Table 4.

Interplay between cruciferous vegetable intake (g/wk), GSTP1 and GSTA1 genotype, and the risk of colorectal adenomas in subgroups of meat consumption and smoking

Crucifer intake (g/wk)*n (cases/controls)
OR (95% CI), P for interaction
n (cases/controls)
OR (95% CI), P for interaction
≤129
>129
≤129
>129
≤129
>129
≤129
>129
Red meat (g/d)§≤53>53
All genotypes161/173161/17610.93 (0.66-1.30)175/176249/17311.36 (1.00-1.86)
    GSTP1
        GG17/1926/2411.44 (0.58-3.61)17/2430/1612.67 (1.07-6.69)
        AG65/8568/771.05 (0.48-2.28)0.97 (0.44-2.11)86/84115/701.39 (0.67-2.89)2.04 (0.98-4.22)
        AA78/6965/751.33 (0.61-2.89)1.08 (0.49-2.38)70/68101/871.34 (0.63-2.82)1.48 (0.72-3.04)
0.560.22
    GSTA1
        TT29/3028/3311.05 (0.48-2.28)24/3354/3012.36 (1.14-4.87)
        CT86/8764/761.12 (0.59-2.12)0.78 (0.40-1.51)80/82123/841.41 (0.74-2.67)2.01 (1.07-3.77)
        CC46/5667/670.85 (0.43-1.70)1.04 (0.53-2.02)67/6169/591.66 (0.86-3.22)1.66 (0.86-3.24)
0.300.16
Processed meat (g/d)
≤29
>29
All genotypes156/160189/18910.96 (0.69-1.33)180/189221/1601137 (1.00-1.88)
    GSTP1
        GG19/1828/2411.23 (0.50-3.03)15/2528/1613.25 (1.27-8.30)
        AG73/6879/891.11 (0.51-2.40)0.81 (0.38-1.75)78/101104/581.42 (0.68-2.98)2.87 (1.35-6.10)
        AA62/7479/760.87 (0.40-1.89)1.03 (0.48-2.22)86/6387/862.24 (1.05-4.75)1.66 (0.79-3.49)
0.320.0016
    GSTA1
        TT23/3342/3611.85 (0.88-3.89)30/3040/2711.41 (0.67-2.98)
        CT82/7981/871.69 (0.88-3.25)1.30 (0.68-2.51)84/89106/740.94 (0.50-1.75)1.36 (0.72-2.54)
        CC48/4863/661.47 (0.72-2.97)1.38 (0.70-2.72)65/6973/601.00 (0.53-1.91)1.27 (0.66-2.43)
0.140.92
Smoking
Never
Ever
All genotypes102/146146/16511.19 (0.82-1.73)234/202264/18411.16 (0.87-1.55)
    GSTP1
        GG12/1824/1513.32 (1.16-9.53)22/2532/2511.44 (0.64-3.26)
        AG48/7654/721.14 (0.48-2.71)1.17 (0.49-2.78)103/93129/751.28 (0.65-2.50)1.79 (0.91-3.50)
        AA40/5366/781.27 (0.52-3.09)1.34 (0.57-3.15)108/84100/841.46 (0.74-2.85)1.30 (0.66-2.57)
0.12**0.29
    GSTA1
        TT14/2431/3012.16 (0.88-5.30)39/3951/3311.37 (0.71-2.64)
        CT57/7165/801.45 (0.64-3.29)1.25 (0.56-2.75)109/98122/801.16 (0.67-2.01)1.45 (0.81-2.53)
        CC29/5248/550.96 (0.41-2.27)1.45 (0.64-3.32)84/6588/711.32 (0.74-2.35)1.26 (0.71-2.23)
0.140.59
  • * Mean cruciferous vegetable intake was 73.1 ± 36.3 and 70.3 ± 36.6 g/wk for cases and controls, respectively, in the lower-than-median intake group; and 242.5 ± 108.4 and 230.3 ± 109.2 g/wk, respectively, in the higher-than-median intake group.

  • Adjusted for age (in four categories: <45, <55, <65, <75), sex, energy intake, and folate intake.

  • Calculated as the LR test comparing the models with and without crucifer-by-genotype interaction terms.

  • § Fresh red meat consumption defined as sum of pork, beef and unclassified (non-organ) meats; consumption in the lower and higher category was 28.7 ± 15.2 and 82.1 ± 21.2 g/d, respectively.

  • Least active/expressed variant(s).

  • Processed meat defined as preserved and ready-to-eat meat products; consumption in the lower and higher category was 13.7 ± 8.2 and 57.8 ± 32.7 g/d, respectively.

  • ** Lemeshow goodness-of-fit test (P = 0.049).