[Show abstract][Hide abstract]ABSTRACT: Background/objectives:
A healthy diet has been reported to be associated with physical development, cognition and academic performance, and personality during adolescence. This study was performed to investigate the relationships among milk consumption and academic performance, learning motivation and strategies, and personality among Korean adolescents.
The study was divided into two parts. The first part was a survey on the relationship between milk consumption and academic performance, in which intakes of milk and milk products and academic scores were examined in percentiles among 630 middle and high school students residing in small and medium-sized cities in 2009. The second part was a survey on the relationships between milk consumption and learning motivation and strategy as well as personality, in which milk consumption habits were collected and Learning Motivation and Strategy Test (L-MOST) for adolescents and Total Personality Inventory for Adolescents (TPI-A) were conducted in 262 high school students in 2011.
In the 2009 survey, milk and milk product intakes of subjects were divided into a low intake group (LM: ≤ 60.2 g/day), medium intake group (MM: 60.3-150.9 g/day), and high intake group (HM: ≥ 151.0 g/day). Academic performance of each group was expressed as a percentile, and performance in Korean, social science, and mathematics was significantly higher in the HM group (P < 0.05). In the 2011 survey, the group with a higher frequency of everyday milk consumption showed significantly higher "learning strategy total," "testing technique," and "resources management technique" scores (P < 0.05) in all subjects. However, when subjects were divided by gender, milk intake frequency, learning strategy total, class participation technique, and testing technique showed significantly positive correlations (P < 0.05) in boys, whereas no correlation was observed in girls. Correlations between milk intake frequency and each item of the personality test were only detected in boys, and milk intake frequency showed positive correlations with "total agreeability", "organization", "responsibility", "conscientiousness", and "intellectual curiosity" (P < 0.05).
Intakes of milk and milk products were correlated with academic performance (Korean, social science, and mathematics) in Korean adolescents. In male high school students, particularly, higher milk intake frequency was positively correlated with learning motivation and strategy as well as some items of the personality inventory.
Full-text Article · Apr 2016 · Nutrition research and practice
[Show abstract][Hide abstract]ABSTRACT: DNA damages and antioxidant status was assessed after 8 weeks of purple grape juice supplementation in male smokers depending on the glutathione S-transferase polymorphisms. Ninety-five smokers consumed 480 ml of purple grape juice for 8 weeks. The blood samples were collected before and after supplementation to measure lymphocyte DNA damages, plasma antioxidants, conjugated diene, and the erythrocyte antioxidant enzymes. The diastolic pressure, lymphocyte DNA damage, and plasma conjugated diene were significantly decreased but the plasma γ-tocopherol was increased in GSTM1-null genotype, while increased blood glutathione and decreased lymphocyte DNA damage were observed in GSTM1-present genotype. In case of GSTT1 on the other hand, the decrease in diastolic pressure and lymphocyte DNA damage was observed in both null types and present types, but the erythrocyte catalase activity was decreased in GSTT1-null type and the plasma vitamin C level was increased in GSTT1-present type, suggesting that, the antioxidant effect of grape juice was greater in GSTT1-present type compared to GSTT1-null type. The intakes of 8-week purple grape juice affected diastolic blood pressures, DNA damage reductions and antioxidant status in smokers, mainly greater in GSTM1-null type and GSTT1-present type.
Article · Feb 2015 · Journal of Clinical Biochemistry and Nutrition
[Show abstract][Hide abstract]ABSTRACT: Glutathione S-transferase (GST) forms a multigene family of phase II detoxification enzymes which are involved in the detoxification of reactive oxygen species. This study examines whether daily supplementation of kale juice can modulate blood pressure (BP), levels of lipid profiles, and blood glucose, and whether this modulation could be affected by the GSTM1 and GSTT1 polymorphisms.
84 subclinical hypertensive patients showing systolic BP over 130 mmHg or diastolic BP over 85 mmHg received 300 ml/day of kale juice for 6 weeks, and blood samples were collected on 0-week and 6-week in order to evaluate plasma lipid profiles (total cholesterol, triglyceride, HDL-cholesterol, and LDL-cholesterol) and blood glucose.
Systolic and diastolic blood pressure was significantly decreased in all patients regardless of their GSTM1 or GSTT1 polymorphisms after kale juice supplementation. Blood glucose level was decreased only in the GSTM1-present genotype, and plasma lipid profiles showed no difference in both the GSTM1-null and GSTM1-present genotypes. In the case of GSTT1, on the other hand, plasma HDL-C was increased and LDL-C was decreased only in the GSTT1-present type, while blood glucose was decreased only in the GSTT1-null genotype.
These findings suggest that the supplementation of kale juice affected blood pressure, lipid profiles, and blood glucose in subclinical hypertensive patients depending on their GST genetic polymorphisms, and the improvement of lipid profiles was mainly greater in the GSTT1-present genotype and the decrease of blood glucose was greater in the GSTM1-present or GSTT1-null genotypes.
Full-text Article · Feb 2015 · Nutrition research and practice
[Show abstract][Hide abstract]ABSTRACT: BACKGROUND/OBJECTIVES
The traditional Korean diet is plant-based and rich in antioxidants. Previous studies have investigated the potential health benefits of individual nutrients of Korean foods. However, the cumulative effects of a Korean diet on inflammation remain poorly understood. Therefore, the aim of this study was to investigate the anti-inflammatory effects of a plant-based Korean diet.
Using data from the Fifth Korean National Health and Nutrition Examination Survey, 75 individual plant food items were selected which represent over 1% of the total diet intake of the Korean diet. These items were classified into ten different food groups, and the vegetable (Veg) and fruit (Fruit) groups were studied based on their high antioxidant capacity. For comparison, a mixture of all ten groups (Mix) was prepared. To produce a model of inflammation with which to test these Veg, Fruit, and Mix plant-based Korean food extracts (PKE), RAW264.7 macrophages were treated with lipopolysaccharide (LPS).
Levels of nitric oxide (NO) and prostaglandin E2 (PGE2), as well as protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were found to be lower following PKE treatment. Furthermore, PKE treatment was found to suppress tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) via the nuclear transcription factor kappa-B (NF-κB) signaling pathway. Overall, the Mix group exhibited the greatest anti-inflammatory effects compared with Veg and Fruit PKE group.
Inhibition of LPS-induced pro-inflammatory mediators by the PKE tested was found to involve an inhibition of NF-kB activation. Moreover, PKE tested have the potential to ameliorate various inflammation-related diseases by limiting the excessive production of pro-inflammatory mediators.
Full-text Article · Jun 2014 · Nutrition research and practice
[Show abstract][Hide abstract]ABSTRACT: PEKs do not affect cell viability in RAW264.7 macrophages. Cells were treated with various doses of each PEK (2, 4, or 8 mg/ml) for 24 h. The cell numbers were counted using a hemocytometer after staining with trypan blue for enumerating viable cells. Stained and unstained cells were counted and the proportion of surviving cells was calculated for cell viability. One-way ANOVA was implemented using Tukey's post-hoc test (α = 0.05). Mix PKE (A), Veg PKE (B), and Fruit PKE (C) are shown. Mix, an extract containing all ten food groups; Veg, vegetable PKE; Fruit, fruit PKE.
[Show abstract][Hide abstract]ABSTRACT: The objective of this study was to measure and/or estimate the total antioxidant capacity of the Korean diet.
Eighty-one plant foods that were expected to exhibit rather high antioxidant activities were selected from the Korean diet using the Fifth Korean National Health and Nutrition Survey (KNHANES V). These foods were categorized into 11 food groups: cereals, potatoes, legumes, nuts, vegetables, kimchies, mushrooms, fruits, fruit juices, sea weeds, and oils. The foods were mixed in the proportions specified in traditional Korean recipes and analyzed. The measured indicators for antioxidant capacities were total phenolics, 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC), and Trolox equivalent antioxidant capacity (TEAC).
Total phenolics were high in the fruit juices, nuts, vegetables, and fruits; and the average DPPH, ORAC, and TEAC values were high in the vegetables, fruits, fruit juices, and nuts. The correlation coefficient between the content of total phenolics of each food and the in vitro antioxidant capacity was relatively high at 0.851. The intake of total phenolics per capita per day in the Republic of Korea was estimated to be 127 mg. The total dietary antioxidant capacity (TDAC) values, which were obtained from the total antioxidant capacity of each food, taking into account the intake of each food, were 20,763, 54,335, and 876.4 µmol of Trolox equivalents using the DPPH, ORAC, and TEAC methods, respectively. The food group that contributed the most to the Korean TDAC was cereals at 39.7%, followed by fruits and vegetables at 27.8% and 13.9%, respectively. The contribution of legumes, nuts, fruit juices, and mushrooms was quite minimal at less than 2% each.
The content of total phenolics and the antioxidant capacity of the Korean diet are significantly correlated and the high contributing food groups are cereals, fruits, and vegetables.
Full-text Article · Apr 2014 · Nutrition research and practice
[Show abstract][Hide abstract]ABSTRACT: Abstract This study was performed to investigate the relationship between dietary factors and asthma in a representative population-based sample of 19,659 men and women, aged 19-64 years, using data from the fourth and fifth Korean National Health and Nutrition Examination Survey (KNHANES), 2007-2011. The presence of asthma was based on self-reported physician diagnosis of asthma in the Health Interview Surveys. Food intake was estimated by trained interviewers using a 24-h recall method. The prevalence of asthma in Korean adults was 2.4%. Adults with asthma consumed fewer amounts of kimchi (P=.0444) and fish (P=.0175) but had a higher cereal intake than those without asthma (P=.0056). Multiple logistic regression analysis after controlling for confounding factors showed a significant inverse relationship between kimchi consumption and the prevalence of asthma [odds ratio (95% confidence interval) for subjects consuming 1 to <2 servings (40-79.9 g), 2 to <3 servings (80-119.9 g), and ≥3 servings (≥120 g), relative to those consuming <1 serving (<40 g): 0.726 (0.534-0.987), 0.506 (0.348-0.736), and 0.678 (0.502-0.916), respectively; P for trend=0.0131]. These results warrant future studies to explore the mechanisms responsible for the association between kimchi consumption and asthma.
[Show abstract][Hide abstract]ABSTRACT: To investigate the associations of behavioural problems with dietary patterns and weight status in young children.
We assessed poor social skills and behavioural problems with a seventy-six-item Preschool and Kindergarten Behavior Scale (PKBS) and found three dietary patterns ('Korean healthy', 'animal foods' and 'sweets') in food/food group intake data assessed by an FFQ and analysed using factor analysis. Multiple logistic regression analyses were used to assess the association of diet and weight status with behaviour.
Pre-schools in the metropolitan areas of Korea.
A total of 1458 children (mean age 5·2 (sd 0·9) years) from the Practical Approach for Better Maternal and Child Nutrition and Health Study conducted from 2001 to 2005.
The 'Korean healthy' pattern showed a significant inverse association with poor social skills in the second highest quartile group (OR = 0·42; 95 % CI 0·21, 0·82) compared with the lowest quartile group for boys. For girls, the 'sweets' pattern was associated with a greater risk of poor social skills (OR = 3·41; 95 % CI 1·29, 9·01 at Q4 v. Q1) and problem behaviours (OR = 2·80; 95 % CI 1·05, 7·43 at Q4 v. Q1). Regarding weight status, both underweight and overweight boys had a higher risk of poor social skills than normal-weight boys.
Dietary patterns and weight status are important indicators for the behaviour of young children. Healthy and unhealthy dietary patterns, underweight and overweight status, and gender differences should thus be considered for further studies.
Full-text Article · Nov 2013 · Public Health Nutrition
[Show abstract][Hide abstract]ABSTRACT: This study was conducted to investigate the relationship among the current status of calcium intake from milk and milk products, physical growth and bone mineral density in 664 male and female middle school and high school students aged 15-17 years. In the study, the current status of calcium intake from milk and milk products was analyzed, and the height, body composition, and bone mineral density of the right heel bone (calcaneus) were measured. The daily calcium intake of milk and milk products was calculated as the 'dairy equivalent of calcium', which is the calcium content in 200 mL of white milk. The cutoffs of tertiles of the dairy equivalent of calcium were calculated and then the subjects were categorized into 3 groups according to the tertiles, Q1 group (lower intake group), Q2 group (middle intake group) and Q3 group (upper intake group). The daily calcium intake of milk and milk products in Q1, Q2 and Q3 groups was 16.2 mg, 99.7 mg, and 284.0 mg, respectively, and the ratio of milk and milk product consumption to the daily total calcium intake was 5.4%, 27.4%, and 49.7%, respectively. The ratio of total calcium intake to the daily recommended intake in study subjects was 30.5% in Q1, 42.3% in Q2, and 60.7% in Q3, with significant differences (P < 0.05). Height, body weight, BMI, and % of body fat in three tertile groups (Q1, Q2 and Q3) were not significantly different. However, the T scores for bone mineral density in female students in three tertile groups (Q1, Q2 and Q3) was significantly different (P < 0.05). The study showed that the intake of milk and milk products in adolescents, particularly in girls, can improve the bone mineral density without increasing body weight, and thus confirmed that milk intake is important in adolescence.
Full-text Article · Aug 2013 · Nutrition research and practice
[Show abstract][Hide abstract]ABSTRACT: This study was conducted in order to investigate the association between hypertension and oxidative stress-related parameters and to evaluate these parameters in subclinical hypertensive patients and normotensive subjects living in Korea. We attempted to determine whether oxidative stress-related parameters would differ between two groups of 227 newly-diagnosed, untreated (systolic blood pressure (BP) ≥ 130 mmHg and diastolic BP ≥ 85 mmHg) and 130 normotensive subjects (systolic BP < 120 mmHg and diastolic BP < 80 mmHg). General characteristics of the subjects were collected using a simple questionnaire. From subjects' blood, degree of DNA damage in lymphocytes, the activities of erythrocyte superoxide dismutase, catalase, and glutathione peroxidase, level of plasma total radical-trapping antioxidant potential (TRAP), glutathione, and anti-oxidative vitamins, as well as plasma lipid profiles and conjugated diene (CD) were analyzed. Evaluation of the associations of oxidative stress-related parameters with blood pressure of the subjects was performed using Pearson partial correlation and multivariate logistic regression analysis after adjusting for confounding factors. Several oxidative stress-related parameters were higher in subclinical hypertensive patients than in normotensive subjects. Plasma levels of α-tocopherol, β-carotene, TRAP, and activity of GSH-px were significantly lower in subclinical hypertensive patients than in normotensive subjects. Increased levels of DNA damage, lipid peroxidation, triglyceride, total cholesterol, and LDL-cholesterol were observed in subclinical hypertensive patients. These results confirm an association between blood pressure and oxidative stress-related parameters and suggest that the pathogenic role of oxidative stress in hypertension might be significant.
Article · Apr 2013 · The Korean Journal of Nutrition
[Show abstract][Hide abstract]ABSTRACT: This study investigated the effects of magnetized water supplementation on blood glucose, DNA damage, antioxidant status, and lipid profiles in streptozotocin (STZ)-induced diabetic rats. There were three groups of 4-week-old male Sprague-Dawley rats used in the study: control group (normal control group without diabetes); diabetes group (STZ-induced diabetes control); and magnetized water group (magnetized water supplemented after the induction of diabetes using STZ). Before initiating the study, diabetes was confirmed by measuring fasting blood glucose (FBS > 200 dl), and the magnetized water group received magnetized water for 8 weeks instead of general water. After 8 weeks, rats were sacrificed to measure the fasting blood glucose, insulin concentration, glycated hemoglobin level, degree of DNA damage, antioxidant status, and lipid profiles. From the fourth week of magnetized water supplementation, blood glucose was decreased in the magnetized water group compared to the diabetes group, and such effect continued to the 8th week. The glycated hemoglobin content in the blood was increased in the diabetes group compared to the control group, but decreased significantly in the magnetized water group. However, decreased plasma insulin level due to induced diabetes was not increased by magnetized water supplementation. Increased blood and liver DNA damages in diabetes rats did significantly decrease after the administration of magnetized water. In addition, antioxidant enzyme activities and plasma lipid profiles were not different among the three groups. In conclusion, the supplementation of magnetized water not only decreased the blood glucose and glycated hemoglobin levels but also reduced blood and liver DNA damages in STZ-induced diabetic rats. From the above results, it is suggested that the long-term intake of the magnetized water over 8 weeks may be beneficial in both prevention and treatment of complications in diabetic patients.
Full-text Article · Feb 2013 · Nutrition research and practice
[Show abstract][Hide abstract]ABSTRACT: This pilot study was performed to produce data of the Children's Dietary Life Safety (CDLS) Index which is required by the Special Act on Safety Management of Children's Dietary Life and to evaluate the CDLS Index for 7 metropolitan cities and 9 provinces in Korea. To calculate the CDLS Index score, data regarding the evaluation indicators in the children's food safety domain and children's nutrition safety domain were collected from the local governments in 2009. For data regarding the indicators in the children's perception & practice domain, a survey was conducted on 2,400 5th grade children selected by stratified sampling in 16 local areas. Relative scores of indicators in each domain were calculated using the data provided by local governments and the survey, the weights are applied on relative scores, and then the CDLS Index scores of local governments were produced by adding scores of the 3 domains. The national average scores of the food safety domain, the nutrition safety domain and the perception and practice domain were 23.74 (14.67-26.50 on a 40-point scale), 16.65 (12.25-19.60 on a 40-point scale), and 14.88 (14.16-15.30 on a 20-point scale), respectively. The national average score of the CDLS Index which was produced by adding the scores of the three domains was 55.27 ranging 46.44-58.94 among local governments. The CDLS Index scores produced in this study may provide the motivation for comparing relative accomplishment and for actively achieving the goals through establishment of the target value by local governments. Also, it can be used as useful data for the establishment and improvement of children's dietary life safety policy at the national level.
Full-text Article · Dec 2012 · Nutrition research and practice
[Show abstract][Hide abstract]ABSTRACT: This study was performed to investigate the differences in food choice, nutrition labeling perceptions, and prevalence of obesity due to meal skipping in Korean elementary school children. A national survey was performed in 2010 to collect data on food intake frequency, understanding of nutrition labeling, and body mass index from 2,335 fifth grade students in 118 elementary schools selected from 16 metropolitan local governments by stratified cluster sampling. The data were analyzed using the SAS 9.1 and SUDAAN 10.0 packages. Students who consumed three meals for 6-7 days during the past week were classified into the regular meal eating (RM) group (n = 1,476) and those who did not were placed into the meal skipping (MS) group (n = 859). The daily intake frequency of fruits, vegetables, kimchi, and milk was significantly lower in the MS group compared to that in the RM group (P < 0.001), whereas the daily intake frequency of soft drinks and instant noodles (ramyeon) was significantly higher in the MS group than that in the RM group (P < 0.05). The MS group demonstrated a significantly lower degree of understanding with regard to nutrition labeling and high calorie foods containing low nutritional value than that in the RM group. The distribution of obesity based on the percentile criteria using the Korean growth chart was different between the MS and RM groups. The MS group (8.97%) had a higher percentage of obese subjects than that in the RM group (5.38%). In conclusion, meal skipping was related to poor food choice, low perception of nutrition labeling, and a high prevalence of obesity in Korean fifth grade children.
Full-text Article · Aug 2012 · Nutrition research and practice
[Show abstract][Hide abstract]ABSTRACT: The objective of this study was to develop and evaluate the construct validity of a Nutrition Quotient (NQ) for children. In a previous report (Kang, et al., 2012), the food behavior checklist for children's NQ, consisting of 19 items, was grouped into a 5-factor structure according to the exploratory factor analysis: balance, diversity, moderation, regularity, and practice. In this study, the construct validity of the NQ was assessed using a confirmatory factor analysis. Elementary school students (n = 1,393) from six large cities completed the NQ test. Indicator tests suggested an adequate model fit (goodness of fit index = 0.9613; adjusted GFI = 0.95; standardized root mean square residual = 0.0464; chi-square test statistics of < 0.001 p-value, 82.1), and item loadings were significant for all subscales (p < 0.05). The standardized path coefficients were used as the weights of the items. The NQ and the 5 factor scores of the student were calculated by the obtained weights of the questionnaire items. Logistic regression was applied to find the significant factors in order to affect a specific nutrient status. The receiver operation characteristic curve analyses were performed in order to find diagnostic cut-off points of the five factors. The food behavior checklist for children's NQ would be a handy and suitable instrument for evaluating dietary behaviors of Korean children.
Article · Jan 2012 · The Korean Journal of Nutrition
[Show abstract][Hide abstract]ABSTRACT: The objective of this study is to select a simple and easy measurable food behavior checklist for the development of Nutrition Quotient (NQ) for children, which reflects children's diet quality, as well as to evaluate the validity of the items in the food behavior checklist. The first 36 items in the checklist were established by an expert review, modifying the preliminary 50 items in the checklist, which had been selected by a literature review and the Korean National Health and Nutrition Examination Survey data. 341 children in 5th and 6th grades at an elementary school participated in a one-day dietary record survey, and later responded to 36 food behavior questions of the checklist. Pearson's correlation coefficients between the responses to the food behavior checklist items along with the mean nutrient intakes of the children were calculated. From the result, in which responses of food frequency and food behavior items showed certain association with the dietary record data, a second checklist with 22 items was selected. A survey was conducted by using the second checklist. 1,393 children in the 5th and 6th grades at 12 elementary schools in metropolitan cities, such as Seoul, Busan, Gwangju, Daegu, Daejeon, and Incheon, participated in the survey. Further, an exploratory factor analysis was performed. After the analysis, 19 items (10 items from food frequency and 9 items from food behavior) were finalized as the food behavior checklist items for the NQ. The final 19 food behavior checklist items were composed of 5 factors: 'Balance', 'Diversity', 'Moderation', 'Regularity', and 'Practice'. This study is a significant first trial to establish a comprehensive system for evaluating children's food habit and diet quality. This checklist might need continuous modification and revision reflecting the change of children's dietary life and the social environment.
Article · Jan 2012 · The Korean Journal of Nutrition
[Show abstract][Hide abstract]ABSTRACT: Folate deficiency and hyperhomocysteinemia are found in most patients with alcoholic liver disease. Oxidative stress is one of the most important mechanisms contributing to homocysteine (Hcy)-induced tissue injury. However it has not been examined whether exogenous administration of folic acid attenuates oxidative stress and hepatic toxicity. The aim of this study was to investigate the in vivo effect of folic acid supplementation on oxidative stress and hepatic toxicity induced by chronic ethanol consumption. Wistar rats (n = 32) were divided into four groups and fed 0%, 12%, 36% ethanol, or 36% ethanol plus folic acid (10 mg folic acid/L) diets. After 5 weeks, chronic consumption of the 36% ethanol diet significantly increased plasma alanine transaminase (ALT) (P < 0.05) and aspartate transaminase (AST) (P < 0.05), triglycerides (TG) (P < 0.05), Hcy (P < 0.001), and low density lipoprotein conjugated dienes (CD) (P < 0.05) but decreased total radical-trapping antioxidant potential (TRAP) (P < 0.001). These changes were prevented partially by folic acid supplementation. The 12% ethanol diet had no apparent effect on most parameters. Plasma Hcy concentration was well correlated with plasma ALT (r = 0.612(**)), AST (r = 0.652(*)), CD (r = 0.495(*)), and TRAP (r = -0.486(*)). The results indicate that moderately elevated Hcy is associated with increased oxidative stress and liver injury in alcohol-fed rats, and suggests that folic acid supplementation appears to attenuate hepatic toxicity induced by chronic ethanol consumption possibly by decreasing oxidative stress.
Full-text Article · Dec 2011 · Nutrition research and practice
[Show abstract][Hide abstract]ABSTRACT: High consumption of fruits and vegetables has been suggested to provide some protection to smokers who are exposed to an increased risk of numerous cancers and other degenerative diseases. Carrot is the most important source of dietary β-carotene. Therefore, the objective of this study was to investigate whether carrot juice supplementation to smokers can protect against lymphocyte DNA damage and to compare the effect of supplementation of capsules containing purified β-carotene or a placebo (simple lactose). The study was conducted in a randomized and placebo-controlled design. After a depletion period of 14 days, 48 smokers were supplemented with either carrot juice (n = 18), purified β-carotene (n = 16) or placebo (n = 14). Each group was supplemented for 8 weeks with approximately 20.49 mg of β-carotene/day and 1.2 mg of vitamin C/day, as carrot juice (300 ml/day) or purified β-carotene (20.49 mg of β-carotene, 1 capsule/day). Lymphocyte DNA damage was determined using the COMET assay under alkaline conditions and damage was quantified by measuring tail moment (TM), tail length (TL), and% DNA in the tail. Lymphocyte DNA damage was significantly decreased in the carrot juice group in all three measurements. The group that received purified β-carotene also showed a significant decrease in lymphocyte DNA damage in all three measurements. However, no significant changes in DNA damage was observed for the placebo group except TM (P = 0.016). Erythrocyte antioxidant enzyme was not significantly changed after supplementation. Similarly plasma lipid profiles were not different after carrot juice, β-carotene and placebo supplementation. These results suggest that while the placebo group failed to show any protective effect, carrot juice containing beta-carotene or purified β-carotene itself had great antioxidative potential in preventing damage to lymphocyte DNA in smokers.
Full-text Article · Dec 2011 · Nutrition research and practice
[Show abstract][Hide abstract]ABSTRACT: Oxidative stress leads to the induction of cellular oxidative damage, which may cause adverse modifications of DNA, proteins, and lipids. The production of reactive species during oxidative stress contributes to the pathogenesis of many diseases. Antioxidant defenses can neutralize reactive oxygen species and protect against oxidative damage. The aim of this study was to assess the antioxidant status and the degree of DNA damage in Korean young adults using glutathione s-transferase (GST) polymorphisms. The GSTM1 and GSTT1 genotypes were characterized in 245 healthy young adults by smoking status, and their oxidative DNA damage in lymphocytes and antioxidant status were assessed by GST genotype. General characteristics were investigated by simple questionnaire. From the blood of the subjects, GST genotypes; degree of DNA damage in lymphocytes; the erythrocyte activities of superoxide dismutase, catalase, and glutathione peroxidase; plasma concentrations of total peroxyl radical-trapping potential (TRAP), vitamin C, α- and γ-tocopherol, α- and β-carotene and cryptoxanthin, as well as plasma lipid profiles, conjugated diene (CD), GOT, and GPT were analyzed. Of the 245 subjects studied, 23.2% were GSTM1 wild genotypes and 33.4% were GSTT1 wild genotype. No difference in erythrocyte activities of superoxide dismutase, catalase, or glutathione peroxidase, and the plasma TRAP level, CD, GOT, and GPT levels were observed between smokers and non-smokers categorized by GSTM1 or GSTT1 genotype. Plasma levels of α- and γ-tocopherol increased significantly in smokers with the GSTT1 wild genotype (p < 0.05); however, plasma level of α-carotene decreased significantly in non-smokers with the GSTM1 wild genotype (p < 0.05). DNA damage assessed by the Comet assay was significantly higher in non-smokers with the GSTM1 null genotype; whereas DNA damage was significantly lower in non-smokers with the GSTT1 null genotype. Total cholesterol and LDL cholesterol levels were significantly higher in non-smokers with the GSTT1 null genotype than those with the GSTT1 wild genotype (p < 0.05). In conclusion, the GSTM1 null genotype or the GSTT1 wild genotype in non-smokers aggravated their antioxidant status through DNA damage of lymphocytes; however, the GSTT1 wild type in non-smokers had normal plasma total cholesterol and LDL-cholesterol levels. This finding confirms that GST polymorphisms could be an important determinant of antioxidant status and plasma lipid profiles in non-smoking young adults. Further study is necessary to clarify the antioxidant status and/or lipid profiles of smokers with the GST polymorphism and to conduct a study with significantly more subjects.
Article · Feb 2011 · The Korean Journal of Nutrition
[Show abstract][Hide abstract]ABSTRACT: This study was performed to develop a children's dietary life safety index required by the Special Act on Safety Management of Children's Dietary Life enacted in 2009. An analytical hierarchy process was used to obtain initial weights of dietary life safety evaluation indicators. The Delphi method was applied to develop the weights along with 98 food and nutrition professionals. Three representative policy indicators, nine strategy indicators, 11 main evaluation indicators, and 20 detailed evaluation indicators were selected for the children's dietary life safety assessment. Three policy indicators and nine strategy indicators were the following: children's food safety indicator (support level of children' safety, safety management level of children's favorite foods, and safety management level of institutional food service), children's nutrition safety indicator (management level of missing meals and obesity, nutrition management level of children's favorite foods, and nutrition management level of institutional food service), and children's perception and practice level indicator ("Dietary Life Law" perception level, perception, and practice level for dietary life safety management, perception, and practice level for nutrition management). Weights of 40%, 40%, and 20% were given for the three representative policy indicators. The relative importance of nine strategic indicators, which were determined by the Delphi method is as follows: For children's food safety, support level of children's safety, safety management level of children's favorite foods, and safety management level of institutional food service were given weights of 12%, 9%, and 19%, respectively. For children's nutrition safety, the missing meals and obesity management level, nutrition management level of children's favorite foods, and the nutrition management level of institutional food service were given weights of 13%, 11%, and 16%, respectively. The "Dietary Life Law" perception level, perception and practice level of dietary life safety management, and perception and practice level of nutrition management were given weights of 4%, 7%, and 9%, respectively.
Full-text Article · Feb 2011 · The Korean Journal of Nutrition