The effect of antioxidant vitamins E and C on cognitive performance of the elderly with mild cognitive impairment in Isfahan, Iran: a double-blind, randomized, placebo-controlled trial.

PURPOSE: This study was carried out to investigate the effect of vitamins E and C on cognitive performance among the elderly in Iran. METHODS: About 256 elderly with mild cognitive impairment, aged 60-75 years, received 300 mg of vitamin E plus 400 mg of vitamin C or placebo daily just for 1 year. BACKGROUND: Demographic characteristics, anthropometric variables food consumption, cognitive function by Mini-Mental State Examination (MMSE), and some of the oxidative stress biomarkers were examined. RESULTS: Antioxidant supplementation reduced malondialdehyde level (P < 0.001) and raised total antioxidant capacity (P < 0.001) and glutathione (P < 0.01). The serum 8-hydroxydeoxyguanosine remained unchanged (P < 0.4). After adjusting for the covariates effects, MMSE scores following 6- (25.88 ± 0.17) and 12-month antioxidant supplementation (26.8 ± 0.17) did not differ from control group (25.86 ± 0.18 and 26.59 ± 0.18, respectively). CONCLUSION: Despite significant improvement in most of the oxidative stress biomarkers, antioxidants' supplementation was not observed to enhance cognitive performance. A large number of kinetic and/or dynamic factors could be suspected.

Barriers for progress in salt reduction in the general population. An international study.

Salt reduction is important for reducing hypertension and the risk of cardiovascular events, nevertheless worldwide salt intakes are above recommendations. Consequently strategies to reduce intake are required, however these require an understanding of salt intake behaviours to be effective. As limited information is available on this, an international study was conducted to derive knowledge on salt intake and associated behaviours in the general population. An online cohort was recruited consisting of a representative sample from Germany, Austria, United States of America, Hungary, India, China, South Africa, and Brazil (n=6987; aged 18-65 years; age and gender stratified). Participants completed a comprehensive web-based questionnaire on salt intake and associated behaviours. While salt reduction was seen to be healthy and important, over one third of participants were not interested in salt reduction and the majority were unaware of recommendations. Salt intake was largely underestimated and people were unaware of the main dietary sources of salt. Participants saw themselves as mainly responsible for their salt intake, but also acknowledged the roles of others. Additionally, they wanted to learn more about why salt was bad for health and what the main sources in the diet were. As such, strategies to reduce salt intake must raise interest in engaging in salt reduction through improving understanding of intake levels and dietary sources of salt. Moreover, while some aspects of salt reduction can be globally implemented, local tailoring is required to match level of interest in salt reduction. These findings provide unique insights into issues surrounding salt reduction and should be used to develop effective salt reduction strategies and/or policies.

Efficacy of flour fortification with folic acid in women of childbearing age in Iran.

BACKGROUND: Flour fortification with folic acid is one of the main strategies for improving folate status in women of childbearing age. No interventional trial on the efficacy of folic acid fortification has been conducted so far in Iran. OBJECTIVES: To study the effects of flour fortification with folic acid on any reduction in neural tube defects (NTDs) and folate status of women of childbearing age. METHODS: In a longitudinal hospital-based study, 13,361 postpartum women were studied after admission for childbirth before and after fortification. In addition, two cross-sectional surveys were conducted before (2006) and after flour fortification (2008). The cluster sampling method was used and 580 women, 15-49 years old, were studied as a representative sample of Golestan province in the north of Iran. Fasting blood samples were collected to measure serum vitamin B(12), folate and plasma homocysteine. Sociodemographic data, health characteristics and dietary intake were determined. RESULTS: The mean daily intakes of folate from natural food before and after flour fortification were 198.3 and 200.8 µg/day, respectively. The total folate intake increased significantly from 198.3 to 413.7 µg/day after fortification (p < 0.001). Folate intake increased by an average of 226 µg/day from fortified bread. The mean serum folate level increased from 13.6 to 18.1 nmol/l; folate deficiency decreased from 14.3 to 2.3% (p < 0.001). The incidence rate of NTDs declined by 31% (p < 0.01) in the post-fortification period (2.19 per 1,000 births; December 2007 to December 2008) compared to the pre-fortification period (3.16 per 1,000 births; September 2006 to July 2007). CONCLUSIONS: Implementation of mandatory flour fortification with folic acid can lead to a significant increase in serum folate and a significant decrease in NTDs.

Plasma beta-carotene is not a suitable biomarker of fruit and vegetable intake in german subjects with a long-term high consumption of fruits and vegetables.

BACKGROUND/OBJECTIVE: beta-Carotene is often used as a marker for the amount of fruit and vegetables consumed, but little is known about plasma beta-carotene concentrations in subjects whose habitual (long-term) diets are characterized by different amounts of foods of plant origin. We compared dietary beta-carotene intake and plasma concentrations in women on habitual diets differing in the consumed amounts of foods of plant origin. METHODS: A comparison of dietary beta-carotene intakes and plasma beta-carotene concentrations in women adhering to an average Western diet (n = 172), wholesome nutrition (following preventive recommendations) (n = 238) or a raw food diet (n = 104). RESULTS: Dietary beta-carotene intake was 5.5, 9.3, 14.7 mg/day for women adhering to an average Western diet, wholesome nutrition and raw food diet, respectively (p < 0.001). Corresponding multivariate adjusted plasma beta-carotene concentrations were 1.07, 1.65, and 1.16 micromol/l, respectively (p < 0.001). Comparable dietary beta-carotene intake resulted in lower multivariate adjusted plasma beta-carotene in women adhering to a raw food diet and average Western diet compared to those on wholesome nutrition (p < 0.001 for all intake groups up to 20 mg/day). The amount of fruit and vegetable intake did not predict plasma beta-carotene levels in women consuming a raw food diet. CONCLUSIONS: Plasma beta-carotene concentrations differed among the diet groups, with highest plasma levels in women adhering to wholesome nutrition. Plasma beta-carotene concentrations may not reflect beta-carotene intake and the amount of fruit and vegetables consumed.

Dietary fat intake--a global perspective.

BACKGROUND/AIM: The objective of this review was to collect data on the dietary intake of total fat and saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA), especially linoleic (LA), alpha-linolenic (ALA), eicosapentaenoic and docosahexaenoic fatty acids, in adults from various countries and to compare them with current recommendations for fat intake. METHODS: Weighted mean intake data were collected from national dietary surveys, large cross-sectional studies and/or studies with focus on health and nutrition. Thereof, only studies with diet recalls, weighing records or food frequency questionnaires were considered. RESULTS: Data from 28 countries were included, representing Africa (3), America (4), Asia (5), Australia/New Zealand (2) and Europe (14). Total fat intake ranged from 11.1 (China, Guangxi Bai Ku Yao and Han populations) to 50.7 (rural dwellers in Nigeria) percentages of total energy (%E). SFA intake varied from 3.1 (China, Guangxi Bai Ku Yao and Han populations) to 25.4%E (rural dwellers in Nigeria). Mean MUFA and PUFA intake ranged from 3.5 (China, Guangxi Bai Ku Yao and Han populations) to 22.3 (Greece), and 3.3 (India) to 11.3%E (Taiwan), respectively. The mean intake of LA and ALA was between 2.7 (India) and 7.2 (Austria), and 0.4 (France) and 1.0%E (Finland). CONCLUSION: With regard to recommendations for fat intake, no general advice for improvements can be given worldwide. Due to different dietary patterns, only regionally specific recommendations can be made about what would be necessary to modify and improve fat quantity and quality of the diet.

Use of fiber instead of laxative treatment in a geriatric hospital to improve the wellbeing of seniors.

INTRODUCTION: Constipation is a common problem in the elderly population, especially in geriatric wards. Laxatives are the most preferred solution but current studies link constipation and laxative use to weight-loss and malnutrition in nursing homes. Dietary fibers also affect stool weight and transit time. So, oat-bran effectiveness in reducing the need for bowel medication and weight-loss for geriatric care patients was examined in a geriatric hospital. AIM: To determine whether the addition of oat-bran to common oral diet can reduce the use of laxatives and improve the wellbeing and bodyweight of the inhabitants of a long-term-care facility. METHODS: The study was designed as a controlled blind intervention trial among 30 frail inhabitants of a geriatric hospital aged 57-100 years with laxative use. Including criteria were: oral food intake and laxatives as therapy and excluding criteria were: parenteral and enteral feeding, surgeries in the gastro- intestinal tract, drugs that shorten or lengthen the passage through the gut, risk of aspiration, swallowing troubles. An intervention and a control group were formed. 15 of them received 7-8 g oat-bran/d for 12 weeks (fiber group) mixed up in the daily common diet of the ward and 15 served as control (control group). DATA COLLECTION: Bodyweight was taken at baseline, after 6 weeks and at the end of the supplementation. Data on laxative use, stool frequency and the eating habits of the elderly were recorded. RESULTS: Laxatives were successfully discontinued by 59% (p < 0.001) in the fiber-group; in the control-group there was an increase of 8% (p=0.218). Bodyweight remained constant in the fiber-group and decreased in the control-group (p=0.002). The oat-fiber supplementation in the introduced form was well tolerated. CONCLUSIONS: Use of oat-fiber allowed discontinuation of laxatives by 59% while improving body-weight and wellbeing of the seniors. Fiber supplementation is a safe and convenient alternative to laxatives in a geriatric hospital.

Development and validation of a food frequency index using nutritional biomarkers in a sample of middle-aged and older adults.

BACKGROUND: An index of diet quality, which examines different aspects of a diet concurrently, may facilitate the identification of poor dietary habits in population sub-groups. The objectives of the present study were to develop a food frequency index (FFI) and to test its associations with nutritional biomarkers and nutrient intake. METHODS: The study comprised a cross-sectional survey among 444 adults aged 55 years and older in Vienna, Austria, and a sub-sample of 226 subjects who provided fasting blood specimen. Data from a qualitative 28-item food-frequency questionnaire were used to develop the FFI. RESULTS: FFI scores were positively correlated with plasma concentrations of beta-carotene (r = 0.26), beta-cryptoxanthin (r = 0.31), zeaxanthin (r = 0.19), lutein (r = 0.21), phylloquinone (r = 0.19), 25-hydroxyvitamin D (r = 0.20), and serum high-density lipoprotein (HDL)-cholesterol (r = 0.24) and were negatively correlated with the ratio of total : HDL-cholesterol (r = -0.23). Sub-groups with higher FFI scores had, on average, lower intakes of total fat, saturated fat, and dietary cholesterol and higher intakes of total carbohydrates, dietary fibre, and most of the examined micronutrients. CONCLUSION: The FFI as a measure of diet quality has the ability to discern population sub-groups, with reasonable validity, into low- or high-risk dietary habits.

Personal, social and environmental predictors of daily fruit and vegetable intake in 11-year-old children in nine European countries.

OBJECTIVE: To investigate potential personal, social and physical environmental predictors of daily fruit intake and daily vegetable intake in 11-year-old boys and girls in nine European countries. SUBJECTS: The total sample size was 13 305 (90.4% participation rate). RESULTS: Overall, 43.2% of the children reported to eat fruit every day, 46.1% reported to eat vegetables every day. Daily fruit intake and daily vegetable intake was mainly associated with knowledge of the national recommendations, positive self-efficacy, positive liking and preference, parental modeling and demand and bringing fruit to school (odds ratio between 1.40 and 2.42, P<0.02). These factors were associated fairly consistently with daily fruit intake across all nine European countries, implying that a rather uniform intervention strategy to promote fruit can be used across Europe. For vegetables, the pattern was, however, less consistent. Differences between countries in cooking and preparing vegetables might be responsible for this larger diversity. CONCLUSIONS: This study showed that especially a combination of personal and social factors is related to daily fruit and vegetable intake in schoolchildren. This shows that a comprehensive multilevel intervention strategy based upon a series of individual and social correlates will be most promising in the promotion of daily fruit and vegetable intake in children.

Assessment of the nutritional situation of elderly nursing home residents in Vienna.

BACKGROUND: In Austria, reliable information about the nutritional situation of institutionalized, frail elderly is lacking. METHODS: MNA (Mini Nutritional Assessment) and NuRAS (Nutritional Risk Assessment Scale), tools specifically developed to evaluate the nutritional status of the elderly, were used for the assessment of the general nutritional and health status of the residents. Individual intake of energy and nutrients was measured by using the weighed food intake method during 7 consecutive weekdays. RESULTS: According to MNA results (n = 245), 13.9% had a satisfactory nutritional status, 48.3% were assessed as 'at risk of malnutrition', and 37.8% as being 'malnourished'. There is evidence that the number of assessed nutritional risk factors has an impact on the nutritional status. Further, there is a link between the assessed nutritional status and the individual nutrient intake of the residents. CONCLUSION: There is evidence for nutritional problems in frail, institutionalized elderly nursing home residents. The MNA seems to be a reliable tool to identify individuals at risk for malnutrition. Strategies for effective nutritional intervention should be implemented in long-term care facilities for the elderly in order to prevent and treat malnutrition and to ensure high-quality care.

Folate, vitamin B12 and homocysteine status in women of childbearing age: baseline data of folic acid wheat flour fortification in Iran.

BACKGROUND: Folic acid fortification implemented mandatorily in many countries has been associated with significant increase in blood folate concentrations and reduction in the prevalence of neural tube defects. However, there are controversial findings on the probability of vitamin B(12) deficiency being masked in the population after folic acid fortification. Baseline data on folate and vitamin B(12) status are necessary before mandatory flour fortification is implemented. OBJECTIVES: To assess dietary intake of folate and vitamin B(12) and to determine blood concentrations of folate, vitamin B(12) and homocysteine in women of childbearing age as baseline data regarding folic acid fortification in Iran. METHODS: A descriptive cross-sectional survey was performed with 579 healthy women as a representative sample of the Golestan province. Fasting blood samples were taken and dietary (24-hour recall), health and sociodemographic data were collected with an interview. Serum concentrations of folate and vitamin B(12) were measured with radioimmunoassay, and plasma homocysteine concentrations were assessed by high-performance liquid chromatography with fluorescence detection. RESULTS: Mean serum concentrations of folate and vitamin B(12) were 13.6 nmol/l (95% CI 12.8-14.4) and 194.4 pmol/l (95% CI 183.8-205.0), respectively. Inadequate serum folate levels were present in 14.3% of the women and 22.7% had serum vitamin B(12) levels below normal. Mean plasma homocysteine concentration was 12.6 micromol/l (95% CI 12.1-13.2) and hyperhomocysteinemia was observed in 38.3% of the women. Mean daily intake of folate and vitamin B(12) was 198.3 microg (95% CI 185.4-211.3) and 2.6 microg (95% CI 1.9-3.2), respectively. Folate intake from food was positively correlated with serum folate concentrations (r = 0.084, p < 0.05) and inversely correlated with plasma homocysteine concentrations (r = -0.115, p < 0.01). CONCLUSIONS: An insufficient vitamin B(12) as well as folate status is present in Iranian women of childbearing age. The final evaluation will be carried out 18 months after flour fortification and the results will be compared with baseline data obtained from the present study in order to show the efficacy and safety of folic acid fortification in Iran.

Outcomes of the Nutri-Senex project: a co-ordination action funded by the European Commission.

This project's primary aim is to contribute to the improvement of the quality of life of the elderly. The state of the art in age-related research and technology, to highlight the most promising areas for development, has been documented in an extensive literature report. A research database has been established to map current research activities within the European research area. Through several expert group meetings with representatives from universities, research institutions, organizations concerned with the care of the elderly, and industry, suitable technologies and policies that can improve the diet of the elderly have been identified. A legislation survey relating to aspects of nutrition of the elderly has been carried out. A set of guidelines and recommendations of best practice for use in the health and care industry have been developed. The project's results are disseminated through an enhanced website, technology transfer workshops and a staff training program. Good communication between the partners has been promoted and permanent research links have been forged. The main outputs will lead to better co-ordinated European research: less duplication of effort, more rapid commercialization, increased awareness of the problems faced by the elderly, improved guidelines and recommendations for health care professionals and policymakers.

Eating at restaurants, at work or at home. Is there a difference? A study among adults of 11 European countries in the context of the HECTOR* project.

BACKGROUND/OBJECTIVES: To compare macronutrient intakes out of home-by location-to those at home and to investigate differences in total daily intakes between individuals consuming more than half of their daily energy out of home and those eating only at home. SUBJECTS/METHODS: Data collected through 24-h recalls or diaries among 23 766 European adults. Participants were grouped as 'non-substantial', 'intermediate' and 'very substantial out-of-home' eaters based on energy intake out of home. Mean macronutrient intakes were estimated at home and out of home (overall, at restaurants, at work). Study/cohort-specific mean differences in total intakes between the 'very substantial out-of-home' and the 'at-home' eaters were estimated through linear regression and pooled estimates were derived. RESULTS: At restaurants, men consumed 29% of their energy as fat, 15% as protein, 45% as carbohydrates and 11% as alcohol. Among women, fat contributed 33% of energy intake at restaurants, protein 16%, carbohydrates 45% and alcohol 6%. When eating at work, both sexes reported 30% of energy from fat and 55% from carbohydrates. Intakes at home were higher in fat and lower in carbohydrates and alcohol. Total daily intakes of the 'very substantial out-of-home' eaters were generally similar to those of individuals eating only at home, apart from lower carbohydrate and higher alcohol intakes among individuals eating at restaurants. CONCLUSIONS: In a large population of adults from 11 European countries, eating at work was generally similar to eating at home. Alcoholic drinks were the primary contributors of higher daily energy intakes among individuals eating substantially at restaurants.

B-vitamin status and concentrations of homocysteine in Austrian omnivores, vegetarians and vegans.

BACKGROUND: A vegetarian diet is considered to promote health and longevity and reduce the risk of cardiovascular diseases and cancer. However, a vegetarian diet may be deficient in some nutrients. Exclusion of animal products in vegetarian diets may affect the status of certain B-vitamins, and further cause the rise of plasma homocysteine concentration. OBJECTIVE: The nutritional status of various B-vitamins (B(1), B(2), B(6), B(12), folic acid) and the concentration of homocysteine in blood plasma of omnivores (n = 40), vegetarians (n = 36) and vegans (n = 42) in Austria was evaluated. METHODS: The evaluation was done using the functional parameters erythrocyte transketolase (ETK), glutathione reductase (EGR) and glutamic oxaloacetic transaminase (EGOT) activation coefficients. Enzyme activity was measured photometrically. The quantity of vitamins B(1), B(2) and B(6) in urine and the concentrations of vitamin B(6) and homocysteine in plasma were determined by HPLC methods with fluorescence detection. Plasma concentration of vitamin B(12) and folic acid were measured with radioimmunoassay. RESULTS: Most of the subjects showed a satisfying vitamin B(1) status. Vegans presented a significantly lower mean plasma vitamin B(12) concentration than omnivores and vegetarians and deficiency in 2.4% of the volunteers but the highest mean value of plasma folate among the investigated groups. A deficient status of folate was found in 18% of omnivores and in approximately 10% of vegans and vegetarians. The status of riboflavin is considered to be deficient in about 10% of omnivores and vegetarians and in over 30% of vegans. According to the activation coefficient of GOT, approximately one third of all subjects showed vitamin B(6) deficiency. Elevated homocysteine concentration in plasma was observed in 66% of the vegans and about 45-50% of the omnivores and vegetarians. Vegan subjects had significantly higher mean plasma homocysteine levels than omnivores. CONCLUSION: Thiamin and folate need not be a problem in a well-planned vegan diet. Vitamins B(12) and B(2) may need attention in the strict vegan diet, especially regarding elevated homocysteine levels in plasma. Pyridoxine status appeared to be independent of the diet.

Selected quality parameters of salmon and meat when fried with or without added fat.

AIM: To determine whether pan-frying (pork, beef and salmon) without oil or with different fats (olive oil, corn oil or a partially hydrogenated plant oil) or steaming (only salmon) have effects on the total fat content, the fatty acid pattern, lipid peroxidation, tocopherols and in particular for salmon on vitamin D(3) and astaxanthin. MATERIAL AND METHODS: Pork, beef patties and salmon were pan-fried (6 min each), beef fillet was pan-fried (5 min) with an additional braising period of 90 minutes and salmon was steamed for 12 minutes. Each pan-frying treatment was done with the above mentioned fats and without fat. Total fat was determined gravimetrically, the fatty acid pattern with GC, the tocopherols, astaxanthin and vitamin D(3) by using HPLC. RESULTS: The effects on the fat quality and quantity in the final products were related to the pan-frying fat used, however, the power of the outcome was depending on the surface to volume ratio. The highest increase in total fat was observed for pork, followed by the beef patties and the braised beef. The same has been assessed for the fatty acid pattern. Tocopherols changed according to the oil used, in particular gamma-tocopherol significantly increased for each preparation after the use of corn oil. Only in pork an increase in lipid oxidation of the oil preparations has been observed. Vitamin D(3) in salmon significantly decreased after heat treatment, however a 150 g salmon portion would provide between 13.9 and 14.7 mug Vitamin D(3) which is around five times more than the average daily intake. CONCLUSION: Pan-frying without fat can be recommended for the daily use, since the total fat intake is too high in developed countries and one main task of nutritional recommendations is to reduce the total fat intake. When pan-fried with fat, the choice of the fat is of high importance since it directly influences the quality and the flavour of the final product. In order to increase the fat quality from nutritional point of view only oils of plant or vegetable origin should be used in households. Pan-fried salmon is a good source of Vitamin D(3).

Lipid oxidation of beef fillets during braising with different cooking oils.

Effects of braising without oil and with different cooking oils (olive oil, corn oil and partially hydrogenated plants oil) on the susceptibility to lipid oxidation in beef fillets (psoas major) were evaluated. The beef fillets were pan-fried without oil or with the respective oils for five min, followed by 90 min steam cooking (braising). Lipid oxidation status of the samples and the cooking residues was evaluated by peroxide value (PV), acid value (AV), p-Anisidine value (p-AnV), as well as the alteration of the tocopherol content. Total lipids and the individual fatty acid pattern were analyzed in order to determine the impact of the frying medium as well as the cooking procedures on the fat of the braised samples. The decrease in PV simultaneous with the significant increase in p-AnV indicated the progression of lipid oxidation. Tocopherol and fatty acid contents of all the investigated samples exhibited modifications mainly due to the influence of the frying medium and braising process. Although there was a significant change in lipid oxidation parameters, there is no risk in consuming such braised meat.

Executive summary and conclusions from the European Hydration Institute Expert Conference on human hydration, health, and performance.

On April 7-8, 2014, the European Hydration Institute hosted a small group of experts at Castle Combe Manor House, United Kingdom, to discuss a range of issues related to human hydration, health, and performance. The meeting included 18 recognized experts who brought a wealth of experience and knowledge to the topics under review. Eight selected topics were addressed, with the key issues being briefly presented before an in-depth discussion. Presented here is the executive summary and conclusions from this meeting.

Beneficial effects of protease inhibitors on body composition and energy expenditure: a comparison between HIV-infected and AIDS patients.

OBJECTIVES: (i) To investigate whether protease inhibitor (PI) (nelfinavir)-containing highly active antiretroviral therapy (HAART) affects body composition differently in HIV-infected and AIDS patients without wasting syndrome. (ii) To delineate the changes in resting energy expenditure (REE) under PI therapy, and to determine whether sustained reductions in HIV RNA would decrease REE. DESIGN: Prospective longitudinal cohort study with individually matched healthy controls. SETTING: Tertiary care centre at a University Hospital. METHODS: HIV-seropositive (n = 20) and AIDS patients (n = 17) with a plasma viral load of at least 10000 copies/ml and 37 healthy volunteers were enrolled. All participants were weight stable, free of acute opportunistic infections, and naive to PI therapy. Patients underwent testing of bioelectrical impedance analysis (BIA), indirect calorimetry and food intake, shortly before the initiation of HAART and 24 weeks thereafter. RESULTS: Both patient groups gained weight, body mass index (BMI), and fat-free mass (FFM) (P < 0.05 versus baseline), whereas only AIDS patients gained fat mass. Increases were more pronounced in the AIDS group. REE was elevated compared with corresponding controls at baseline, and decreased similarly in HIV and in AIDS patients during PI therapy (P < 0.05). The reduction in the viral burden preceded the decrease in REE by several weeks. CONCLUSION: Body composition and metabolic parameters improved during PI therapy in HIV-infected and AIDS patients without wasting. Although an early reduction in viral load as a result of HAART does not seem to influence REE directly, sustained viral load suppression may promote a decrease in energy expenditure.

Exercise and oxidative stress: significance of antioxidants with reference to inflammatory, muscular, and systemic stress.

Many studies have demonstrated that intense muscular work generates considerable amounts of reactive oxygen species (ROS). In order to prevent oxidative stress, the body contains a large number of nonenzymatic and enzymatic antioxidants that either prevent ROS formation or scavenge radical species. Oxidative stress can lead to damage or destruction of cellular macromolecules such as lipids, proteins, and nucleic acids. Therefore, oxidative stress has been associated with decreased physical performance, muscular fatigue, muscle damage, and overtraining. It has been hypothesized that the body's physiological amount of antioxidants is not sufficient to prevent exercise-induced oxidative stress and that additional antioxidants are needed to reduce oxidative stress, muscular damage, or overshooting inflammation. However, some but not all investigations have demonstrated oxidative stress following physical exercise, and also, findings concerning the role of antioxidants in reducing oxidative stress are equivocal. In addition, a clear association between the amount of exercise-induced muscular, metabolic, hormonal, or inflammatory stress and levels of antioxidant vitamins could not be established consistently. Therefore, although the theoretical background may be sound, there is no scientific evidence to recommend increased quantities of antioxidants to physically active people exceeding the amount provided by a healthy, balanced nutrition.

Status of lipidsoluble antioxidants and TRAP in patients with Crohn's disease and healthy controls.

OBJECTIVE: To assess the status of lipidsoluble antioxidants (carotenoids, tocopherols, ubiquinone), retinol and their correlation with TRAP (total radical-trapping antioxidant potential) in patients with Crohn's disease. DESIGN: Prospective case-control study. SETTING: Clinic of Internal Medicine IV/Department of Gastroenterology and Hepatology, University of Vienna Medical School. SUBJECTS/METHODS: Plasma antioxidant concentrations were determined in patients with Crohn's disease (n = 24) to evaluate the antioxidant capacity compared to healthy controls (n = 33). Additionally, plasma TRAP (total radical-trapping antioxidant potential) was measured in 13 patients and 22 controls. RESULTS: All investigated carotenoids (alpha-carotene, beta-carotene and cryptoxanthin) were significantly decreased in patients with Crohn's disease (10.2 +/- 9.3, 16.2 +/- 12.4 and 7.8 +/- 5.5 microg/dl) compared to controls (13.3 +/- 5.1, 34.7 +/- 18.8 and 48.5 +/- 38.4 microg/dl respectively), whereas gamma-tocopherol and ubiquinone were significantly elevated in patients (0.14 +/- 0.07 microg/dl and 82.3 +/- 41.5 microg/dl, controls: 0.09 +/- 0.04 microg/dl and 60.8 +/- 30.0 microg/dl, respectively). Retinol and alpha-tocopherol did not significantly differ from controls. The total radical-trapping antioxidant potential (TRAP) was significantly lower in patients (1.11 +/- 0.28 micromol/l) compared to controls (1.34 +/- 0.26 micromol/l). Antioxidants were neither related to duration or severity of disease nor to disease activity. CONCLUSIONS: In patients with Crohn's disease several plasma antioxidant parameters are altered and the total radical-trapping antioxidant potential is decreased.