FIGURE 1.

Associations for type (i.e., insoluble and soluble) and source of dietary fiber (i.e., fruits, vegetables, beans, and grains) intake with risk of colorectal cancer, using quintile 1 as the reference, in the NIH-AARP Diet and Health Study (n = 478,994). ¹Quintiles of dietary fiber intake (median g ^. 1000 kcal^{−1 .} d⁻¹). ²P-trend < 0.05. All statistical tests were 2-sided. ³P-nonlinear < 0.05. ⁴Cox proportional hazard model adjusted for age (continuous), BMI (in kg/m²) (<18.5; 18.5 to <25; 25 to <30; ≥30; missing), alcohol (0 drinks/d; <1 drink/d; 1 to <2 drinks/d; 2 to <3 drinks/d; ≥3 drinks/d; missing), general health status (excellent; very good; good; fair; poor; unknown), first-degree relatives with colon cancer (yes; no; unknown), race/ethnicity (non-Hispanic white; non-Hispanic black; Hispanic; Asian, Pacific Islander, or American Indian/Native American; unknown), education (<12 y; 12 y or completed high school; post–high school training other than college; some college; college and postgraduate; unknown), sex, physical activity (never, rarely; <3 times/mo; 1–2, 3–4, or ≥5 times/wk; missing), smoking (never; ≤20 cigarettes/d in the past; >20 cigarettes/d in the past; ≤20 cigarettes/d currently; >20 cigarettes/d currently; missing), and intakes of red and processed meat (quintiles), dietary calcium (quintiles), folate (quintiles), and total energy (continuous).