TABLE 2.
HRs and 95% CIs for quintiles of intakes of whole grains and dietary fiber and colorectal cancer1
| Quintile 1 | Quintile 2 | Quintile 3 | Quintile 4 | Quintile 5 | P-trend2 | |
|---|---|---|---|---|---|---|
| Whole grains | ||||||
| Median intake, servings . 1000 kcal−1 . d−1 | 0.2 | 0.4 | 0.6 | 0.8 | 1.3 | |
| Cases/person-years | 2417/1,265,611 | 2111/1,293,497 | 2009/1,297,815 | 1882/1,304,937 | 1781/1,302,670 | |
| Age- and sex-adjusted | 1.00 | 0.86 (0.81, 0.91) | 0.81 (0.76, 0.86) | 0.74 (0.69, 0.78) | 0.69 (0.64, 0.73) | <0.0001 |
| Multivariable adjusted3 | 1.00 | 0.93 (0.87, 0.98) | 0.91 (0.86, 0.97) | 0.86 (0.81, 0.92) | 0.83 (0.78, 0.89) | <0.0001 |
| Multivariable adjusted with folate4 | 1.00 | 0.93 (0.88, 0.99) | 0.92 (0.86, 0.98) | 0.87 (0.82, 0.93) | 0.84 (0.79, 0.90) | <0.0001 |
| Multivariable adjusted with folate and fiber5 | 1.00 | 0.94 (0.88, 1.00) | 0.92 (0.87, 0.98) | 0.88 (0.82, 0.94) | 0.84 (0.78, 0.90) | <0.0001 |
| Dietary fiber | ||||||
| Median intake, g . 1000 kcal−1 . d−1 | 6.4 | 8.5 | 10.3 | 12.3 | 15.9 | |
| Cases/person-years | 2428/1,260,591 | 2107/1,289,753 | 2018/1,298,864 | 1826/1,305,506 | 1821/1,309,813 | |
| Age- and sex-adjusted | 1.00 | 0.83 (0.78, 0.88) | 0.78 (0.74, 0.83) | 0.70 (0.66, 0.75) | 0.70 (0.66, 0.75) | <0.0001 |
| Multivariable adjusted3 | 1.00 | 0.91 (0.86, 0.97) | 0.92 (0.86, 0.98) | 0.87 (0.81, 0.93) | 0.92 (0.86, 0.99) | 0.027 |
| Multivariable adjusted with folate4 | 1.00 | 0.93 (0.87, 0.99) | 0.94 (0.87, 1.00) | 0.89 (0.83, 0.96) | 0.96 (0.88, 1.04) | 0.396 |
n = 478,994.
P-trend < 0.05. All statistical tests were 2-sided.
Estimated using a Cox proportional hazards regression model (model 1) adjusted for age (years, continuous), BMI (kg/m2) (<18.5; 18.5 to <25; 25 to <30; ≥30; missing), alcohol intake (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), and total energy (continuous).
Adjusted for all covariates in model 1 and dietary folate (quintiles).
Adjusted for all covariates in models 1 and 2 and dietary fiber (quintiles).