Table 1.
Description of mean daily intake of nitrate in food and drinking water and estimated total nitrate intake, as well as the distribution of potential confounding factors: the Netherlands Cohort Study, 1986–1995.
| Exposure variable | Cases | Subcohort |
|---|---|---|
| Nitrate from food (mg/day) | 104.5 ± 43.4 | 104.5 ± 44.0 |
| Nitrate from drinking water (mg/day) | 5.3 ± 6.2 | 4.9 ± 6.2 |
| Total nitrate intake | 109.8 ± 44.3 | 109.4 ± 45.2 |
| Potential risk factors | ||
| Age (years) | 62.5 ± 4.1 | 61.4 ± 4.2 |
| Alcohol intake (g/day) | 15.8 ± 17.9 | 10.4 ± 14.4 |
| Coffee consumption (cups/day) | 5.9 ± 3.0 | 5.4 ± 2.7 |
| Tea consumption (cups/day) | 3.0 ± 2.5 | 3.5 ± 2.5 |
| Water consumption (L/day) | 2.1 ± 0.5 | 2.1 ± 0.5 |
| Total vegetable consumption (g/day) | 190.8 ± 79.4 | 193.4 ± 83.0 |
| Total fruit consumption (g/day) | 154.3 ± 122.4 | 175.5 ± 119.5 |
| Vitamin C intake (mg/day) | 98.7 ± 43.8 | 103.3 ± 43.8 |
| Vitamin E intake (mg/day) | 14.1 ± 6.3 | 13.4 ± 6.2 |
| Smoking amount (cigarettes/day)a | 17.8 ± 11.1 | 15.2 ± 10.2 |
| Smoking duration (years)a | 37.1 ± 11.6 | 31.7 ± 12.3 |
| Sex (% male)b | 766 (86.2) | 2,166 (49.1) |
| Cigarette smoking (% ever)b | 780 (87.7) | 2,827 (64.1) |
| Current cigarette smoking (% yes)b | 393 (44.2) | 1,250 (28.1) |
| Family history of bladder cancer (% yes)b | 10 (1.1) | 85 (1.9) |
| High risk occupation (% yes)b | 7 (0.8) | 17 (0.4) |
Values shown are mean ± SD, except where indicated.
a
Among ever smokers only.
b
Values shown are number (%).