Dietary fiber and grain consumption in relation to head and neck cancer in the NIH-AARP Diet and Health Study

Background Dietary fiber and grain consumption may reduce the risk of head and neck cancer; however, the epidemiological evidence is limited. We investigated this relationship in the National Institutes of Health (NIH)-AARP Diet and Health Study. Methods Cox proportional hazards models were used to calculate multivariable hazard ratios (HR) and 95% confidence intervals (CI) to investigate dietary fiber and grain intake in relation to head and neck cancer. Results During approximately 11 years of follow-up, 1,867 (401 women/1,466 men) cases of head and neck cancer were diagnosed. Our data indicated that the relationship between fiber and grain intake and head and neck cancer is modified by sex (p-interactions < 0.001 and 0.001, respectively). Women with higher intake of total fiber and total grains had a lower risk of head and neck cancer (HR10g/day = 0.77, 95% CI = 0.64-0.93; HRserving/1,000kcal = 0.89, 95% CI = 0.80-0.99, respectively); this inverse relation was consistent across subtypes of fiber and grains. Conversely in men, the inverse associations were weaker and nonsignificant. Conclusions In the largest prospective cohort study to investigate this relation to date, intake of total fiber and grain foods was inversely associated with head and neck cancer incidence among women, but not among men.