title: Meta-analysis: antioxidant supplements for liver diseases - the Cochrane Hepato-Biliary Group.
abstract: BACKGROUND
  Several liver diseases have been associated with oxidative stress. Accordingly, antioxidants have been suggested as potential therapeutics for various liver diseases. The evidence supporting these suggestions is equivocal.
  
  
  OBJECTIVE
  To assess the benefits and harms of antioxidant supplements for patients with liver diseases.
  
  
  METHODS
  We identified trials through electronic and manual searches until August 2009. We included randomized trials comparing antioxidant supplements (beta-carotene, vitamin A, C, E and selenium) vs. placebo or no intervention for autoimmune liver diseases, viral hepatitis, alcoholic liver disease and cirrhosis (any aetiology). Random-effects and fixed-effect meta-analyses were conducted. Results were presented as relative risks (RR), or mean difference (MD), both with 95% confidence intervals (CI).
  
  
  RESULTS
  Twenty randomized trials with 1225 participants were included. The trials assessed beta-carotene (3 trials), vitamin A (2 trials), vitamin C (9 trials), vitamin E (15 trials) and selenium (8 trials). The majority of the trials had high risk of bias and showed heterogeneity. Overall, the assessed antioxidant supplements had no significant effect on all-cause mortality [relative risk (RR) 0.84, 95% confidence interval (CI) 0.60-1.19, I(2) = 0%] or liver-related mortality (RR 0.89, 95% CI 0.39-2.05, I(2) = 37%). Stratification according to the type of liver disease assessed did not affect the conclusions. Antioxidant supplements significantly increased the activity of gamma glutamyl transpeptidase (MD 24.21 IU/L, 95% CI 6.67-41.75, I(2) = 0%).
  
  
  CONCLUSIONS
  We found no evidence to support or refute antioxidant supplements in patients with liver disease. Antioxidant supplements may increase liver enzymes.
authors.affiliation: Centre for Clinical Intervention Research, Copenhagen University Hospital, Rigshospitalet, Denmark. goranb@junis.ni.ac.rs
authors.forename: G
authors.initials: G
authors.lastname: Bjelakovic
authors.forename: L L
authors.initials: LL
authors.lastname: Gluud
authors.forename: D
authors.initials: D
authors.lastname: Nikolova
authors.forename: M
authors.initials: M
authors.lastname: Bjelakovic
authors.forename: A
authors.initials: A
authors.lastname: Nagorni
authors.forename: C
authors.initials: C
authors.lastname: Gluud
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage; D015982:Bias; D005260:Female; D006801:Humans; D008107:Liver Diseases / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D012643:Selenium / Q000008:administration & dosage; D014801:Vitamin A / Q000008:administration & dosage; D014810:Vitamin E / Q000008:administration & dosage; D019207:beta Carotene / Q000008:administration & dosage
chemical_list: D000975:Antioxidants; D019207:beta Carotene; D014801:Vitamin A; D014810:Vitamin E; D012643:Selenium; D001205:Ascorbic Acid