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1.
OBJECTIVE: C-reactive protein (CRP) may directly affect the progression of atherosclerosis, and therefore, may be a target for reducing disease risk. The objective was to determine whether antioxidant supplementation reduces plasma CRP in active and passive smokers. DESIGN: Randomized, double-blind, placebo-controlled, parallel group trial with 2 months exposure to study supplements. SETTING: Berkeley and Oakland, California. SUBJECTS: Healthy adult men and women, consuming <4 daily servings of fruits and vegetables, and who were actively or passively exposed to cigarette smoke. Analysis was limited to participants with detectable baseline CRP concentrations and no evidence of inflammation associated with acute illness at baseline or follow-up as reflected in CRP elevations (> or =10.0 mg/L). A total of 1393 individuals were screened, 216 randomized, 203 completed the study, and 160 were included in the analysis. INTERVENTIONS: Participants were randomized to receive a placebo or vitamin C (515 mg/day) or antioxidant mixture (per day: 515 mg vitamin C, 371 mg alpha-tocopherol, 171 mg gamma-tocopherol, 252 mg mixed tocotrienols, and 95 mg alpha-lipoic acid). Measures of Outcome: Change in plasma CRP concentration. RESULTS: Vitamin C supplementation yielded a 24.0% reduction (95% confidence interval, -38.9% to -5.5%, p = 0.036 compared to control) in plasma CRP, whereas the antioxidant mixture and placebo produced a nonsignificant 4.7% reduction (-23.9% to 19.3%) and 4.3% increase (-15.1% to 28.2%), respectively. Results were adjusted for baseline body mass index and CRP concentrations. CONCLUSIONS: Plasma CRP itself may serve as a potential target for reducing the risk of atherosclerosis, and antioxidants, including vitamin C, should be investigated further to confirm their CRP-lowering and anti-inflammatory effects.  相似文献   

2.
Antioxidant vitamin status and carotid atherosclerosis in the elderly   总被引:2,自引:0,他引:2  
BACKGROUND: The oxidative modification of LDL is thought to play a crucial role in the initiation of atherosclerosis. Antioxidant vitamins can protect LDL from oxidation, and high intakes or blood concentrations of these vitamins have been linked with a reduced risk of cardiovascular disease. Few data are available on the importance of antioxidant vitamins in earlier stages of atherogenesis. OBJECTIVE: We investigated the cross-sectional relation between antioxidant vitamin status and carotid atherosclerosis in a group of elderly persons. DESIGN: The study sample comprised 468 men and women aged 66-75 y living in Sheffield, United Kingdom. Duplex ultrasonography was used to measure intima-media thickness and the degree of stenosis in the extracranial carotid arteries. Antioxidant vitamin status was assessed by measuring fasting plasma concentrations of vitamin C, vitamin E, and beta-carotene. RESULTS: In the men, after adjustment for age and cardiovascular disease risk factors, a 20% higher plasma vitamin C concentration was associated with a 0.004-mm smaller intima-media thickness; a 20% higher beta-carotene concentration was associated with a 0.005-mm smaller intima-media thickness. Compared with men with high blood concentrations of beta-carotene or cholesterol-adjusted vitamin E, those with low blood concentrations of these vitamins were 2.5 times as likely to have carotid stenosis of >30%. We found no significant trends between plasma concentrations of antioxidant vitamins and either measure of carotid atherosclerosis in the women. CONCLUSION: A high antioxidant vitamin status may help to prevent the initiation and progression of early atherosclerotic lesions in men.  相似文献   

3.
OBJECTIVE: Short-term cigarette smoke (CS) exposure leads to acute lung inflammation through its influence over oxidants/antioxidants imbalance. Antioxidant vitamins such as ascorbic acid and alpha-tocopherol interact with oxidizing radicals. It is not clear if antioxidant supplementation can reduce inflammatory lung responses. Thus our aim was to analyze the effects of vitamin supplementation on the lungs of mice exposed to six cigarettes per day with histologic, cytological, and biochemical methods. METHODS: C57BL/6 mice were exposed to ambient air (control) or CS from 3, 6, 9, 12, or 15 cigarettes daily for up to 5 d. Mice alveolar macrophages and polymorphonuclear cells were counted in the bronchoalveolar lavage. Groups of CS animals received 50 mg/kg of ascorbic acid daily and/or 50 mg/kg of alpha-tocopherol daily as an oral supplementation (CS+C, CS+E, CS+C+E, respectively) 12 h before CS exposure. Thiobarbituric acid-reactive substances were detected and western blot to nuclear factor-kappaB were performed in lung extracts; metalloprotease-12 and tumor necrosis factor-alpha positive alveolar macrophages were quantified in the lungs processed for immunohistochemistry of the animals exposed to the smoke from six cigarettes daily for 5 d. RESULTS: The number of alveolar macrophages and polymorphonuclear cells in bronchoalveolar lavage (cells x 10(3)/mL) in mice exposed to CS were increased and CS with vitamin supplementation groups presented bronchoalveolar lavage cells similar to those of control. Thiobarbituric acid-reactive substances values were reduced in vitamin supplementation groups when compared with CS and the lower value was found in the CS+C+E group. Metalloprotease-12 and tumor necrosis factor-alpha were more evident in CS as much as nuclear factor-kappaB activation when compared with control and vitamin supplementation groups. CONCLUSION: Our results showed that CS induced acute lung inflammation. The inflammatory process after cigarette exposures was reduced by ascorbic acid, alpha-tocopherol, or more efficiently by both vitamin supplementations.  相似文献   

4.
Cognitive function in elderly people is influenced by vitamin E status   总被引:3,自引:0,他引:3  
The aim of this study was to examine associations between vitamin E status and cognitive performance in elderly people. The study subjects were a group of 34 men and 86 women, aged 65-91 y, who were free of significant cognitive impairment. Dietary intake was monitored using a "weighed food record" for 5 consecutive days including a Sunday. Serum levels of alpha-tocopherol and cholesterol were determined by HPLC and colorimetric methods, respectively. The cognitive capacity of subjects was tested using the Pfeiffer's Mental Status Questionnaire (PMSQ). Subjects with vitamin E intakes lower than 50% of those recommended had higher PMSQ scores, demonstrating a greater number of errors in comparison to participants with a greater intake of the vitamin (0.91 +/- 1.22 vs. 0.47 +/- 0.60, respectively, P < 0.05). Subjects who made no errors in the PMSQ test had significantly higher serum alpha-tocopherol concentrations (19.7 +/- 8.6 micromol/L in men and 20.0 +/- 8.4 micromol/L in women) and alpha-tocopherol/cholesterol ratios (3.5 +/- 2.0 micromol/mmol in men 2.9 +/- 1.4 micromol/mmol in women) compared with those who made errors (alpha-tocopherol 15.1 +/- 5.6 micromol/L in men and 14.9 +/- 6.1 micromol/L in women; alpha-tocopherol/cholesterol ratio 2.4 +/- 0.8 and 2.3 +/- 1.3 micromol/mmol in men and women, respectively). This study shows there to be a relationship between vitamin E status and cognitive function, and that vitamin E status could be improved in this population of elderly individuals.  相似文献   

5.
OBJECTIVE: To study the lipoprotein distribution of supplemented coenzyme Q10 (CoQ10), vitamin E, and polyunsaturated fatty acids (PUFA). DESIGN: Balanced three-period crossover study. SETTING: University research unit. SUBJECTS: Eighteen apparently healthy free-living non-smoking volunteers (nine women, nine men), mean age 26 +/- 3 y, recruited among the university students; no dropouts. INTERVENTIONS: Three supplementation periods of 10 days: 100 mg/day CoQ10, 350 mg/day D-alpha-tocopherol, and 2 g/day concentrated fish oil. Fasting venous blood samples were collected twice before the first period and then after each period. Plasma and isolated lipoproteins were analysed for cholesterol, triacylglycerol, alpha- and gamma-tocopherol, CoQ10, and fatty acid composition. RESULTS: Significant (P < 0.05) increase in CoQ10 and alpha-tocopherol occurred in all lipoprotein classes after supplementation. CoQ10 was primarily incorporated into low-density lipoprotein (LDL). alpha-tocopherol and fish oil n-3 PUFAs had similar patterns. They were equally distributed between LDL and high-density lipoprotein (HDL), with a smaller part in VLDL. The total sum of PUFA was unchanged following all supplementations, but fish oil increased the amount of n-3 fatty acids at the expense of n-6 fatty acids. CONCLUSION: Lipoprotein distribution of CoQ10 is markedly different from that of alpha-tocopherol, suggesting that they may be metabolised by distinct routes. alpha-Tocopherol is distributed similarly to n-3 fatty acids, thus providing protection on location for the oxidatively labile PUFAs.  相似文献   

6.
OBJECTIVE: To examine the association between plasma concentrations of C-reactive protein (CRP) and the intake of vitamins and trace elements from supplements possibly related to inflammation such as vitamin C, vitamin E, carotenoids, selenium and zinc. DESIGN: Cross-sectional study using data from the Monitoring of Trends and Determinants in Cardiovascular Disease/Cooperative Health Research in the Region of Augsburg (MONICA/KORA) Survey 1994/95. SETTING: Region of Augsburg, Southern Germany. SUBJECTS: Population-based sample of 2045 women and 2172 men, aged 25-74 years. RESULTS: Intake of dietary supplements containing vitamins and trace elements was associated with lower CRP levels in women. Especially vitamin E in combination with other vitamins like vitamin C, vitamin B(1), B(2), B(6), B(12), niacin, folic acid, pantothenic acid and selenium, was significantly associated with lower CRP levels. Odds ratios for elevated CRP levels (>3.0 mg/l) after multivariable adjustment were 0.57 (95% confidence interval (CI): 0.37, 0.89) for the intake of vitamin E and 0.57 (95% CI: 0.35, 0.91) for the intake of multivitamins, defined as taking three or more different vitamins. These associations were not seen in men. Intake of vitamin C, carotenoids or zinc was not significantly associated with levels of CRP in both men and women. CONCLUSIONS: Our data indicate that the intake of certain vitamins and trace elements from supplements is associated with lower CRP concentrations in women. Thus, intake of these micronutrients could influence the inflammatory process underlying the pathogenesis of atherosclerosis. Specific dose response relationships and the best combinations of vitamins and trace elements have to be determined in further studies.  相似文献   

7.
8.
Inflammation and endothelial activation are associated with an increased risk of CVD and epidemiological evidence suggests an association between levels of markers of inflammation or endothelial activation and the intake of fruit. Also, vitamin E, a fat-soluble antioxidant, has anti-inflammatory properties. We performed a randomised 2 x 2 factorial, crossover trial to determine the effect of orange and blackcurrant juice (500 ml/d) and vitamin E (15 mg RRR-alpha-tocopherol/d) supplementation on markers of inflammation and endothelial activation in forty-eight patients with peripheral arterial disease. Patients were randomly allocated to two dietary supplements from the four possible combinations of juice and vitamin E: juice+vitamin E; juice+placebo; reference beverage (sugar drink)+vitamin E; and reference beverage+placebo. The supplementations were given for 28 d, separated by a 4-week wash-out period. Analysis of main effects showed that juice decreased C-reactive protein (CRP) by 11% and fibrinogen by 3% while the reference drink increased CRP by 13% and fibrinogen by 2% (P<0.008 and P<0.002, respectively). No significant differences were measured for IL-6 and the endothelial activation markers von Willebrand factor, tissue-plasminogen activator and plasmin activator inhibitor-1. Vitamin E supplementation had no significant effects on the various markers. We observed no significant interaction between juice and vitamin E. In this study, orange and blackcurrant juice reduced markers of inflammation, but not markers of endothelial activation, in patients with peripheral arterial disease, relative to sugar drinks.  相似文献   

9.
The effect of supplementary Vitamin E on the vitamin content of lipoproteins in young men and women. Inappropriate vitamin and trace element supplementation may facilitate the development of atherosclerosis. It is known that Vitamin E protects lipids from oxidative stress, while clinical signs of atherosclerosis appear later in women compared to men. AIMS: (1) The increase of vitamin E in plasma and plasma lipoproteins after 4 weeks of supplementation vitamin E was investigated, (2) furthermore it was tested whether a proportion shift occurs in alpha-tocopherol content of lipoproteins, (3) and checked for gender-related differences in plasma and plasma lipoprotein vitamin E levels before, during and after treatment, (4) plasma CRP levels as a marker of lipid peroxidation were also followed. METHODS: 5-5 young healthy men and women took part in the study, receiving 700 IU/day Vitamin E for one month. Each subject was studied before and at the end of treatment, and also one month after treatment. HDL and LDL-VLDL containing lipoproteins were separated. Vitamin E and hsCRP levels were measured (by HPLC and an immunoturbidimetric method, respectively). RESULTS: Vitamin E treatment induced in both genders an approximately threefold increase in vitamin E concentration in HDL-cholesterol (8.1 +/- 1.7 micromol/l vs. 22.5 +/- 7.5 micromol/l, p < 0.001), and a twofold increase in LDL-VLDL-cholesterol (22.0 +/- 3.7 micromol/l vs. 49.0 +/- 9.0 micromol/l, p < 0.001). Plasma and HDL vitamin E levels were higher in women than in men at the onset of treatment (6.8 +/- 0.96 micromol/l vs. 9.5 +/- 1.10 micromol/l), but during the treatment these gender-related differences disappeared. When plasma vitamin E concentration were considered 100% and the changes of the vitamin E concentrations of lipoproteins were calculated, it was found that supplementation with vitamin E in men increased the vitamin E concentration of LDL-VLDL cholesterol to a higher extent compared to women (LDL-VLDL % in men: 59.8 +/- 7.43%, in women: 49.3 +/- 7.41%, p < 0.05). All the observed changes regressed one month after cessation of supplementation. The level of hsCRP decreased during vitamin E treatment (1.07 +/- 0.9 mg/l vs. 0.2 +/- 0.14 mg/l, p < 0.001), and remained suppressed after the cessation of treatment (0.37 +/- 0.4, p < 0.01). CONCLUSIONS: These results support the hypothesis that women at young age are better protected against lipid-peroxidation as compared to men because of higher HDL vitamin E concentrations. Vitamin E supplementation in men eliminates this concentration difference between genders, and also increases LDL-VLDL vitamin E. In both genders high concentration of vitamin E in lipoproteins was associated with low hsCRP concentration.  相似文献   

10.
OBJECTIVE: To assess relationships between energy, nutrient and food intakes, alcohol consumption, smoking status and body mass index (BMI), and serum concentrations of beta-carotene, alpha-tocopherol, vitamin C, selenium and zinc. METHODS: Data on health status, alcohol consumption, smoking habits, anthropometric data and biochemical measurements were obtained in 1821 women aged 35-60 y and 1307 men aged 45-60 y, participant to the SU.VI.MAX Study. Data on dietary intake were available on a subsample who reported six 24-h dietary records during the first 18 months of the study. RESULTS: Women had higher baseline serum beta-carotene and vitamin C concentrations and lower concentration for serum vitamin E, zinc and selenium than men. In women, younger age was associated with lowered mean concentration of serum beta-carotene, vitamin E and selenium. In men, only differences were observed for serum zinc, which was lower in older men. Current smokers of both sexes had significantly lower concentrations of serum beta-carotene, vitamin C and selenium, and, only in women, of vitamin E, than nonsmokers. Alcohol consumers had lower concentrations of serum beta-carotene and higher selenium concentrations. Serum beta-carotene and vitamin C concentrations were lower in obese subjects. There were positive associations of dietary beta-carotene, vitamin C and E with their serum concentrations. Age, nutrient and alcohol intakes, serum cholesterol, BMI and smoking status explained 15.2% of the variance of serum beta-carotene in men and 13.9% in women, and 10.8 and 10.0% for serum vitamin C, and 26.3 and 28.6% for serum vitamin E, respectively. CONCLUSION: Serum antioxidant nutrient concentrations are primarily influenced by sex, age, obesity, tobacco smoking, alcohol consumption and especially dietary intake of those antioxidant nutrients.  相似文献   

11.
OBJECTIVE: We investigated the effects of vitamin E and C supplementation on the fatty acid composition of mononuclear cells and on the clinical observations in patients who had chronic hepatitis C and received interferon-alpha-2b (IFN-alpha-2b) and ribavirin combination therapy. METHODS: Patients were randomly allocated to receive daily 500 mg of vitamin E and 750 mg of vitamin C (vitamin group, n = 14) or no supplement (non-vitamin group, n = 16) in addition to IFN-alpha-2b and ribavirin therapy. The fatty acid composition of mononuclear cell phospholipids was analyzed before and at 2, 4, and 8 wk after treatment. RESULTS: After vitamin supplementation, plasma and red blood cell alpha-tocopherol and plasma ascorbic acid levels increased in the vitamin group. Serum levels of alanine aminotransferase decreased significantly after 2 wk of treatment in both groups. At the start of treatment, a lower level of eicosapentaenoic acid (EPA) and a higher level of the molar ratio of arachidonic acid to EPA in mononuclear cells were observed in the present patients compared with healthy volunteers, and a significant correlation between the molar ratio and serum alanine aminotransferase level was found. The EPA level of mononuclear cells was maintained in the vitamin group during treatment, whereas a significant decrease was observed in the non-vitamin group at 4 and 8 wk after treatment. CONCLUSIONS: Antioxidant vitamin supplementation during IFN-alpha-2b and ribavirin therapy prevented a decrease in EPA of mononuclear cell phospholipids. If a further decrease in the ratio of arachidonic acid to EPA can be achieved by using oral EPA supplementation, the efficacy of IFN-alpha-2b and ribavirin therapy may be improved.  相似文献   

12.
BACKGROUND: Little is known about age- and disease-related changes in prooxidant and antioxidant systems in patients with cystic fibrosis (CF). OBJECTIVE: We investigated changes in antioxidant concentrations and oxidative stress in plasma, buccal mucosal cells (BMCs), and breath condensate in patients with CF in relation to age and disease progression. DESIGN: We recruited 22 patients with CF as well as 35 healthy control subjects and conducted a cross-sectional study by dividing the participants into 4 age groups (<6 y, 6-11 y, 12-17 y, > or =18 y). We collected fasting blood samples, BMCs, and breath condensate. Carotenoids, alpha-tocopherol, vitamin C, protein carbonyls, thiobarbituric acid-reactive substances, and F(2)alpha-isoprostane were assessed. RESULTS: In patients with CF, plasma vitamin C concentrations, plasma and BMC alpha-tocopherol concentrations, and forced expiratory volume in 1 s (percentage predicted) decreased significantly with age. Plasma beta-carotene, beta-cryptoxanthin, and total lycopene were significantly lower in patients than in control subjects in all age groups. Furthermore, alpha-tocopherol and vitamin C plasma concentrations as well as alpha-tocopherol concentrations in BMCs were significantly lower in CF patients > or =18 y old, whereas all indicators of oxidative stress assessed were significantly higher than those same indicators in control subjects. CONCLUSIONS: Adult patients with CF in particular showed distinct vitamin deficits and elevated indicators of oxidative stress in plasma, BMCs, and breath condensate along with a progression of clinical status. We suggest that early in life dietary habits should be improved and that innovative supplementation strategies should be applied to optimize the antioxidant status of patients with CF.  相似文献   

13.
OBJECTIVE: The "Marathon des Sables" (MDS) is a competition known to induce oxidative stress. Antioxidant vitamins prevent exercise-induced oxidative damages. The purpose of this study was to evaluate daily intake and plasma level of the main antioxidant vitamins (alpha-tocopherol, vitamin C, beta-carotene and retinol) in 19 male athletes who participated in this competition. METHODS: Data collected before the beginning of the competition included daily dietary intake using a 7-day food record and plasma biochemical measurements (alpha-tocopherol, vitamin C, beta-carotene and retinol). RESULTS: First, total energy intake was obviously lower than the energetic intake usually observed in well-trained endurance athletes. Second, antioxidant vitamins intake was also insufficient. Indeed, the intake was lower than the French Dietary Reference Intakes (DRI) for this population in 18 subjects for vitamin E and 6 subjects for vitamin C, beta-carotene and Retinol Equivalent. As a significant relationship was found between total energy intake and the intake of vitamin E (r = 0.73; p < 0.001) and vitamin C (r = 0.78; p < 0.001), the low total energy intake contributed partially to the insufficient antioxidant vitamins intake. The dietary questionnaire analysis also revealed a low intake of vegetable oils, fruits and vegetables. However, plasma concentrations of these antioxidant vitamins were similar to the literature data observed in athletes. CONCLUSION: This study evidenced obvious insufficient energy intake in ultra endurance athletes associated with a low antioxidant vitamin intake.  相似文献   

14.
Few studies provide correlations between different indicators of the dietary intakes of older (>or= 65 y) black and white adults. This study compared the usual intakes of vitamin E, vitamin C, and selected carotenoids estimated by a modified Harvard food frequency questionnaire (FFQ) to those estimated by multiple 24-h recalls, and to blood concentrations of components in a randomly selected sample of participants in the Chicago Health and Aging Project (CHAP). Subjects (n = 59) were interviewed to complete multiple 24-h recalls over a year's time, then completed an FFQ and subsequently provided a fasting blood specimen within 2 mo. Dietary estimates were energy-adjusted separately for men and women. Significant (P < 0.05) correlations between total (diet and supplement) FFQ estimates and serum measures of vitamin E and vitamin C were as follows: 0.49 and 0.39 for blacks, and 0.42 and 0.29 for whites, respectively. The highest correlations between serum and FFQ indicators were for dietary beta-cryptoxanthin (0.46), total alpha-tocopherol (0.46) and total beta-carotene (0.44) among whites; among blacks, the highest correlations were for dietary alpha-carotene (0.81), total alpha-tocopherol (0.53) and total beta-cryptoxanthin (0.50); all were significant (P < 0.05). Further adjustment for age, gender, BMI, and educational level minimally altered these coefficients. These findings indicate that the modified Harvard FFQ provides reasonable estimates of serum levels of vitamin E, vitamin C and beta-cryptoxanthin among CHAP participants.  相似文献   

15.
Vitamin E is an efficient antioxidant and a modulator of the immune system. Although racial differences in both baseline vitamin E level and immunologic subsets are known, no reliable data exist for the Asian population. Furthermore, the extent of the effect of alpha-tocopherol in protecting lymphocyte cells against oxidative stress and its association with cell-mediated immunity have not been elucidated. This study was undertaken to investigate the immunologic and antioxidant effects of vitamin E in healthy ethnic Chinese men and women. Volunteers < 35 y old (n = 26) were supplemented with 233 mg/d dl-alpha-tocopherol for 28 d. The in vitro proliferative response to phytohemagglutinin (PHA) or lipopolysaccharide (LPS) of T-lymphocytes was determined in the study group before and after vitamin E supplementation. Cell-mediated immunity subsets and hydrogen peroxide production in T-lymphocytes were investigated by flow cytometry. The oxidant-antioxidant balance in plasma and urine was studied by spectrophotometric and gas chromatography-mass selective detection methods. The antioxidant properties of vitamin E were established (P: < 0.01) by the elevation of plasma vitamin E, together with depression in both plasma malondialdehyde and urinary DNA adduct 8-hydroxy-2'-deoxyguanosine after supplementation. Our data suggest a specific requirement for vitamin E in total-T and T-helper cell proliferation. We present the first evidence of the beneficial effects of supplemental vitamin E in healthy Chinese individuals on cell-mediated immunity and oxidative stress.  相似文献   

16.
We administered high-dose vitamin E to healthy adult male volunteers and assessed the safety of such supplementation. Fourteen volunteers received daily 1,200 IU of vitamin E (800 mg of D-alpha-tocopherol) for 28 d and eight controls were also enrolled. The volunteers treated with vitamin E showed no abnormalities during the study period. The alpha-tocopherol concentrations of plasma and platelets were markedly elevated by vitamin E treatment, but there were no significant differences in platelet aggregation, coagulation, and the clinical parameters between the two groups. In conclusion, a high dose of vitamin E for 28 d had no adverse effects in healthy men.  相似文献   

17.
Vitamin C supplementation has been suggested to reduce cardiovascular disease risk. However, no studies have examined the relationship between vitamin C status and vascular dysfunction in lean and obese individuals in the absence of supplementation. We examined whether vascular function is interrelated with vitamin C status and inflammation in healthy, college-aged lean and obese men with no history of dietary supplementation. A cross-sectional study was conducted during winter 2008 in lean and obese men aged 21±3 years (n=8/group). Brachial artery flow-mediated dilation (FMD) was measured to determine vascular endothelial function. Plasma antioxidants (vitamin C, vitamin E, and thiols), inflammatory proteins (C-reactive protein [CRP], myeloperoxidase [MPO], and cytokines), and cellular adhesion molecules were measured. Participants also completed 3-day food records on the days preceding their vascular testing. Group differences were evaluated by t tests, and correlation coefficients were determined by linear regression. FMD was 21% lower (P<0.05) in obese men. They also had 51% lower vitamin C intakes and 38% lower plasma vitamin C concentrations. Obese men had greater plasma concentrations of CRP, MPO, inflammatory cytokines, and cellular adhesion molecules. Participants' CRP and MPO were each inversely related (P<0.05) to FMD (r=−0.528 and −0.625) and plasma vitamin C (r=−0.646 and −0.701). These data suggest that low vitamin C status is associated with proinflammatory responses and impaired vascular function in lean and obese men. Additional study is warranted to determine whether improving dietary vitamin C intakes from food attenuate vascular dysfunction.  相似文献   

18.
The concentration of tocopherols in blood serum, liver and adipose tissue of growing pigs with different vitamin E supply was estimated gas-chromatographically. The animals were fed with a practical diet, supplemented with 0, 5, 15, 25 and 95 ppm dl-alpha-tocopheryl acetate (groups I-V). Based on a naturally vitamin E content of 7.4 and 8.6 mg per kg of the diet the control animals (group I) showed very low tocopherol concentrations of 0.5 mug per ml serum and about 1 mug per g tissue. No clinical vitamin E-deficiency symptoms were observed. The increasing alpha-tocopherol supplements raised the vitamin E contents in a proportional rate, and with high vitamin E supplies the highest quantities of tocopherols were stored in the adipose tissue. When the alpha-tocopherol content in the diet was raised by 1 mg, the concentration in the serum increased by 0.033 mug per ml, in the liver by 0.094 and in the adipose tissue by 0.129 mug per g, respectively (gamma = 0.99). This increase in the concentrations was strongly linear and can be interpreted by constant rates of absorption and retention of alpha-tocopherol in the present investigation. The growth of the pigs was no influenced by the different alpha-tocopherol supplements.  相似文献   

19.
OBJECTIVE: To examine alpha-tocopherol intake and food sources of alpha-tocopherol in the US population relative to current Dietary Reference Intakes for vitamin E. DESIGN: We analyzed food source and intake data from the 1994 to 1996 Continuing Survey of Food Intakes by Individuals (CSFII) with added values for alpha-tocopherol from the US Department of Agriculture National Nutrient Database for Standard Reference Release 15. SUBJECTS: Data from 5,056 men and 4,703 women aged 20 years and older were obtained from the 1994 to 1996 CSFII. STATISTICAL ANALYSES PERFORMED: The complex design and sampling weights of the CSFII survey were taken into account to calculate the mean alpha-tocopherol intake from diet, the SEM, and the percent of the Estimated Average Requirements (EARs) for alpha-tocopherol intake by age group and region. RESULTS: Only 8.0% of men and 2.4% of women in the United States met the new EARs for vitamin E intake from foods alone. Regionally, only 5.8% of men and 2.1% of women in the South met these EARs, relative to 9.0% and 2.6%, respectively, in the Northeast. Top contributors of alpha-tocopherol for men and women included ready-to-eat cereal, sweet baked products, white bread, beef, oils, and salad dressing. APPLICATIONS/CONCLUSIONS: The majority of men and women in the United States fail to meet the current recommendations for vitamin E intake. Many of the top contributors are not particularly high sources of alpha-tocopherol but are consumed frequently. Greater inclusion of sources such as nuts, seeds, and vitamin E-rich oils, could improve intake of alpha-tocopherol.  相似文献   

20.
BACKGROUND: Oxidative stress and inflammation are crucial in atherogenesis. alpha-Tocopherol is both an antioxidant and an antiinflammatory agent. OBJECTIVE: We evaluated the effect of RRR-alpha-tocopherol supplementation on carotid atherosclerosis in patients with stable coronary artery disease (CAD) on drug therapy. DESIGN: Randomized, controlled, double-blind trial compared RRR-alpha-tocopherol (1200 IU/d for 2 y) with placebo in 90 patients with CAD. Intimal medial thickness (IMT) of both carotid arteries was measured by high-resolution B-mode ultrasonography at 0, 1, 1.5, and 2 y. At 6-mo intervals, plasma alpha-tocopherol concentrations, C-reactive protein (CRP), LDL oxidation, monocyte function (superoxide anion release, cytokine release, and adhesion to endothelium), and urinary F(2)-isoprostanes were measured. RESULTS: alpha-Tocopherol concentrations were significantly higher in the alpha-tocopherol group but not in the placebo group. High-sensitivity CRP concentrations were significantly lowered with alpha-tocopherol supplementation than with placebo (32%; P < 0.001). alpha-Tocopherol supplementation significantly reduced urinary F(2)-isoprostanes (P < 0.001) and monocyte superoxide anion and tumor necrosis factor release compared with baseline and placebo (P < 0.001). No significant difference was observed in the mean change in total carotid IMT in the placebo and alpha-tocopherol groups. In addition, no significant difference in cardiovascular events was observed (P = 0.21). CONCLUSIONS: High-dose RRR-alpha-tocopherol supplementation in patients with CAD was safe and significantly reduced plasma biomarkers of oxidative stress and inflammation but had no significant effect on carotid IMT during 2 y.  相似文献   

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