Table 4.

Adjusted PMD and 95% CI according to combined levels of green tea intake and dietary soy isoflavones in all subjects and postmenopausal women

Soy isoflavones (mg/d)Non-green tea drinker
Green tea drinker
Total*
n
Mean (95% CI) PMD
n
Mean (95% CI) PMD
All subjects
Q1 + Q2 + Q31,24921.9 (21.0-22.8)58319.4 (18.1-20.7)21.1 (20.3-22.5)
Q431120.9 (19.1-22.8)21819.5 (17.3-21.7)20.5 (19.0-20.6)
Total21.7 (20.9-22.5)19.5 (18.3-20.6)

Postmenopausal women§

Q1 + Q2 + Q31,13020.7 (19.7-21.6)53118.3 (16.9-19.7)19.9 (19.1-20.7)
Q429220.2 (18.2-22.1)19318.4 (16.1-20.8)19.6 (18.1-21.1)
Total20.5 (19.7-21.4)18.4 (17.2-19.5)
  • NOTE: Adjusted for age at mammography, BMI at mammography (kg/m2), education(no formal education, primary school, secondary school, A level/university), parity (0,1-2, 3-4, ≥5), total calories (kcal), and menopausal status (pre, post, in analysis for all subjects).

  • * Tea-adjusted PMD (95% CI) for low (Q1 + Q2 + Q3) versus high (Q4) soy intake. P (low soy versus high soy) = 0.52 for all subjects and 0.76 for postmenopausal women only.

  • This analysis included 2,361 subjects after excluding 954 subjects who drank black tea.

  • Soy-adjusted PMD (95% CI) for non-green tea drinker and green tea drinker. P (non-green tea versus green tea) = 0.002 for all subjects and 0.003 for postmenopausal women only. Dietary soy did not modify the green tea MD association (Pinteraction = 0.30, all subjects).

  • § This analysis included 2,171 postmenopausal women after excluding 849 who drank black tea. Analyses of joint effects of soy and tea were not examined separately in premenopausal women because of the relatively small numbers in some of the cells.