Effects Of Antioxidant Vitamin Supplementation Research Articles

Effects of antioxidant vitamin supplementation on sports performance, endurance and strength performance: a systematic review and meta-analysis

Effects of antioxidant vitamin supplementation on sports performance, endurance and strength performance: a systematic review and meta-analysis

Effect of Antioxidants on oxidative damage, and hematological and psychological parameters in cement-exposed workers

Some studies suggest that exposure to cement dust can cause oxidative stress, and have adverse effects on liver function, and hematological and psychological parameters. This study aimed to assess the effect of antioxidant vitamin supplementation on indices of oxidative stress, biochemical indicators, and psychological factors among cement plant workers. A total of 80 subjects (workers and non-exposed office employees) were divided into two groups. The intervention group that took vitamin E (400 IU)+ C (500 mg) and the control group that took placebo, for 60 days. The levels of malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD) and catalase (CAT) were measured in plasma, and hematological parameters were also recorded before and after the intervention. A significant decrease in the mean level of MDA, SOD and CAT, alkaline phosphatase (ALP), alanine transaminase (ALT) and aspartate transaminase (AST) were detected. On the other hand, a significant increase in the level of TAC was observed in the workers, after the intervention. Depression and anxiety also decreased significantly after the intervention. Vitamin E and C were probably effective in reducing oxidative stress and improving mental health and liver function especially among the workers.

Ram semen deterioration by short-term exposure to high altitude is prevented by improvement of antioxidant status

Ovine reproduction efficiency in herds at high altitude (ha) is lower than that at low altitude (la). In ewes, ha effects are due to hypoxia and oxidative stress. Our aim was to establish the effect of antioxidant vitamin supplementation on semen traits and antioxidant status of rams exposed to short or long time ha. A total of 32 rams native to la (~500 m) were used, 16 were kept at la and the other 16 were brought to ha (~3600 m), where they were placed in the same flock as the ha native rams (n=16). Half of the animals in each group were supplemented daily with vitamins C 600 mg and E 450 IU per os, during the entire experimental period, starting the 4th day after animal’s arrival at ha (day 0). At days 0, 30 and 60 of treatment, blood and semen samples were collected for evaluation of antioxidant status and semen standard characteristics. Data were compared within each experimental time by analysis of variance using a general linear model. Elevated concentrations of oxidative stress biomarkers were present in blood from animals maintained at ha. Ejaculates from ha exposed rams showed decreased sperm concentration, progressive motility and viability, in addition to decreased antioxidant status in seminal fluid. A total of 30 days of oral supplementation with vitamins C and E prevented some ha negative effects on semen characteristics, mainly in recently ha exposed rams. It is concluded that exposure of rams to ha negatively affects semen quality, where oxidative stress plays a predominant role. These effects are mainly prevented by oral supplementation of vitamins C and E, which constitutes a simple and cheap alternative to improve semen quality of rams when they are moved to ha.

The effects of antioxidant vitamin supplementation on expiratory flow rates at rest and during exercise.

Previous studies suggest that pulmonary function is associated with fruit and vegetable consumption and plasma concentrations of antioxidant vitamins. Also, expiratory flow limitation (EFL) has been reported to limit ventilation during exercise in healthy individuals. We hypothesized antioxidant vitamin supplementation (AVS) would increase resting expiratory flow rates in healthy subjects and reduce EFL during exercise. Ten healthy, nonsmoking subjects (5 M/5 W), consuming <5 servings of fruit and vegetables per day, participated in a randomized, single-blinded crossover design study with subjects receiving a placebo (PLA) or AVS [vitamins C (500 mg), E (400 IU), beta-carotene (15,000 IU), zinc (7.5 mg), selenium (50 mg), copper (1 mg), and manganese (2.5 mg)] for 4 weeks. After a minimum 4-week washout period, subjects received the alternate supplementation. Pulmonary function tests and total antioxidant status (TAS) from plasma were measured pre- and post-supplement period. Subjects completed a pre- and post-supplement treadmill test for 20 min at 70% [Formula: see text] followed by increasing workload until exhaustion. AVS increased (p < 0.05) TAS by ~21% and resting expiratory flow rates (FEF25-75, FEF50) by ~9%. Following AVS, %EFL was significantly reduced by ~15% at minute 15, 20, and end-exercise with no change (p > 0.05) in end-expiratory lung volumes. Breathing frequency and ratings of perceived exertion and dyspnea were also lower (p < 0.05) at min 20 of exercise. No changes (p > 0.05) were evident at rest or during exercise with PLA. These results suggest that AVS can increase TAS, improve resting expiratory flow rates and reduce EFL during exercise in healthy subjects who are not meeting fruit and vegetable recommendations.

Effect of antioxidant vitamin supplementation on endothelial function in type 2 diabetes mellitus: a systematic review and meta‐analysis of randomized controlled trials

Controversy exists among trials assessing whether prolonged antioxidant vitamin supplementation improves endothelial function in type 2 diabetes mellitus (T2DM) subjects. The aim of this study was to systematically review and quantify the effect of antioxidant vitamin supplementation on endothelial function in T2DM subjects. MEDLINE, Cochrane, Scopus and Web of Science were searched up to February 2013 for randomized controlled trials assessing the effect of antioxidant vitamin E and/or C supplementation on endothelial function in T2DM subjects. Ten randomized controlled trials comparing antioxidant vitamin-supplemented and control groups (overall n = 296) met the inclusion criteria. Post-intervention standardized mean difference (SMD) in endothelial function did not reach statistical significance between groups (0.35; 95% confidence interval = -0.17, 0.88; P = 0.18). In subgroup analysis, post-intervention endothelial function was significantly improved by antioxidant vitamin supplementation in T2DM subgroups with body mass index (BMI) ≤ 29.45 kg m(-2) (SMD = 1.02; P < 0.05), but not in T2DM subgroups with BMI > 29.45 kg m(-2) (SMD = -0.07; P = 0.70). In meta-regression, an inverse association was found between BMI and post-intervention SMD in endothelial function (B = -0.024, P = 0.02). Prolonged antioxidant vitamin E and/or C supplementation could be effective to improve endothelial function in non-obese T2DM subjects.

Effect of antioxidant vitamin supplementation on cardiovascular outcomes: a meta-analysis of randomized controlled trials.

BackgroundAntioxidant vitamin (vitamin E, beta-carotene, and vitamin C) are widely used for preventing major cardiovascular outcomes. However, the effect of antioxidant vitamin on cardiovascular events remains unclear.Methodology and Principal FindingsWe searched PubMed, EmBase, the Cochrane Central Register of Controlled Trials, and the proceedings of major conferences for relevant literature. Eligible studies were randomized controlled trials that reported on the effects of antioxidant vitamin on cardiovascular outcomes as compared to placebo. Outcomes analyzed were major cardiovascular events, myocardial infarction, stroke, cardiac death, total death, and any possible adverse events. We used the I2 statistic to measure heterogeneity between trials and calculated risk estimates for cardiovascular outcomes with random-effect meta-analysis. Independent extraction was performed by two reviewers and consensus was reached. Of 293 identified studies, we included 15 trials reporting data on 188209 participants. These studies reported 12749 major cardiovascular events, 6699 myocardial infarction, 3749 strokes, 14122 total death, and 5980 cardiac deaths. Overall, antioxidant vitamin supplementation as compared to placebo had no effect on major cardiovascular events (RR, 1.00; 95%CI, 0.96–1.03), myocardial infarction (RR, 0.98; 95%CI, 0.92–1.04), stroke (RR, 0.99; 95%CI, 0.93–1.05), total death (RR, 1.03; 95%CI, 0.98–1.07), cardiac death (RR, 1.02; 95%CI, 0.97–1.07), revascularization (RR, 1.00; 95%CI, 0.95–1.05), total CHD (RR, 0.96; 95%CI, 0.87–1.05), angina (RR, 0.98; 95%CI, 0.90–1.07), and congestive heart failure (RR, 1.07; 95%CI, 0.96 to 1.19).Conclusion/SignificanceAntioxidant vitamin supplementation has no effect on the incidence of major cardiovascular events, myocardial infarction, stroke, total death, and cardiac death.

Prevenção do estresse oxidativo na síndrome de isquemia e reperfusão renal em ratos com suplementação nutricional com antioxidantes

OBJETIVO: Verificar o potencial efeito protetor de suplementação com vitaminas antioxidantes em um modelo de síndrome de isquemia-reperfusão renal em ratos. MÉTODOS: Foram utilizados 29 ratos Wistar, divididos em três grupos: Grupo I e II (n=10 cada), submetidos a indução do estresse oxidativo pela aplicação de 60 minutos de isquemia renal, seguidos de 10 minutos de reperfusão; adicionalmente, os animais do Grupo II foram pré-tratados por doze dias com vitaminas antioxidantes (vitamina C 11,43mg/kg e vitamina E 28,57mg/kg) antes da submissão à isquemia; Grupo III (n=9), correspondendo aos animais Sham, que foram manipulados de forma equivalente aos outros grupos, porém sem indução do estresse oxidativo e sem suplementação antioxidante. Findo isso, as amostras de sangue e os rins foram colhidos para avaliação dos níveis do malondialdeído, do ácido úrico e da capacidade antioxidante total. RESULTADOS: Para o malondialdeído e ácido úrico do Grupo I foi observado um aumento estatisticamente significante (p&lt;0,01) em relação ao Grupo III, o qual não apresentou diferença em relação ao Grupo II. Para os níveis de capacidade antioxidante total, foi encontrada uma diminuição nos animais do Grupo I em relação aos Grupos II e III (p&lt;0,01). CONCLUSÃO: Esses dados confirmam não apenas a efetiva participação do estresse oxidativo neste modelo de síndrome de isquemia e reperfusão renal em ratos, como também que o uso de vitaminas antioxidantes, associadas à dieta, pode proteger os animais das alterações oxidativas.

Does Antioxidant Vitamin Supplementation Protect against Muscle Damage?

The high forces undergone during repetitive eccentric, or lengthening, contractions place skeletal muscle under considerable stress, in particular if unaccustomed. Although muscle is highly adaptive, the responses to stress may not be optimally regulated by the body. Reactive oxygen species (ROS) are one component of the stress response that may contribute to muscle damage after eccentric exercise. Antioxidants may in turn scavenge ROS, thereby preventing or attenuating muscle damage. The antioxidant vitamins C (ascorbic acid) and E (tocopherol) are among the most commonly used sport supplements, and are often taken in large doses by athletes and other sportspersons because of their potential protective effect against muscle damage. This review assesses studies that have investigated the effects of these two antioxidants, alone or in combination, on muscle damage and oxidative stress. Studies have used a variety of supplementation strategies, with variations in dosage, timing and duration of supplementation. Although there is some evidence to show that both antioxidants can reduce indices of oxidative stress, there is little evidence to support a role for vitamin C and/or vitamin E in protecting against muscle damage. Indeed, antioxidant supplementation may actually interfere with the cellular signalling functions of ROS, thereby adversely affecting muscle performance. Furthermore, recent studies have cast doubt on the benign effects of long-term, high-dosage antioxidant supplementation. High doses of vitamin E, in particular, may increase all-cause mortality. Although some equivocation remains in the extant literature regarding the beneficial effects of antioxidant vitamin supplementation on muscle damage, there is little evidence to support such a role. Since the potential for long-term harm does exist, the casual use of high doses of antioxidants by athletes and others should perhaps be curtailed.

Antioxidant Status of Subjects with Essential Hypertension in a Nigerian Population

Objectives: To investigate the antioxidant status of normotensive and hypertensive Nigerians and the effect of antioxidant vitamin supplementation on sustained blood pressures (systolic blood pressure ≥160mm Hg and diastolic blood pressure ≥100mm Hg) in hypertensive subjects. Methods: A total of 130 subjects aged 25–68 years were recruited for the study. Of the hypertensive subjects investigated, 30 were newly diagnosed and were not on any antihypertensive drug, but had systolic blood pressure ≥160mm Hg and diastolic blood pressure ≥100mm Hg, and 50 were already on drug therapy. Fifty were Nigerian normotensive controls with blood pressure ≤120/90mm Hg. Results: Measurement of catalase and superoxide dismutase activities and plasma concentrations of ascorbic acid (vitamin C) and tocopherol (vitamin E) as an assessment of total antioxidant status indicated that hypertensive subjects had a significantly lower antioxidant status than normotensive subjects (p < 0.05). Antioxidant vitamin supplementation for 2 weeks reduced systolic/diastolic blood pressures of the newly diagnosed hypertensive subjects from 171/104 to 164/95mm Hg, while the hypertensive subjects already on antihypertensive drugs had their blood pressures reduced significantly to 136/85mm Hg. Conclusions: The beneficial effects of blood pressure lowering in hypertensive subjects by antihypertensive drug therapy is improved and is further enhanced when their antioxidant status is adequately high.

The effects of antioxidant vitamin supplementation on resistance exercise induced lipid peroxidation in trained and untrained participants

BackgroundThe theoretical benefits of using antioxidant vitamin supplements to quench oxygen free radicals appear large. High intensity aerobic-type exercise produces oxygen free radicals that can cause damage to lipid membranes (lipid peroxidation) that may lead to many problems such as the inactivation of cell membrane enzymes, the progression of degenerative diseases (cardiovascular disease and cancer) and lessening of the effectiveness of the immune system. The major function of vitamin E is to work as a chain-breaking antioxidant in a fat soluble environment. Little research has examined lipid peroxidation associated with high intensity resistance exercise or possible protective effects of antioxidant supplementation or the effects of training state.ResultsThere were no significant group (trained vs untrained) or treatment (vitamin E vs placebo) effects found between the 4 groups assessed. There was only one significant difference found and that was in the main effect for time (F = 22.41, p < 0.01).ConclusionsThe Resistance Exercise Test caused a significant increase in malondialdehyde in all 4 groups at 6 hours post exercise. There was no evidence that vitamin E supplementation was effective in reducing oxidative damage in comparison to the placebo group. As well, there was no difference between the trained and untrained groups with respect to their impact on lipid peroxidation measures.

Antioxidant vitamin supplementation in Crohn’s disease decreases oxidative stress: a randomized controlled trial

Objective We showed previously that patients with Crohn’s disease (CD) had increased oxidative stress and lower antioxidant vitamins compared with healthy controls. This is despite inactive or mildly active disease and maintenance therapy. The aim of this study was to evaluate in these patients the effects of antioxidant vitamin supplementation on oxidative stress. Methods This is a randomized controlled trial where stable but oxidatively stressed CD subjects (n = 57) were supplemented with vitamins E (800 IU) and C (1000 mg) or their placebo for 4 wk. Oxidative stress measured by breath pentane and ethane output, plasma lipid peroxides, and F2-isoprostane was assessed at baseline and at 4 wk. Disease activity was also monitored by measuring CD activity index and plasma orosomucoid. Results During supplementation, plasma vitamin C and α-tocopherol increased and all indices of oxidative stress decreased significantly. Disease activity remained stable. Conclusions In this population, vitamin E and C supplementation resulted in a significant reduction in oxidative stress. This suggests that patients with inactive or mildly active CD can be oxidatively stressed and have increased requirement in antioxidant vitamins.

Effects of antioxidant vitamin supplementation in patients with HIV infection

Effects of antioxidant vitamin supplementation in patients with HIV infection

The effect of antioxidant vitamin supplementation on traditional cardiovascular risk factors

The effect of antioxidant vitamin supplementation on traditional cardiovascular risk factors