Abstract:
BACKGROUND:Animal and physiological research as well as observational studies suggest that antioxidant supplements may improve survival. OBJECTIVES:To assess the effect of antioxidant supplements on mortality in primary or secondary prevention randomised clinical trials. SEARCH STRATEGY:We searched The Cochrane Library (Issue 3, 2005), MEDLINE (1966 to October 2005), EMBASE (1985 to October 2005), and the Science Citation Index Expanded (1945 to October 2005). We scanned bibliographies of relevant publications and wrote to pharmaceutical companies for additional trials. SELECTION CRITERIA:We included all primary and secondary prevention randomised clinical trials on antioxidant supplements (beta-carotene, vitamin A, vitamin C, vitamin E, and selenium) versus placebo or no intervention. Included participants were either healthy (primary prevention trials) or had any disease (secondary prevention trials). DATA COLLECTION AND ANALYSIS:Three authors extracted data. Trials with adequate randomisation, blinding, and follow-up were classified as having a low risk of bias. Random-effects and fixed-effect meta-analyses were performed. Random-effects meta-regression analyses were performed to assess sources of intertrial heterogeneity. MAIN RESULTS:Sixty-seven randomised trials with 232,550 participants were included. Forty-seven trials including 180,938 participants had low risk of bias. Twenty-one trials included 164,439 healthy participants. Forty-six trials included 68111 participants with various diseases (gastrointestinal, cardiovascular, neurological, ocular, dermatological, rheumatoid, renal, endocrinological, or unspecified). Overall, the antioxidant supplements had no significant effect on mortality in a random-effects meta-analysis (relative risk [RR] 1.02, 95% confidence interval [CI] 0.99 to 1.06), but significantly increased mortality in a fixed-effect model (RR 1.04, 95% CI 1.02 to 1.06). In meta-regression analysis, the risk of bias and type of antioxidant supplement were the only significant predictors of intertrial heterogeneity. In the trials with a low risk of bias, the antioxidant supplements significantly increased mortality (RR 1.05, 95% CI 1.02 to 1.08). When the different antioxidants were assessed separately, analyses including trials with a low risk of bias and excluding selenium trials found significantly increased mortality by vitamin A (RR 1.16, 95% CI 1.10 to 1.24), beta-carotene (RR 1.07, 95% CI 1.02 to 1.11), and vitamin E (RR 1.04, 95% CI 1.01 to 1.07), but no significant detrimental effect of vitamin C (RR 1.06, 95% CI 0.94 to 1.20). Low-bias risk trials on selenium found no significant effect on mortality (RR 0.91, 95% CI 0.76 to 1.09). AUTHORS' CONCLUSIONS:We found no evidence to support antioxidant supplements for primary or secondary prevention. Vitamin A, beta-carotene, and vitamin E may increase mortality. Future randomised trials could evaluate the potential effects of vitamin C and selenium for primary and secondary prevention. Such trials should be closely monitored for potential harmful effects. Antioxidant supplements need to be considered medicinal products and should undergo sufficient evaluation before marketing.
journal_name
Cochrane Database Syst Revjournal_title
The Cochrane database of systematic reviewsauthors
Bjelakovic G,Nikolova D,Gluud LL,Simonetti RG,Gluud Cdoi
10.1002/14651858.CD007176subject
Has Abstractpub_date
2008-04-16 00:00:00pages
CD007176issue
2issn
1469-493Xpub_type
杂志文章,meta分析,评审abstract:BACKGROUND:Clavicle fractures are common, accounting for 2.6% to 4% of all fractures. Eighty per cent of clavicle fractures are located in the middle third of the clavicle. Although treatment of these fractures is usually non-surgical, displaced clavicle fractures may be considered for surgical treatment because of the...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析
doi:10.1002/14651858.CD009363.pub3
更新日期:2019-01-22 00:00:00
abstract:BACKGROUND:Herbal medicines are being used as a treatment for viral diseases such as viral myocarditis and numerous clinical trials have been conducted to investigate their efficacy. Despite this wealth of evidence, the role of herbal medicines in the treatment of viral myocarditis is yet to be established. This is an ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD003711.pub4
更新日期:2012-11-14 00:00:00
abstract:BACKGROUND:Endometriosis is a common gynaecological condition that frequently presents with the symptom of pain. The precise pathogenesis (mode of development) of endometriosis is unclear but it is evident that endometriosis arises by the dissemination of endometrium to ectopic sites and the subsequent establishment of...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD000346
更新日期:2000-01-01 00:00:00
abstract:BACKGROUND:Calcineurin inhibitors used in kidney transplantation for immunosuppression have adverse effects that may contribute to nephrotoxicity and increased cardiovascular risk profile. Fish oils are rich in very long chain omega-3 fatty acids, which may reduce nephrotoxicity by improving endothelial function and re...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD005282.pub2
更新日期:2007-04-18 00:00:00
abstract:BACKGROUND:Respiratory syncytial virus infection causes acute lung infection in infants and young children worldwide, resulting in considerable morbidity and mortality. Children with cystic fibrosis are prone to recurrent lung inflammation, bacterial colonisation and subsequent chronic airway disease, putting them at r...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD007743.pub6
更新日期:2016-07-20 00:00:00
abstract:BACKGROUND:Malaria causes repeated illness in children living in endemic areas. Policies of giving antimalarial drugs at regular intervals (prophylaxis or intermittent treatment) are being considered for preschool children. OBJECTIVES:To evaluate chemoprophylaxis and intermittent treatment with antimalarial drugs to p...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD003756.pub2
更新日期:2005-10-19 00:00:00
abstract:BACKGROUND:Continuous Positive Airways Pressure (CPAP) is considered to be the cornerstone of therapy for obstructive sleep apnoea (OSA). However, compliance with this treatment is frequently poor, which may lead to ongoing symptoms of sleep disruption, daytime sleepiness and poor waking cognitive function. Mechanical ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD003531.pub3
更新日期:2009-10-07 00:00:00
abstract:BACKGROUND:Preterm infants have low plasma levels of erythropoietin (EPO), providing a rationale for the use of erythropoiesis-stimulating agents (ESAs) to prevent or treat anaemia and to provide neuro protection and protection against necrotising enterocolitis (NEC). Darbepoetin (Darbe) and EPO are currently available...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析
doi:10.1002/14651858.CD004863.pub6
更新日期:2020-02-11 00:00:00
abstract:BACKGROUND:An advance directive is a document specifying a person's preferences for treatment, should he or she lose capacity to make such decisions in the future. They have been used in end-of-life settings to direct care but should be well suited to the mental health setting. OBJECTIVES:To examine the effects of adv...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD005963.pub2
更新日期:2009-01-21 00:00:00
abstract:BACKGROUND:Surgery remains a mainstay of treatment for malignant tumours; however, surgical manipulation leads to a significant systemic release of tumour cells. Whether these cells lead to metastases is largely dependent on the balance between aggressiveness of the tumour cells and resilience of the body. Surgical str...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD008877.pub2
更新日期:2014-11-07 00:00:00
abstract:BACKGROUND:Osteomyelitis (both acute and chronic) is one of the most common infectious complications in people with sickle cell disease. There is no standardized approach to antibiotic therapy and treatment is likely to vary from country to country. Thus, there is a need to identify the efficacy and safety of different...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD007175.pub3
更新日期:2012-12-12 00:00:00
abstract:BACKGROUND:Guillain-Barré syndrome is a potentially serious, acute, paralysing, probably autoimmune disease caused by inflammation of the peripheral nerves. Recovery has been shown to be speeded by plasma exchange which replaces the patient's own plasma with a plasma substitute. Intravenous immunoglobulin purified from...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD002063
更新日期:2001-01-01 00:00:00
abstract:BACKGROUND:Mental health problems in children are common. Research suggests that parenting has an important role to play in helping children to become well adjusted adults, and that the first few months and years of a child's life are especially important in establishing patterns of emotional, cognitive and social func...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD003680
更新日期:2002-01-01 00:00:00
abstract:BACKGROUND:Narcolepsy is a disorder of the central nervous system, the main symptoms of which are excessive daytime sleepiness (EDS) and cataplexy (an abrupt and reversible decrease in or loss of muscle tone, affecting the limbs or trunk or both, elicited by emotional stimuli). Narcolepsy has an adverse impact on peopl...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD003724.pub3
更新日期:2008-01-23 00:00:00
abstract:BACKGROUND:Previous systematic reviews and meta-analyses consistently show the positive effect of exercise-based rehabilitation for heart failure (HF) on exercise capacity; however, the direction and magnitude of effects on health-related quality of life, mortality and hospital admissions in HF remain less certain. Thi...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD003331.pub4
更新日期:2014-04-27 00:00:00
abstract:BACKGROUND:Vomiting caused by acute gastroenteritis is very common in children and adolescents. Treatment of vomiting in children can be problematic and the use of antiemetics remains a controversial issue. There have been concerns expressed about apparently unacceptable levels of side effects such as sedation and extr...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD005506.pub2
更新日期:2006-07-19 00:00:00
abstract:BACKGROUND:In women with preterm labor, tocolysis has not been shown to improve perinatal mortality; however, it is often given for 48 hours to allow for the corticosteroid effect for fetal maturation. In women with preterm premature rupture of membranes (PPROM), the use of tocolysis is still controversial. In theory, ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD007062.pub2
更新日期:2011-10-05 00:00:00
abstract:BACKGROUND:Cystic Fibrosis is characterised by chest infection, the antibiotic treatment of which has significantly improved the outlook for people with this condition. The unusual nature of organisms that infect the chest of individuals with cystic fibrosis has restricted antibiotic choice. In particular the bacteria,...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD002203
更新日期:2000-01-01 00:00:00
abstract:BACKGROUND:Hodgkin lymphoma (HL) is one of the most common haematological malignancies in young adults and, with cure rates of 90%, has become curable for the majority of individuals. Positron emission tomography (PET) is an imaging tool used to monitor a tumour's metabolic activity, stage and progression. Interim PET ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析
doi:10.1002/14651858.CD012643.pub3
更新日期:2020-01-13 00:00:00
abstract:BACKGROUND:Regional anaesthesia may reduce the rate of persistent (chronic) pain after surgery, a frequent and debilitating condition. OBJECTIVES:To compare local anaesthetics and regional anaesthesia versus conventional analgesia for the prevention of persistent pain six or 12 months after surgery. SEARCH METHODS:We...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD007105.pub2
更新日期:2012-10-17 00:00:00
abstract:BACKGROUND:Combination injectable contraceptives (CICs) provide a highly effective, reversible method of preventing pregnancy, and they do not require daily administration or use at the time of coitus. Although they are used in many countries, their acceptability could be limited by method characteristics, such as the ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:
更新日期:2013-01-01 00:00:00
abstract:BACKGROUND:A key component of many asthma management guidelines is the recommendation for patient education and regular medical review. A number of controlled trials have been conducted to measure the effectiveness of asthma education programmes. These programmes improve patient knowledge, but their impact on health ou...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD001005
更新日期:2000-01-01 00:00:00
abstract:BACKGROUND:Hepatitis C is a major cause of liver-related morbidity and mortality. Ribavirin plus interferon combination therapy is presently considered the optimal treatment of interferon naive patients with chronic hepatitis C, but its role in relapsers and non-responders to previous interferon therapy is not establis...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD002234.pub2
更新日期:2007-07-18 00:00:00
abstract:BACKGROUND:Breastfeeding is known to be the biological norm. Despite this, many women wean their babies because of perceived insufficient breast milk production. Mothers are sometimes advised to increase their fluid intake in the hope that this could improve breast milk production. The effect of extra fluid on human br...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD008758.pub2
更新日期:2014-06-11 00:00:00
abstract:BACKGROUND:In a previous Cochrane Review, we found that for women with metastatic breast cancer unselected for triple-negative disease, there is little or no survival benefit and excess toxicity from platinum-based regimens. In subgroup analyses, however, we found preliminary low-quality evidence of a survival benefit ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析
doi:10.1002/14651858.CD013750
更新日期:2020-10-21 00:00:00
abstract:BACKGROUND:Chronic non-specific cough is a chronic, dry cough of in the absence of identifiable respiratory disease or known aetiology. Although it is usually not reflective of an underlying severe illness, it does cause significant morbidity, and as such relief from it is often sought. The use of honey and lozenges to...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD007523.pub2
更新日期:2009-04-15 00:00:00
abstract:BACKGROUND:Hypertonic solutions are considered to have a greater ability to expand blood volume and thus elevate blood pressure and can be administered as a small volume infusion over a short time period. On the other hand, the use of hypertonic solutions for volume replacement may also have important disadvantages. O...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD002045.pub2
更新日期:2004-01-01 00:00:00
abstract:BACKGROUND:Acute respiratory infections (ARIs) comprise a large and heterogeneous group of infections including bacterial, viral and other aetiologies. In recent years, procalcitonin - the prohormone of calcitonin - has emerged as a promising marker for the diagnosis of bacterial infections and for improving decisions ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD007498.pub2
更新日期:2012-09-12 00:00:00
abstract:BACKGROUND:Chronic kidney disease (CKD) is defined as reduced function of the kidneys present for 3 months or longer with adverse implications for health and survival. For several decades low protein diets have been proposed for participants with CKD with the aim of slowing the progression to end-stage kidney disease (...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析
doi:10.1002/14651858.CD001892.pub5
更新日期:2020-10-29 00:00:00
abstract:BACKGROUND:Up to half the people with tuberculosis do not complete their treatment. Thus strategies that improve adherence to treatment regimens are important. OBJECTIVES:To compare policies of directly observed therapy with self treatment at home in people requiring treatment for clinically active tuberculosis, or re...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD003343
更新日期:2003-01-01 00:00:00