Validation Study of the Estimated Glycemic Load Model Using Commercially Available Fast Foods.

The recent popularization of low-glycemic foods has expanded interest in glycemic index (GI) not only among diabetic patients but also healthy people. The purpose of this study is to validate the estimated glycemic load model (eGL) developed in 2018. This study measured the glycemic load (GL) of 24 fast foods in the market in 20 subjects. Then, the transportability of the model was assessed, followed by an assessment of model calibration and discrimination based on model performance. The transportability assessment showed that the subjects at the time of model development are different from the subjects of this validation study. Therefore, the model can be described as transportable. As for the model's performance, the calibration assessment found an x 2 value of 11.607 and a p-value of 0.160, which indicates that the prediction model fits the observations. The discrimination assessment found a discrimination accuracy exceeding 0.5 (57.1%), which confirms that the performance and stability of the prediction model can be discriminated across all classifications. The correlation coefficient between GLs and eGLs measured from the 24 fast foods was statistically significant at 0.712 (p < 0.01), indicating a strong positive linear relationship. The explanatory powers of GL and eGL was high at 50.7%. The findings of this study suggest that this prediction model will greatly contribute to healthy food choices because it allows for predicting blood glucose responses solely based on the nutrient content labeled on the fast foods.

Development of a Prediction Model to Estimate the Glycemic Load of Ready-to-Eat Meals.

The glycemic index (GI) and glycemic load (GL) of a single food item has been used to monitor blood glucose level. However, concerns regarding the clinical relevance of the GI or GL have been raised on their applicability to a combination of several foods consumed as meal. This study aimed to investigate the glycemic response after consuming commercially purchased ready-to-eat meal and to develop the GL prediction formula using the composition of nutrients in each meal. Glycemic responses were measured in healthy adults with various mixed meals comprising approximately 25 g, 50 g, and 75 g of carbohydrates. After fasting, participants consumed test meals, and the glycemic response was measured for a subsequent 120 min. The GI and GL values for mixed meals were calculated as area under curve for each participant. For the prediction formula, 70 mixed meals were analyzed, of which the GI and GL values of 64 participants were used. The prediction formula produced was as follows: GL = 19.27 + (0.39 × available carbohydrate) - (0.21 × fat) - (0.01 × protein2) - (0.01 × fiber2). We hope that this prediction formula can be used as a useful tool to estimate the GL after consuming ready-to-eat meals.

Association between Self-Reported Sleep Duration and Dietary Nutrients in Korean Adolescents: A Population-Based Study.

(1) Background: Adolescence is a transient period from childhood to adulthood, which is characterized by rapid physical growth and psychological changes, including sleep. Because the relationship between insufficient sleep and obesity has been observed in children and adults, the potential links between sleep, dietary intake, and nutrition have received increased attention. We aimed to examine the association of sleep duration with dietary nutrients intake in South Korean adolescents; (2) Methods: This population-based, cross-sectional study analyzed the data obtained from the Korea National Health and Nutrition Examination Survey between 2013 and 2015. Data related to 1422 adolescents aged 12-18 years (741 males and 681 females) were included in the analysis. Sleep duration was assessed using a self-reported questionnaire. Nutrient intake, including daily total energy intake, was assessed with a 24-h dietary recall questionnaire; (3) Results: Most males (84.4%) and females (86.4%) reported < 9 h of sleep per night. Short sleep duration was inversely associated with body mass index and obesity in both sexes. We found that higher intake of fiber and lower intake of sodium were associated with longer sleep duration (P < 0.05). When comparing the intake above and below the estimated average requirements (EAR), the difference in sleep duration was significant in the group that consumed vitamins B1 and C below EAR; (4) Conclusions: The findings of this study indicate that sleep duration can be associated with intake of some nutrients, which may also be associated with obesity in adolescents. Therefore, it is possible to prevent obesity and its complications by controlling the sleep duration and intake of nutrients of adolescents.

Dietary and Health Characteristics of Korean Adults According to the Level of Energy Intake from Carbohydrate: Analysis of the 7th (2016-2017) Korea National Health and Nutrition Examination Survey Data.

The purpose of this study was to examine the association between the level of energy intake from carbohydrate and the dietary and health characteristics among Korean adults. We examined the diet quality and health conditions of Korean adults by segmenting them into eight groups according to the level of energy intake from carbohydrate (<45%, 45-50%, 50-55%, 55-60%, 60-65%, 65-70%, 70-75%, and >75%). From the data of the 7th (2016-2017) Korea National Health and Nutrition Examination Survey (KNHANES), 7566 subjects aged 19 to 64 years were analyzed. Diet quality was much lower in the groups whose energy intake from carbohydrate was <50% or >65%, compared to the groups whose energy intake from carbohydrate was 50-65%. Hypertension or low HDL-cholesterolemia was associated with low (<45%) or high (>70%) energy intake from carbohydrate. We found no considerable difference in the diet quality and health conditions between the groups whose energy intake from carbohydrate was 50-55% and 55-65%. In conclusion, it is suggested to expand the current acceptable macronutrient distribution range (AMDR) for carbohydrate for Korean adults (i.e., 55% to 65%) to include 50-55%.

Effect of nutrient composition in a mixed meal on the postprandial glycemic response in healthy people: a preliminary study.

BACKGROUND/OBJECTIVES: The glycemic index (GI) is a measure of the postprandial glucose response (PPGR) to food items, and glycemic load (GL) is a measure of the PPGR to the diet. For those who need to maintain a healthy diet, it is beneficial to regulate appropriate levels of blood glucose. In reality, what influences the meal GI or GL depends on the macronutrient composition and the physical chemistry reactions in vivo. Thus, we investigated whether different macronutrients in a meal significantly affect the PPGR and the validity of calculated GI and GL values for mixed meals. SUBJECTS/METHODS: 12 healthy subjects (6 male, 6 female) were recruited at a campus setting, and subjects consumed a total of 6 test meals one by one, each morning between 8:00 and 8:30 am after 12 h of fasting. PPGR was measured after each consumed meal and serial finger pricks were performed at indicated times. Test meals included 1) 68 g oral glucose, 2) 210 g rice, 3) rice plus 170 g egg white (RE), 4) rice plus 200 g bean sprouts (RS), 5) rice plus 10 g oil (RO), and 6) rice plus, egg white, bean sprouts, and oil (RESO). The incremental area under the curve (iAUC) was calculated to assess the PPGR. Mixed meal GI and GL values were calculated based on the nutrients the subjects consumed in each of the test meals. RESULTS: The iAUC for all meals containing two macronutrients (RS, RO, or RE) were not significantly different from the rice iAUC, whereas, the RESO iAUC (2,237.5 ± 264.9) was significantly lower (P < 0.05). The RESO meal's calculated GI and GL values were different from the actual GI and GL values measured from the study subjects (P < 0.05). CONCLUSIONS: The mixed meal containing three macronutrients (RESO) decreased the PPGR in healthy individuals, leading to significantly lower actual GI and GL values than those derived by nutrient-based calculations. Thus, consuming various macronutrient containing meals is beneficial in regulating PPGR.

Association of eggs with dietary nutrient adequacy and cardiovascular risk factors in US adults.

OBJECTIVE: Whole eggs are rich sources of several micronutrients. However, it is not well known how egg consumption contributes to overall nutrient adequacy and how it may relate to CVD risk factors. Therefore, the present study aimed to determine how whole egg consumption contributes to nutrient intakes and to assess its association with CVD risk factors in US adults. DESIGN: Cross-sectional study. SETTING: The study was conducted using data from the National Health and Nutrition Examination Survey (NHANES) 2003-2012, a nationally representative survey of the US civilian population.ParticipantsAdults who completed two dietary recalls and provided information on relevant sociodemographic factors were included in the study (n 21 845). RESULTS: Approximately 73 % of adults were classified as whole egg consumers. Egg consumption was associated with greater intakes of protein, saturated fat, mono- and polyunsaturated fats, Fe, Zn, Ca, Se, choline, and several other vitamins and minerals. Egg consumption was associated with a higher likelihood of meeting or exceeding recommendations for several micronutrients. Egg intake was positively associated with dietary cholesterol consumption, but not with serum total cholesterol (TC) when adjusted for multiple potential confounders. In multiple linear regression analyses, TAG, TAG:HDL-cholesterol and TC:HDL-cholesterol were significantly lower with greater egg consumption. Egg consumption had no significant relationship with LDL-cholesterol or C-reactive protein, but was associated with higher BMI and waist circumference. CONCLUSIONS: Whole eggs are important dietary contributors of many nutrients and had either beneficial or non-significant associations with most CVD risk biomarkers examined.

Effect of TV food advertising restriction on food environment for children in South Korea.

Summary: This study attempted to determine the effects of restrictions on television (TV) food advertising on children's food environments in South Korea. It examined changes that occurred in the marketing mix of food companies following enactment of those restrictions. An on-line survey was conducted with marketers or R&D managers of 108 food companies. A questionnaire was used to inquire about changes that occurred in Product, Place, Price and Promotion as a result of the restrictions placed on TV food advertising. Analysis was performed on the data collected from the responding 63 food companies (58.3%). The results of their answers showed that among the four marketing mix components the restrictions exerted relatively stronger effects on Product. Effects were stronger on companies that produced foods within the product categories of Energy-Dense and Nutrient-Poor foods (EDNP companies) in comparison with companies that did not (non-EDNP companies). The restrictions exerted positive effects on EDNP companies with respect to compliance with labeling requirements and reinforcement of nutritional contents examination, as well as changes to products such as reducing unhealthy ingredients and fortifying nutrients. Overall, the results revealed the possibility that restrictions on TV food advertising could improve children's food environments by encouraging EDNP companies to make favorable product changes. On the one hand, the results also found that some food companies attempted to bypass the regulations by changing marketing channels from TV to others and by reducing product serving sizes. Thus, future measures should be implemented to prevent food companies from bypassing regulations and to control children's exposure to marketing channels other than TV.

Breakfast skipping and breakfast type are associated with daily nutrient intakes and metabolic syndrome in Korean adults.

BACKGROUND/OBJECTIVES: Emerging evidence shows that eating breakfast and breakfast types may be associated with health outcomes and dietary intakes in various populations. The aim of this study was to investigate the association between breakfast types in Korean adults with their daily nutrient intakes and health outcomes. SUBJECTS/METHODS: A total of 11,801 20- to 64-year-old adults (age 42.9 ± 11.8 yrs [mean ± standard error of the mean]; male 41.1%, female 58.9%) in 2007-2009 Korean National Health and Nutrition Survey data were divided into 5 groups based on breakfast types in a 24-hr dietary recall: rice with 3 or more side dishes (Rice3+, 35.3%), rice with 0-2 side dishes (Rice0-2, 34.73%), noodles (1.56%), bread and cereal (6.56%), and breakfast skipping (21.63%). Daily nutrient intakes and the risk of metabolic syndrome were compared among five groups. RESULTS: Compared with Korean Recommended Nutrient Intake levels, the breakfast-skipping group showed the lowest intake level in most nutrients, whereas the Rice3+ group showed the highest. Fat intake was higher in the bread and noodle groups than in the other groups. When compared with the Rice3+ group, the odds ratios for the risk of obesity and metabolic syndrome were increased in the breakfast skipping, Rice0-2, and noodle groups after controlling for confounding variables. CONCLUSIONS: The rice-based breakfast group showed better nutritional status and health outcomes when eating with 3 or more side dishes. Nutrition education is needed to emphasize both the potential advantage of the rice-based, traditional Korean diet in terms of nutritional content and the importance of food diversity.

Impact of orange juice consumption on bone health of the U.S. population in the national health and nutrition examination survey 2003-2006.

Orange juice (OJ) fortified with calcium (Ca) and vitamin D has turned OJ into a readily available source of these nutrients for children and adults. However, the impact of OJ consumption on Ca and vitamin D adequacy and bone health has not been documented. The aim of this study was the evaluation of the contribution of 100% OJ consumption to dietary and serum Ca and vitamin D status, and bone health parameters in the U.S. population aged 4 years and older (n=13,971) using the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and 2005-2006. Food consumption data were coded to produce micronutrient intake values using the USDA Food and Nutrient Database for Dietary Studies 3.0. Serum concentrations of bone-related micronutrients and biomarkers, bone mineral density (BMD), and bone mineral content (BMC) were measured. Analysis of data was conducted using SAS software 9.2 and SUDAAN. OJ consumers showed higher intakes of bone-related micronutrients, compared with nonconsumers (P<.05). In addition, OJ consumers had higher serum Ca levels in adults (P<.01) and had a lower odds ratio for serum 25-hydroxyvitamin D3 <20 ng/mL in children (P<.05). OJ consumption was positively associated with femur BMD in children (P<.05) and with femur BMC in both children and adults (P<.05). In conclusion, OJ may be recommended as an effective dietary means of improving the status of Ca and vitamin D, acid-base balance, and of promoting bone health in children and adults.

Effects of exposure to television advertising for energy-dense/nutrient-poor food on children's food intake and obesity in South Korea.

The aim of this study was to determine the effect of television food advertising on participant food intake and risk of obesity. A total of 2419 children aged 11-13 years were selected from 118 elementary schools in South Korea. All participants completed a self-administered questionnaire with questions about height, weight, television viewing times, food preferences, and food intakes. To estimate actual exposure to food advertising, we asked participants to specify the times at which they usually watched television. We then collected data on the various types of food advertisement broadcast on five different television networks during those viewing times over the course of the previous 7 months. The amount of television watched and exposure to energy-dense/nutrient-poor (EDNP) food advertising were associated with an increased risk of being overweight or obese. Exposure to television advertising for EDNP food was also significantly associated with higher EDNP food preference and intake and lower fruit and vegetable intake. However, these relationships disappeared for all foods after adjusting for the overall amount of television watched. Although it was not possible to conclude that exposure to television advertising for EDNP food was associated with an increased risk of obesity, preference for EDNP foods, or overall food intake due to the strong comprehensive effects of television viewing time, there was a reason to believe the evidence of the effects of advertising in this study. Future longitudinal studies are needed to determine the exclusive effects of exposure to television advertising for EDNP food.

Dietary carotenoids are associated with cardiovascular disease risk biomarkers mediated by serum carotenoid concentrations.

Hyperlipidemia and elevated circulating C-reactive protein (CRP) and total homocysteine (tHcy) concentrations are cardiovascular disease (CVD) risk factors. Previous studies indicated that higher serum carotenoid concentrations were inversely associated with some of these biomarkers. However, whether dietary carotenoid intake is inversely associated with these CVD risk biomarkers is not well known. We assessed the associations between individual dietary carotenoid intake and CVD risk biomarkers and tested whether the serum carotenoid concentrations explain (mediate) or influence the strength of (moderate) the associations, if any association exists. Dietary data collected from 2 24-h dietary recalls and serum measurements in adult men (n = 1312) and women (n = 1544) from the NHANES 2003-2006 were used. Regression models designed for survey analysis were used to examine the associations between individual dietary carotenoids and log-transformed blood cholesterol, CRP, and tHcy. The corresponding individual serum carotenoid concentration was considered as mediator (and moderator if applicable). After adjustment for covariates, significant inverse associations with LDL cholesterol were observed for dietary ß-carotene (P < 0.05) and lutein + zeaxanthin (P < 0.001), and with tHcy for dietary ß-carotene (P < 0.05), lycopene (P < 0.05), and total carotenoids (P < 0.05). Dietary lutein + zeaxanthin intake was also positively associated with HDL cholesterol concentrations (P < 0.01). Most of these associations were null after additional adjustment for corresponding serum carotenoid concentrations, indicating the complete mediation effects of serum carotenoids. Serum ß-carotene significantly moderated the associations between dietary ß-carotene and CRP (P-interaction < 0.05), and quartile 4 of dietary ß-carotene was associated with lower CRP concentrations only among participants with serum ß-carotene > 0.43 µmol/L. In this population-based cross-sectional study, serum carotenoids were mediators of dietary carotenoids and CVD risk biomarker associations. Serum ß-carotene was also a moderator of the dietary ß-carotene and CRP association. These findings may help in the design of future intervention studies on dietary carotenoids in the prevention of CVD.

Validation of self-reported height and weight in fifth-grade Korean children.

Height and weight are important indicators to calculate Body Mass Index (BMI); measuring height and weight directly is the most exact method to get this information. However, it is ineffective in terms of cost and time on large population samples. The aim of our study was to investigate the validity of self-reported height and weight data compared to our measured data in Korean children to predict obese status. Four hundred twenty-two fifth-grade (mean age 10.5 ± 0.5 years) children who had self-reported and measured height and weight data were final subjects for this study. Overweight/obese was defined as a BMI of or above the 85th percentile of the gender-specific BMI for age in the 2007 Korean National Growth Charts or a BMI of 25 or higher (underweight : < 5th, normal : ≥ 5th to < 85th, overweight : ≥ 85th to < 95th). The differences between self-reported and measured data were tested using paired t-test. Differences based on overweight/obese status were tested using analysis of variance (ANOVA) and linear trends. Pearson's correlation and Cohen's kappa were tested to examine agreements between the self-reported and measured data. Although measured and self-reported height, weight and BMI were significantly different and children tended to overreport their height and underreport their weight, the correlation between the two methods of height, weight and BMI were high (r = 0.956, 0.969, 0.932, respectively; all P < 0.001), and both genders reported their overweight/non-overweight status accurately (Cohen's kappa = 0.792, P < 0.001). Although there were differences between the self-reported and our measured methods, the self-reported weight and height was valid enough to classify overweight/obesity status correctly, especially in non-overweight/obese children. Due to bigger underestimation of weight and overestimation of height in obese children, however, we need to be aware that the self-reported anthropometric data were less accurate in overweight/obese children than in non-overweight/obese children.

Orange juice, a marker of diet quality, contributes to essential micronutrient and antioxidant intakes in the United States population.

OBJECTIVE: To evaluate the impact of 100% orange juice (OJ) on the healthy diet and micronutrient intakes of the United States population. METHODS: Cross-sectional study of 13,971 people in the United States aged ≥ 4 years using 2 24-hour diet recalls from the National Health and Nutrition Examination Survey, 2003-2006. RESULTS: Consumption of OJ was higher among 4- to 8-year-old children, older adults (> 50 y old), non-Hispanic blacks, those with lower body mass index, those of lower income level, nonsmokers, dietary supplement users, and those participating in regular exercise (P < .05). Consumption of OJ was positively associated with the percentage of participants meeting MyPyramid recommendations for fruit consumption. Increased OJ consumption was correlated with increased daily intakes of certain micronutrients and antioxidants (P < .05). Percentages of participants with intakes below Estimated Average Requirements for these micronutrients decreased with increased OJ consumption (P < .001). CONCLUSIONS AND IMPLICATIONS: The implicated nutritional and potential health benefits of OJ warrant further investigation in clinical research studies.

Dietary antioxidant capacity is associated with improved serum antioxidant status and decreased serum C-reactive protein and plasma homocysteine concentrations.

PURPOSE: To investigate the associations of dietary TAC from diet and supplements with serum antioxidant concentrations and serum C-reactive protein (CRP) and plasma total homocysteine (tHcy) in US adults. METHODS: This was a cross-sectional study. Food consumption data, serum antioxidant levels, and serum CRP and Plasma tHcy concentrations of 4,391 US adults aged ≥19 years in the National Health and Nutrition Examination Survey 2001-2002 were analyzed. The USDA flavonoid and proanthocyanidin databases and dietary supplement data as well as antioxidant capacities of 43 antioxidants were also utilized. RESULT: Serum CRP and plasma tHcy concentrations were higher in older adults, smokers, and those with lower non-leisure time physical activity levels (P < 0.05). Energy-adjusted daily total antioxidant capacity (TAC) from diet and supplements was positively associated with serum vitamin E and carotenoid concentrations (P < 0.05). Adjusted odds ratio (OR) for plasma tHcy >13 µmol/L significantly decreased across quartiles of TAC from diet and supplements (Q1 = 2.18 (1.56-2.77); Q2 = 1.30 (1.00-2.07); Q3 = 1.34 (0.84-2.28); Q4 = 1.00; P for linear trend <0.001). A negative trend across quartiles of TAC from diet and supplements was also observed in OR for serum CRP ≥3 mg/L (Q1 = 1.26 (0.97-1.70); Q2 = 1.21 (0.91-1.66); Q3 = 0.97 (0.80-1.24); Q4 = 1.00; P for linear trend <0.05). CONCLUSIONS: These findings indicated that dietary TAC provided an integrated conceptual tool in assessing serum antioxidants and investigating the associations between antioxidant intake and CVD risk. The implicated applicability of dietary TAC needs further validation in prospective cohort studies.

Restriction of television food advertising in South Korea: impact on advertising of food companies.

The association between exposure to television (TV) food advertising and children's dietary habits has been well established in previous studies. However, the efficacy of restrictions on TV food advertising in the prevention of childhood obesity remains controversial. The South Korean government has recently enforced a regulation, termed the Special Act on Safety Management of Children's Dietary Life, which restricts TV advertising of energy-dense and nutrient-poor (EDNP) foods targeting children. This study aimed to determine the impact of this regulation by examining changes in the TV advertising practices of South Korean food companies since the scheduled enforcement date of January 2010. The total advertising budget, number of advertisement placements and gross rating points (GRPs) for advertisements on EDNP foods aired on the five representative TV channels in South Korea were compared and analyzed for the year before and after January 2010. After January 2010, the total adverting budget, number of advertisement placements and GRPs decreased during regulated hours. Even during non-regulated hours, a significant decline was noticed in the number of advertisement placements and GRPs. The total advertising budget for non-EDNP foods increased, whereas that for EDNP foods decreased at a higher rate in addition to a drop in its percentage share. These results suggest positive changes in TV advertising practices of food companies because of the regulation, thereby lowering children's exposure to TV advertising of EDNP foods and promoting a safer environment that may facilitate child health improvement in South Korea.

Serum immunoglobulin E (IgE) levels and dietary intake of Korean infants and young children with atopic dermatitis.

Atopic dermatitis (AD) has become a serious epidemic in Korean children. We aimed to investigate the association between vitamin C, E and other nutrients, and serum total IgE/specific IgE levels in children with AD. A total of 119 children (0-24 mo) diagnosed with AD were recruited for this cross-sectional study from a medical center in Seoul. A 24 h recall was used to assess dietary intakes. Serum total and six food-allergen specific IgE levels were measured by CAP-FEIA. Serum vitamin E was also measured but only in 25 out of the total 119 participants. Multiple linear regression analysis was performed to estimate the coefficients between serum IgE levels and dietary intake as well as serum vitamin E. Serum vitamin E levels showed a significantly inverse association with serum total IgE and all specific IgE levels (P < 0.05). Fat intake was inversely related with specific-IgEs for egg whites, milk, buck wheat, soy, and peanuts (P < 0.05). Positive associations were found between carbohydrate (CHO) intake and total IgE and specific IgEs to egg whites, milk, soy, and peanuts (P < 0.05). Vitamin C, E and n-3/n-6 fatty acids were not related with serum total IgE and specific IgE levels except for the association between buck wheat and vitamin E. In addition, there were no significant differences between males and females in dietary intake and serum IgE levels by student's t-test. Although dietary vitamin E showed no association with serum IgE levels, serum vitamin E drew a significant inverse relationship with serum IgE levels. The evidence seems to suggest that vitamin E may possibly lower total and specific-IgEs in children with AD, and that it is important to maintain a relatively high serum vitamin E level in children with AD.

Impact of orange juice consumption on macronutrient and energy intakes and body composition in the US population.

OBJECTIVE: The present study evaluated the contribution of 100 % orange juice (OJ) consumption to the intakes of macronutrients and energy and its impact on body composition. DESIGN: A cross-sectional study was conducted. The main exposure was OJ consumption based on two non-consecutive 24 h diet recalls. Macronutrient and energy intakes and body composition parameters were outcome measures. All statistical analyses were carried out using SAS and SUDAAN statistical software packages to allow for multistage sample designs. SETTING: The US population and its subgroups. SUBJECTS: The US population aged ≥4 years (n 13 971) from the National Health and Nutrition Examination Survey 2003-2006, conducted by the National Center for Health Statistics. RESULTS: In this US population, OJ consumers had lower BMI and healthier lifestyle behaviours (including lower alcohol consumption and smoking as well as higher exercise level) than non-consumers (P < 0.05). After adjusting for covariates, OJ consumers had higher daily intakes of carbohydrate, total sugar, total fat and energy than non-consumers (P < 0.01). However, these linear trends still remained even after OJ was removed from the food list of items consumed. Adult OJ consumers had lower BMI, waist circumference and percentage body fat than non-consumers (P < 0.01), as well as lower odds ratio for overweight and obesity (P < 0.01). These effects were not seen in children and adolescents, where there was no significant difference in BMI, waist circumference and percentage body fat in OJ consumers compared with non-consumers. CONCLUSIONS: OJ consumption was associated with healthier body composition in adults; while there were no significant associations between OJ consumption and body composition in children and adolescents.

Antioxidant intake from diet and supplements and elevated serum C-reactive protein and plasma homocysteine concentrations in US adults: a cross-sectional study.

OBJECTIVE: To investigate the association of antioxidant intakes from diet and supplements with elevated blood C-reactive protein (CRP) and homocysteine (Hcy) concentrations. DESIGN: A cross-sectional study. The main exposures were vitamins C and E, carotene, flavonoid and Se intakes from diet and supplements. Elevated blood CRP and Hcy concentrations were the outcome measures. SETTING: The US population and its subgroups. SUBJECTS: We included 8335 US adults aged ≥19 years from the National Health and Nutrition Examination Survey 1999-2002. RESULTS: In this US population, the mean serum CRP concentration was 4·14 (95 % CI 3·91, 4·37) mg/l. Intakes of vitamins C and E and carotene were inversely associated with the probability of having serum CRP concentrations >3 mg/l in multivariate logistic regression models. Flavonoid and Se intakes were not associated with the odds of elevated serum CRP concentrations. The mean plasma Hcy concentration was 8·61 (95 % CI 8·48, 8·74) µmol/l. Intakes of vitamins C, E, carotenes and Se were inversely associated with the odds of plasma Hcy concentrations >13 µmol/l after adjusting for covariates. Flavonoid intake was not associated with the chance of elevated plasma Hcy concentrations. CONCLUSIONS: These results suggest that high antioxidant intake is associated with lower blood concentrations of CRP and Hcy. These inverse associations may be among the potential mechanisms for the beneficial effect of antioxidant intake on CVD risk mediators in observational studies.

Estimation of total antioxidant capacity from diet and supplements in US adults.

Given the importance of dietary antioxidants in reducing the risks of chronic diseases, the present study aimed to estimate the intake of total antioxidant capacity (TAC) from diet and dietary supplements of US adults. We utilised the US Department of Agriculture flavonoid and proanthocyanidin databases, dietary supplement data and food consumption data of 4391 US adults aged 19+ years in the National Health and Nutrition Examination Survey 2001-2. In order to convert the intake data of individual antioxidant compounds to TAC values, the vitamin C equivalent (VCE) of forty-three antioxidant nutrients measured previously was also applied. Daily TAC averaged 503.3 mg VCE/d (approximately 75 % from diet and 25 % from supplements). The energy-adjusted daily TAC level from diet and supplements was higher in women (except for carotenoids), older adults, Caucasian (except for carotenoids), non-alcohol consumers (for vitamin E and proanthocyanidins), subjects with higher income (except for carotenoids) and higher exercise levels than their counterparts (P < 0.05). TAC was positively associated with daily consumption of fruits and fruit juices, vegetables and vegetable products, beverages, wines and teas (P < 0.001). Teas, dietary supplements, and fruits and fruit juices were the major sources of dietary TAC of the US population (28, 25 and 17 %, respectively), while the contribution of vegetables and vegetable products to TAC was minimal ( < 2 %). The present study indicates that antioxidant intake from various diet and supplements contributes to TAC status. TAC levels are different in sociodemographic subgroups of the US population. The relationship between TAC intake and risks of chronic disease warrants further investigation.