Refined grains consumption is associated with a greater odds of glioma.

Objective: Grain consumption has been associated with brain carcinogenesis in earlier studies, however, no data are available examining the association between refined grains consumption and risk of glioma. The current study was done to investigate the association between refined grains consumption and risk of glioma in Iranian adults.Methods: This hospital-based case-control study was performed on 128 pathologically confirmed cases with glioma and 256 age- and sex-matched controls in Tehran, Iran. Dietary intakes of participants including refined grains consumption were collected using a validated Block-format 123-item detailed food frequency questionnaire (FFQ). Refined grains were considered as the sum of white breads, pasta, rice, boiled and fried potato, sweets, and cookies.Results: A significant positive association was found between refined grains consumption and glioma (OR: 3.51, 95% CI: 1.97-6.26, P_trend <0.001). This association did not change after adjustment for energy intake (OR: 4.30, 95% CI: 2.27-8.15, P_trend <0.001). After controlling for potential confounders, those in the top tertile of refined grains consumption were significantly more likely to have glioma than those in the bottom tertile (OR: 2.92, 95% CI: 1.38-6.17, P_trend = 0.007). This significant association remained unchanged, even after further adjustment for other dietary variables (OR: 2.54, 95% CI: 1.15-5.63, P_trend = 0.02) and BMI (OR: 2.49, 95% CI: 1.12-5.53, P_trend = 0.03).Conclusion: We found a significant positive association between refined grains consumption and odds of glioma. Further prospective cohort studies are needed to confirm these findings.