Association between dietary vitamin C intake and risk of esophageal cancer: A dose-response meta-analysis

Int J Cancer. 2016 Apr 15;138(8):1843-50. doi: 10.1002/ijc.29838. Epub 2015 Oct 15.


While several epidemiological studies have investigated the association between vitamin C and risk of esophageal cancer, the results remain inconsistent. In the present study, a meta-analysis was conducted to assess the impact of dietary vitamin C intake on esophageal cancer risk. Online databases were searched up to March 29, 2015, for studies on the association between dietary vitamin C intake and esophageal cancer risk. Pooled risk ratios (RRs) or odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Dose-response analyses were performed using the method of restricted cubic splines with four knots at percentiles of 5, 35, 65 and 95% of the distribution. Publication bias was estimated using Egger's tests and funnel plots. In all, 15 articles were included in this meta-analysis, including 20 studies, containing 7063 controls and 3955 cases of esophageal cancer. By comparing the highest vs. the lowest categories of vitamin C intake, we found that vitamin C was inversely associated with the risk of esophageal cancer [overall OR = 0.58, 95% CI = 0.49-0.68, I(2) = 56%]. A linear dose-response relationship was found. With an increase in dietary vitamin C intake of 50 mg/day, the risk of esophageal cancer statistically decreased by 13% (OR = 0.87, 95% CI = 0.80-0.93, p(linearity) = 0.0002). In conclusion, our analysis suggested that the higher intake of dietary vitamin C might have a protective effect against esophageal cancer.

Keywords: dietary vitamin C; dose-response; esophageal cancer; intake; meta-analysis.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ascorbic Acid / administration & dosage*
  • Diet
  • Dose-Response Relationship, Drug
  • Esophageal Neoplasms / epidemiology*
  • Humans
  • Odds Ratio
  • Risk Factors
  • Vitamins / administration & dosage*


  • Vitamins
  • Ascorbic Acid