TABLE 2.
Relative risks and 95% CIs of total cancer according to quintiles of flavonoid intake
| Quintiles of intake |
||||||
| 1 | 2 | 3 | 4 | 5 | P for linear trend1 | |
| Total quantified flavonoid | ||||||
| Median (mg/d) | 8.88 | 13.91 | 19.13 | 27.24 | 47.44 | |
| Range (mg/d) | 0–11.55 | 11.56–16.30 | 16.31–22.53 | 22.54–34.54 | 34.55–236.38 | |
| Cases/person-years | 665/88,485 | 670/88,645 | 631/88,692 | 631/88,157 | 637/88,322 | |
| Adjusted for age, race, energy, treatment2 | 1.00 (reference) | 0.99 (0.89, 1.10) | 0.91 (0.82, 1.02) | 0.90 (0.81, 1.01) | 0.93 (0.83, 1.03) | 0.14 |
| Multivariate adjusted3 | 1.00 (reference) | 1.00 (0.89, 1.12) | 0.93 (0.82, 1.05) | 0.94 (0.83, 1.07) | 0.97 (0.86, 1.10) | 0.72 |
| Myricetin | ||||||
| Median (mg/d) | 0.15 | 0.47 | 0.77 | 1.33 | 2.83 | |
| Range (mg/d) | 0–0.34 | 0.35–0.60 | 0.61–1.00 | 1.01–1.84 | 1.85–19.92 | |
| Cases/person-years | 660/87,711 | 692/89,640 | 637/88,169 | 621/88,751 | 624/88,031 | |
| Adjusted for age, race, energy, treatment2 | 1.00 (reference) | 1.00 (0.90, 1.11) | 0.95 (0.85, 1.06) | 0.90 (0.80, 1.00) | 0.93 (0.84, 1.04) | 0.14 |
| Multivariate adjusted3 | 1.00 (reference) | 1.03 (0.92, 1.15) | 0.98 (0.87, 1.10) | 0.95 (0.84, 1.06) | 1.00 (0.89, 1.13) | 0.83 |
| Kaempferol | ||||||
| Median (mg/d) | 0.86 | 1.80 | 3.31 | 5.68 | 13.06 | |
| Range (mg/d) | 0–1.25 | 1.26–2.55 | 2.56–4.33 | 4.34–7.88 | 7.89–99.72 | |
| Cases/person-years | 702/88,612 | 645/88,205 | 600/88,781 | 658/88,414 | 629/88,289 | |
| Adjusted for age, race, energy, treatment2 | 1.00 (reference) | 0.92 (0.83, 1.02) | 0.84 (0.76, 0.94) | 0.93 (0.84, 1.04) | 0.91 (0.82, 1.02) | 0.46 |
| Multivariate adjusted3 | 1.00 (reference) | 0.96 (0.85, 1.07) | 0.88 (0.79, 0.99) | 0.98 (0.88, 1.10) | 0.97 (0.86, 1.08) | 0.91 |
| Quercetin | ||||||
| Median (mg/d) | 6.49 | 10.19 | 13.62 | 19.21 | 32.79 | |
| Range (mg/d) | 0–8.52 | 8.53–11.84 | 11.85–15.92 | 15.93–24.26 | 24.27–229.2 | |
| Cases/person-years | 669/88,497 | 634/88,941 | 660/88,273 | 638/88,405 | 633/88,186 | |
| Adjusted for age, race, energy, treatment2 | 1.00 (reference) | 0.93 (0.83, 1.04) | 0.95 (0.85, 1.06) | 0.91 (0.81, 1.01) | 0.91 (0.81, 1.01) | 0.12 |
| Multivariate adjusted3 | 1.00 (reference) | 0.92 (0.82, 1.04) | 0.96 (0.85, 1.08) | 0.94 (0.83, 1.06) | 0.94 (0.83, 1.07) | 0.64 |
| Luteolin | ||||||
| Median (mg/d) | 0.01 | 0.04 | 0.05 | 0.08 | 0.20 | |
| Range (mg/d) | 0–0.02 | 0.03–0.04 | 0.05–0.06 | 0.07–0.13 | 0.14–2.02 | |
| Cases/person-years | 706/98,527 | 584/82,146 | 728/98,794 | 565/77,080 | 651/85,755 | |
| Adjusted for age, race, energy, treatment2 | 1.00 (reference) | 0.98 (0.88, 1.10) | 1.00 (0.90, 1.11) | 0.98 (0.88, 1.10) | 1.01 (0.90, 1.12) | 0.83 |
| Multivariate adjusted3 | 1.00 (reference) | 1.00 (0.89, 1.12) | 1.03 (0.92, 1.15) | 1.03 (0.91, 1.16) | 1.07 (0.95, 1.22) | 0.23 |
| Apigenin | ||||||
| Median (mg/d) | 0.13 | 0.29 | 0.43 | 0.66 | 1.35 | |
| Range (mg/d) | 0–0.22 | 0.23–0.35 | 0.36–0.51 | 0.52–0.92 | 0.93–16.81 | |
| Cases/person-years | 663/89,741 | 652/85,704 | 626/91,287 | 637/87,451 | 656/88,118 | |
| Adjusted for age, race, energy, treatment2 | 1.00 (reference) | 1.01 (0.91, 1.13) | 0.94 (0.84, 1.05) | 0.99 (0.88, 1.10) | 0.93 (0.84, 1.04) | 0.18 |
| Multivariate adjusted3 | 1.00 (reference) | 1.07 (0.95, 1.20) | 0.98 (0.88, 1.10) | 1.04 (0.92, 1.16) | 0.99 (0.87, 1.12) | 0.61 |
Linear trends were tested by using the median value of each intake category as an ordinal variable.
Model adjusted for age (continuous), race (white, nonwhite), total energy intake (continuous), and randomized treatment assignment (aspirin, vitamin E, β-carotene, or corresponding placebos).
Model additionally adjusted for smoking (never; former; current, <15 cigarettes/d; current, ≥15 cigarettes/d); alcohol use (0, >0 to <5, 5 to <15, ≥15 g/d); physical activity (<200, 200 to <600, 600 to <1500, ≥1500 kcal/wk); postmenopausal status (yes, no, uncertain); hormone replacement therapy use (never, former, current); multivitamin use (never, former, current); BMI (continuous); family history of colorectal cancer, ovary cancer, and breast cancer (yes, no); and intake of fruit and vegetables, fiber, folate, and saturated fat (continuous).