Dietary fiber and stomach cancer risk : a case-control study from Italy

Objective: Fiber intake has been inversely related to stomach cancer risk, although this issue is still controversial. Methods: A case-control study was conducted in Italy between 1997 and 2007, including 230 cases with incident, histologically confirmed stomach cancer, and 547 controls with acute, non-neoplastic diseases. Dietary habits were investigated through a validated food frequency questionnaire. Results: Compared with the lowest quintile of intake, the multivariate odds ratios (ORs, including terms for major recognised confounding factors and total energy intake) for the highest quintile were 0.47 (95% confidence interval (CI): 0.28-0.79) for total fiber, 0.50 (95% CI: 0.30-0.85) for soluble non-cellulose polysaccharides (NCP), 0.39 (95% CI: 0.23-0.66) for total insoluble fiber, 0.54 (95% CI: 0.32-0.91) for insoluble NCP, 0.37 (95% CI: 0.22-0.64) for cellulose, and 0.59 (95% CI: 0.36-0.98) for lignin. With reference to the sources of fiber, an inverse association was found for fiber from vegetable (OR = 0.42, 95% CI: 0.24-0.72), and to a lesser extent from fruit (OR = 0.65, 95% CI: 0.38-1.10), but not for fiber from grain (OR = 1.25, 95% CI: 0.77-2.03). Conclusions: This study found an inverse relationship between stomach cancer risk and various types of fiber, derived, in particular, from vegetables and fruit