Table 5

Association between MTHFR genotype and adenomatous polyps, stratified by dietary intakes (n = 1103)a

Nutrient intakes from both diet and supplementsGenotype
CC (247/297)bCT (208/252)bTT (48/69)b
Folate
 High1.0 (ref)0.9 (0.6–1.5)0.7 (0.3–1.3)
 Medium1.1 (0.7–1.7)0.8 (0.5–1.3)0.7 (0.3–1.5)
 Low0.9 (0.5–1.4)0.9 (0.6–1.6)1.5 (0.6–3.5)
  P for inter-tertile slopeP = 0.58P = 0.92P = 0.17
  P for interactioncP = 0.30
Vitamin B12
 High1.0 (ref)0.9 (0.6–1.5)0.6 (0.3–1.3)
 Medium1.4 (0.9–2.4)1.0 (0.6–1.7)1.0 (0.4–2.3)
 Low1.4 (0.8–2.3)1.6 (0.9–2.8)2.0 (0.9–4.4)
  P for inter-tertile slopeP = 0.28P = 0.05P = 0.03
  P for interactioncP = 0.29
Vitamin B6
 High1.0 (ref)0.8 (0.5–1.2)0.7 (0.4–1.4)
 Medium1.4 (1.0–2.1)1.1 (0.7–1.7)0.5 (0.2–1.3)
 Low1.3 (0.8–2.4)1.2 (0.8–1.9)2.1 (1.0–4.6)
  P for inter-tertile slopeP = 0.37P = 0.08P = 0.03
  P for interactioncP = 0.27
Methionine
 High1.0 (ref)0.7 (0.5–1.1)0.6 (0.3–1.3)
 Medium1.1 (0.6–1.8)0.9 (0.5–1.5)0.7 (0.3–1.6)
 Low0.9 (0.5–1.8)1.1 (0.6–2.2)1.4 (0.6–3.3)
  P for inter-tertile slopeP = 0.49P = 0.23P = 0.17
  P for interactioncP = 0.14
Alcohol
 None1.0 (ref)1.2 (0.8–1.8)1.6 (0.9–2.9)
 Medium1.4 (0.9–2.2)1.1 (0.7–1.7)0.7 (0.3–1.9)
 High1.9 (1.2–3.0)1.4 (0.9–2.1)0.8 (0.3–1.8)
  P for inter-tertile slopeP = 0.005P = 0.61P = 0.10
  P for interactioncP = 0.02
  • a Multivariate adjustment for age, sex, BMI, hormone replacement therapy (yes/no), percentage of kilocalories from fat, dietary fiber, folate, vitamin B12, vitamin B6, methionine, and alcohol, where appropriate.

  • b n cases/n controls.

  • c Testing for different slopes associated with nutrient intake across genotypes. Cutpoints for tertiles of dietary intakes, per day: folate, 268 μg/434 μg; vitamin B12, 5.09 μg/9.35 μg; vitamin B6, 1.94 mg/3.06 mg; methionine, 1.54 g/2.18 g); alcohol, 0 g/7 g.