured biennially using multi-frequency bioelectrical impedance analyses. Cox proportional hazards regression analysis was used to calculate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Overall, 395 subjects developed a low SMI (%) during an average follow-up of 141 (19-152) months. The average consumption of milk and other dairy products was 73.6 and 104.1 g/day, respectively. In men, a higher dairy protein intake was associated with a decreased risk of developing a low SMI (tertile 3 T3 vs. T1, HR: 0.63; 95% CI: 0.42, 0.94;
for trend = 0.029). In a stratified analysis according to a total protein intake, this association was stronger in the lower-protein intake group (HR: 0.59; 95% CI: 0.35, 0.99;
for trend = 0.036) but not detected in the higher-protein intake group. Men who consumed milk ≥1 time/day had a significantly lower risk of developing a low SMI (HR: 0.62; 95% CI: 0.39, 0.98;
for trend = 0.023). No significant associations were observed in women. In summary, dairy consumption appears to be beneficial for decreasing the risk of developing a low muscle mass in middle-aged Korean men.
Scope
Animal protein intake among Koreans has recently increased. However, there is limited evidence on the association of meat and fish/seafood intake and mortality.
Methods and results
This study ...uses three representative prospective cohorts in Korea and 134,586 eligible participants are selected. Food intake is assessed using a food frequency questionnaire. Outcomes are classified as death from cardiovascular disease (CVD), cancer, and all‐causes. Red meat intake shows a marginally negative association with all‐cause mortality in the median intake group and a positive association in the highest intake group. Processed meat intake in the highest quintile group is positively associated with all‐cause mortality compared to that of the lowest quintile group. Fish intake in the highest quintile group is negatively associated with CVD mortality in men, and all‐cause mortality in women, compared to those in the lowest quintile group, while processed fish intake has unfavorable effects on mortality. In addition, substitution of one serving per week of red and processed meat, and processed fish with fish is negatively associated with all‐cause and CVD mortality.
Conclusion
Reduction of red and processed meat, and processed fish consumption or replacement of these foods with fish may be beneficial for longevity in Korean adults.
The effect of meat and fish/seafood intake on mortality is investigated in the Korean population. Consumption of fish is inversely associated with cardiovascular disease (CVD) and all‐cause mortality while consumption of red and processed meat, and processed fish is positively associated with all‐cause mortality. Replacement of these foods for fish results in a reduced risk of all‐cause and CVD mortality.
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.
This study aimed to determine the association between consumption of ultra-processed foods and obesity among Korean adults. We used the data of 7364 participants (men 3219, women 4145) aged 19-64 ...years from the Korea National Health and Nutrition Examination Survey (KNHANES), 2016-2018. Food items were classified using the NOVA food classification system, depending on the extent and purpose of food processing: (1) unprocessed or minimally processed foods, (2) processed culinary ingredients, (3) processed foods, and (4) ultra-processed foods. Consumption of ultra-processed foods accounted for 26.8% of the total energy intake. After adjusting for potential confounders including sociodemographic and lifestyle characteristics, subjects with the highest consumption of ultra-processed foods (fourth quartile of % energy intake from ultra-processed foods) had 0.61 kg/m
higher body mass index (BMI; 95% confidence interval CI 0.23-0.99,
-trend 0.0047), 1.34 cm higher waist circumference (WC; 95% CI 0.35-2.34,
-trend 0.0146), 51% higher odds of being obese (BMI > 25 kg/m
; odds ratio OR 1.51, 95% CI 1.14-1.99,
-trend 0.0037), and 64% higher odds of abdominal obesity (men: WC ≥ 90 cm, women: WC ≥ 85 cm; OR 1.64, 95% CI 1.24-2.16,
-trend 0.0004) than those with the lowest consumption (first quartile) among women. However, no association was found in men. These findings provide evidence that high consumption of ultra-processed foods is positively associated with obesity in Korean women. Further studies with a large-scale cohort or intervention trial are needed to identify the mechanism of associations between consumption of ultra-processed foods and health-related outcomes including obesity in Korea.
The influence of alcohol consumption on the association of protein intake with muscle mass was assessed using data from the Korean Genome and Epidemiology Study. Dietary protein intakes of 4412 ...middle-aged participants with normal baseline muscle mass were assessed using a semi-quantitative Food Frequency Questionnaire, and baseline alcohol consumption data (e.g., frequency and amount) were collected using a structured questionnaire. The skeletal muscle mass index (SMI), defined as the weight-adjusted skeletal muscle mass, was measured using multi-frequency bioelectrical impedance analyses every 2 years until the study endpoint. Low muscle mass was defined as a SMI <2 standard deviations below the sex-specific normal mean for a young reference group. During a 12-year follow-up, 395 subjects developed a low SMI. After multivariate adjustments, high protein intake (≥1.2 g/kg body weight (BW)) was shown to reduce the risk of low SMI development in both men (hazard ratio (HR): 0.24; 95% confidence interval (CI): 0.12, 0.51;
for trend < 0.001) and women (HR: 0.29; 95% CI: 0.16, 0.53;
for trend < 0.001), compared with low protein intake (<0.8 g/kg BW). Alcohol consumption attenuated the protective influence of protein intake against low SMI development in women (HR: 0.64; 95% CI: 0.18, 2.25;
for trend = 0.478). Among the total subjects, heavy drinkers with high protein intake were not significantly associated with the development of a low SMI (HR: 0.20; 95% CI: 0.03, 1.50;
= 0.117). Additional research should clarify the dose-response effects of alcohol consumption on muscle mass relative to daily protein intake.
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. 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. 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). 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.
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