BACKGROUND & AIMS: The chemopreventive effects of Allium vegetables (onions, garlic, shallots, leeks, chives, and so forth) have been studied extensively, although their effect on gastric cancer risk is controversial. We performed a meta-analysis of cohort and case-control studies to analyze this association. METHODS: We searched MEDLINE for studies of Allium vegetable consumption and gastric cancer that were published in any language, from January 1, 1966, to September 1, 2010. We analyzed 19 case-control and 2 cohort studies, of 543,220 subjects. We pooled the relative risks from individual studies using a random-effects model and performed dose-response, heterogeneity, and publication bias analyses. RESULTS: In a pooled analysis of all studies, consumption of large amounts of Allium vegetables (in a comparison of the highest and lowest consumption groups) reduced the risk for gastric cancer (odds ratio, 0.54; 95% confidence interval, 0.43-0.65). Specific analyses for onion, garlic, leek, Chinese chive, scallion, garlic stalk, and Welsh onion yielded similar results, except for onion leaf. The estimated summary odds ratio for an increment of 20 g/day of Allium vegetables consumed (approximately the average weight of 1 garlic bulb) was 0.91 (95% confidence interval, 0.88-0.94), based on case-control studies from the dose-response meta-analysis. CONCLUSIONS: In a meta-analysis, consumption of high levels of Allium vegetables reduced the risk for gastric cancer risk. Because of potential confounding factors and exposure misclassification, further studies are required to establish this association.
BACKGROUND & AIMS: The chemopreventive effects of Allium vegetables (onions, garlic, shallots, leeks, chives, and so forth) have been studied extensively, although their effect on gastric cancer risk is controversial. We performed a meta-analysis of cohort and case-control studies to analyze this association. METHODS: We searched MEDLINE for studies of Allium vegetable consumption and gastric cancer that were published in any language, from January 1, 1966, to September 1, 2010. We analyzed 19 case-control and 2 cohort studies, of 543,220 subjects. We pooled the relative risks from individual studies using a random-effects model and performed dose-response, heterogeneity, and publication bias analyses. RESULTS: In a pooled analysis of all studies, consumption of large amounts of Allium vegetables (in a comparison of the highest and lowest consumption groups) reduced the risk for gastric cancer (odds ratio, 0.54; 95% confidence interval, 0.43-0.65). Specific analyses for onion, garlic, leek, Chinese chive, scallion, garlic stalk, and Welsh onion yielded similar results, except for onion leaf. The estimated summary odds ratio for an increment of 20 g/day of Allium vegetables consumed (approximately the average weight of 1 garlic bulb) was 0.91 (95% confidence interval, 0.88-0.94), based on case-control studies from the dose-response meta-analysis. CONCLUSIONS: In a meta-analysis, consumption of high levels of Allium vegetables reduced the risk for gastric cancer risk. Because of potential confounding factors and exposure misclassification, further studies are required to establish this association.
Authors: Haejin In; Marisa Langdon-Embry; Lauren Gordon; Clyde B Schechter; Judith Wylie-Rosett; Philip E Castle; M Margaret Kemeny; Bruce D Rapkin Journal: J Surg Res Date: 2018-04-03 Impact factor: 2.192
Authors: Melissa A Jim; Paulo S Pinheiro; Helena Carreira; David K Espey; Charles L Wiggins; Hannah K Weir Journal: Cancer Date: 2017-12-15 Impact factor: 6.860
Authors: Ya-si Xu; Jian-guo Feng; Dan Zhang; Bo Zhang; Min Luo; Dan Su; Neng-ming Lin Journal: Acta Pharmacol Sin Date: 2013-12-23 Impact factor: 6.150