Table 5.

Multivariate-adjusted RRs (95% CIs) of colorectal, colon, and rectal cancer by tertiles of heme iron intake according to tertiles of dietary intake of chlorophyll, total vegetable consumption, consumption frequency of green leafy vegetables, and alcohol consumption among women

Heme iron, mg/d (median)
Colorectal cancer
Colon cancer
Rectal cancer
Tertile 1 (0.53)Tertile 2 (0.91)Tertile 3 (1.47)Tertile 1 (0.53)Tertile 2 (0.91)Tertile 3 (1.47)Tertile 1 (0.53)Tertile 2 (0.91)Tertile 3 (1.47)
Chlorophyll, mg/d (median intake)
    Tertile 3 (84)1 (Reference)1.13 (0.73-1.75)1.21 (0.80-1.84)1 (Reference)0.99 (0.61-1.60)0.96 (0.60-1.54)1 (Reference)1.65 (0.73-3.76)2.23 (1.04-4.79)
    Tertile 2 (48)1.08 (0.71-1.66)1.32 (0.88-2.00)1.43 (0.94-2.19)0.98 (0.61-1.57)1.24 (0.79-1.96)1.27 (0.79-2.04)1.51 (0.68-3.36)1.55 (0.70-3.44)2.11 (0.97-4.60)
    Tertile 1 (25)1.12 (0.74-1.70)1.23 (0.81-1.86)1.10 (0.71-1.69)1.07 (0.67-1.69)1.21 (0.77-1.92)1.04 (0.64-1.68)1.40 (0.63-3.11)1.17 (0.52-2.66)1.40 (0.61-3.21)
Vegetables, g/d (median intake)
    Tertile 3 (284)1 (Reference)0.94 (0.61-1.43)1.11 (0.74-1.66)1 (Reference)0.92 (0.58-1.48)0.96 (0.61-1.53)1 (Reference)0.86 (0.40-1.85)1.43 (0.73-2.77)
    Tertile 2 (184)0.78 (0.51-1.19)1.17 (0.78-1.75)0.97 (0.64-1.48)0.75 (0.46-1.21)1.15 (0.73-1.81)0.92 (0.58-1.48)0.80 (0.38-1.70)1.08 (0.54-2.16)1.07 (0.53-2.18)
    Tertile 1 (117)0.97 (0.65-1.45)1.02 (0.68-1.53)1.08 (0.71-1.65)1.01 (0.65-1.58)1.04 (0.66-1.64)1.04 (0.65-1.69)0.75 (0.36-1.57)0.81 (0.39-1.68)1.13 (0.55-2.32)
Alcohol consumption, g/d (median)*
    01 (Reference)1.65 (1.13-2.42)1.24 (0.83-1.86)1 (Reference)1.91 (1.24-2.95)1.26 (0.79-2.01)1 (Reference)0.93 (0.47-1.83)1.20 (0.63-2.30)
    0.1-4.9 (1.9)1.11 (0.75-1.64)1.02 (0.69-1.52)1.08 (0.72-1.64)1.36 (0.88-2.10)1.02 (0.64-1.61)1.10 (0.68-1.77)0.52 (0.24-1.12)0.99 (0.51-1.90)1.02 (0.52-2.03)
    ≥5 (17)1.18 (0.76-1.81)1.15 (0.76-1.73)1.48 (1.00-2.19)1.24 (0.76-2.04)1.26 (0.79-2.00)1.50 (0.95-2.36)1.05 (0.51-2.15)0.82 (0.40-1.68)1.41 (0.76-2.61)
  • NOTE: Adjusted for age at baseline (y), BMI (kg/m2), family history of colorectal cancer (yes, no), cigarette smoker (never, former, current), nonoccupational physical activity (<30, 30-60, 60-90, >90 min/d), total energy intake (kJ), and consumption of alcohol (except for analysis of alcohol). Green leafy vegetables include spinach, endive (cooked and raw), kale, and lettuce.

  • * Additional adjustment for total vegetable consumption (g/d).