Table 1.

Descriptive characteristics of study sample (n = 224)

All participants (n = 224)Equol nonproducer (n = 149)Equol producer (n = 75)Pa
Mean (SD)
Age (y)46.4 (4.7)46.5 (4.6)46.2 (5.0)0.63
Length of U.S. residence (y)10.2 (4.7)10.4 (4.7)9.8 (4.8)0.34
General Ethnicity Questionnaire – American version score2.2 (0.6)2.2 (0.6)2.2 (0.7)0.38
BMI (kg/m2)b23.7 (2.9)23.6 (3.0)23.8 (2.9)0.71
Age at menarche (y)14.9 (1.6)15.0 (1.5)14.6 (1.8)0.06
Number of live births2.0 (1.0)2.1 (0.9)1.9 (1.0)0.15
Age at first live birth (y)b25.4 (4.8)25.3 (4.7)25.6 (5.2)0.74
Diet
 Mean (SD) amount per day
  Energy (kcals)1,478 (366)1,481 (376)1,472 (348)0.87
  Energy from fat (%)25.1 (5.7)24.8 (5.6)25.8 (5.8)0.19
  Fiber (g)13.7 (4.7)13.7 (4.7)13.8 (4.7)0.93
  Isoflavones (mg)10.4 (16.5)10.6 (16.6)9.9 (16.4)0.75
 Mean (SD) servings/wk
  Red meat11.8 (9.6)11.7 (9.8)11.9 (9.3)0.87
  Dairy4.1 (5.0)4.0 (5.0)4.4 (5.1)0.61
  Fruit10.1 (7.3)10.7 (7.3)8.9 (7.3)0.08
  Vegetables25.0 (11.6)25.3 (12.9)24.3 (8.6)0.54
  Tofu4.8 (9.1)4.7 (8.4)4.8 (10.5)0.98
%
Education0.14
 ≤8 y535648
 9–12 y/technical school343533
 At least some college13919
Speak English at home0.53
 Not at all727272
 A little202117
 Somewhat, much, or very much8711
First or second degree relative with breast cancer0.90.71.30.62
Perimenopausal stageb0.35
 Premenopausal696969
 Early perimenopausal151612
 Late perimenopausal674
 Postmenopausal10815
Total duration of breastfeeding0.40
 None201923
 ≤1 y424240
 >1–2 y262921
 >2 y121016
Ever used oral contraceptives1211130.57
Ever used female hormones1.82.01.30.72

NOTE: Correlates of equol-producing status in sample of Chinese immigrant women (n = 224).

  • aP comparing equol producers and nonproducers using t tests for continuous variables and χ2 test statistics for categorical variables.

  • bBecause of missing values, sample size was n = 223 for BMI, n = 217 for age at first live birth, and n = 221 for perimenopausal stage.