Fiber intake has been inversely related to stomach cancer risk, although this issue is still controversial.
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.
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).
This study found an inverse relationship between stomach cancer risk and various types of fiber, derived, in particular, from vegetables and fruit.