(HealthDay News) — Dietary fiber intake is inversely associated with gastric cancer risk and is likely independent of conventional risk factors, according to a meta-analysis published in the July issue of Gastroenterology.
Zhizhong Zhang, from the Nanjing University School of Medicine in China, and colleagues conducted a literature review to identify case-control and cohort studies that assessed the correlation between dietary fiber intake and gastric cancer risk. Twenty-one articles were analyzed, which included 580,064 subjects. Summary relative risks were estimated using random-effects models.
The researchers found that, for the highest versus the lowest dietary fiber intake, the summary odds ratios of gastric cancer was 0.58, with significant heterogeneity identified among studies (I², 62.2 percent). Consistent results were seen on stratified analysis accounting for study design, geographic area, source and type of fiber, Lauren’s classification, publication year, sample size, and study quality score. A significant, 44 percent reduction in gastric cancer risk was seen for each 10-g/day increment in fiber intake. Similar results were seen on restriction of sensitivity analysis to studies controlling for conventional risk factors. There was little effect on the combined risk estimate with omission of any single study.
“In a meta-analysis, we show that dietary fiber intake is associated inversely with gastric cancer risk; the effect probably is independent of conventional risk factors,” the authors write. “The direction of the protective association of dietary fiber was consistent among all studies, but the absolute magnitude was less certain because of heterogeneity among the studies.”