Colorectal cancer and adenomatous polyps in relation to allium vegetables intake: a meta-analysis of observational studies

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#adenomatous-polyps #allium #colorectal-neoplasms #diet #humans

Colorectal cancer and adenomatous polyps in relation to allium vegetables intake: a meta-analysis of observational studies

Turati et al., 2014 | Mol Nutr Food Res | Meta Analysis

Citation

Turati Federica, Guercio Valentina, ... Galeone Carlotta. Colorectal cancer and adenomatous polyps in relation to allium vegetables intake: a meta-analysis of observational studies. Mol Nutr Food Res. 2014-Sep;58(9):1907-14. doi:10.1002/mnfr.201400169

Abstract

SCOPE: To provide updated quantitative estimates of the associations between allium vegetables intake and risk of colorectal cancer and colorectal adenomatous polyps. METHODS AND RESULTS: We combined all published data on the issue, using a meta-analytic approach. Pooled relative risks (RRs) were calculated using random-effects models. Sixteen studies (13 333 cases) were included in the meta-analyses of colorectal cancer. Seven studies provided information on garlic, six on onion, and four on total allium vegetables. The pooled RRs of colorectal cancer for the highest versus the lowest category of intake were 0.85 (95% confidence interval; CI, 0.72-1.00) for garlic (0.76 for case-control, 0.99 for cohort studies), 0.85 (95% CI, 0.70-1.04) for onion (0.74 for case-control, 1.04 for cohort studies), and 0.78 (95% CI, 0.56-1.08) for total allium vegetables. Significant heterogeneity was found for the three meta-analyses. The pooled RR of colorectal adenomatous polyps for the highest versus the lowest category of total allium vegetables intake was 0.88 (95% CI, 0.80-0.98, three studies), with no heterogeneity. CONCLUSION: High garlic intake may reduce the risk of colorectal cancer. However, evidence of such protection derived mainly from case-control studies. High intake of total allium vegetables may be associated with a risk reduction of colorectal adenomatous polyps.

Key Findings

We combined all published data on the issue, using a meta-analytic approach. Pooled relative risks (RRs) were calculated using random-effects models. Sixteen studies (13 333 cases) were included in the meta-analyses of colorectal cancer. Seven studies provided information on garlic, six on onion, and four on total allium vegetables. The pooled RRs of colorectal cancer for the highest versus the lowest category of intake were 0.85 (95% confidence interval; CI, 0.72-1.00) for garlic (0.76 for case

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size See abstract
Age Range See abstract
Condition See abstract

MeSH Terms

  • Adenomatous Polyps
  • Allium
  • Colorectal Neoplasms
  • Diet
  • Humans
  • Observational Studies as Topic
  • Vegetables

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Research Support, Non-U.S. Gov't
  • Vertical: garlic

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09