Table 4.

Effects of alcohol and folate intake according to MTHFR 677 C>T genotype for the colorectal cancer and adenoma study

Colorectal cancer
Colorectal adenoma
CC/CT
TT
CC/CT
TT
Controls, n (%)Cases, n (%)OR (95% CI)*Controls, n (%)Cases, n (%)OR (95% CI)*Controls, n (%)Cases, n (%)OR (95% CI)*Controls, n (%)Cases, n (%)OR (95% CI)*
Alcohol intake54042148532692672741
    0215 (39.8)115 (27.3)1.0020 (41.7)23 (43.4)1.0065 (24.2)54 (20.2)1.0010 (37.0)8 (19.5)1.00
    1-13215 (39.8)157 (37.3)1.37 (1.00-1.88)21 (43.8)16 (30.2)0.53 (0.20-1.44)105 (39.0)104 (39.0)1.14 (0.72-1.80)10 (37.0)14 (34.2)1.88 (0.47-7.47)
    ≥14110 (20.4)149 (35.4)2.55 (1.73-3.76)7 (14.6)14 (26.4)1.63 (0.41-6.55)99 (36.8)109 (40.8)0.99 (0.59-1.66)7 (25.9)19 (46.3)3.83 (0.77-19.2)
    Overall trend1.58 (1.30-1.92)1.07 (0.56-2.07)0.99 (0.76-1.28)1.96 (0.88-4.38)
    Likelihood ratio, χ2 (df)1.15 (1), P = 0.281.45 (1), P = 0.23
Folate intake§53640748512692672741
    ≤276.07140 (26.1)101 (24.8)1.009 (18.9)15 (29.4)1.0071 (26.4)96 (36.0)1.004 (14.8)12 (29.3)1.00
    276.08-397.86261 (48.7)196 (48.2)1.04 (0.76-1.43)24 (50.0)25 (49.0)0.83 (0.29-2.39)122 (45.4)117 (43.8)0.71 (0.48-1.08)14 (51.9)24 (58.5)0.54 (0.14-2.04)
    ≥397.87135 (25.2)110 (27.0)1.15 (0.80-1.65)15 (31.3)11 (21.6)0.65 (0.19-2.18)76 (28.3)54 (20.2)0.53 (0.33-0.85)9 (33.3)5 (12.2)0.19 (0.04-0.91)
    Overall trend1.05 (0.93-1.18)0.87 (0.59-1.28)0.81 (0.70-0.95)0.57 (0.35-0.95)
    Likelihood ratio, χ2 (df)2.31 (1), P = 0.131.71 (1), P = 0.19
  • NOTE: Adjusted odds ratios and 95% CI.

    Abbreviation: df, degrees of freedom.

  • * Adjusted by sex and age.

  • Alcohol consumption (U/wk) at 40 y of age, with limits based on quartiles derived from population controls.

  • Test of interaction between alcohol consumption and MTHFR 677 using the likelihood ratio test based on the trend model.

  • § Folate intake derived from nutrient analysis, including folate supplements but excluding folate from alcohol.