Table 1.

Selected baseline characteristics of participants (n = 47)

Characteristics*Placebo (n = 23)Antioxidants (n = 24)P
Demographics
    Age (y), median (range)59 (36-71)61 (41-73)0.55
    Sex (% males)52.250.00.88
    Race (% white)91.387.5>0.99
    Education (% attended college)21.726.1>0.99
Medical history
    First-degree relative with CRC (%)21.726.1>0.99
    Take NSAID regularly (%)13.020.80.70
    Currently smoke (%)45.039.00.76
    Alcohol intake (g/d), median (range)0 (0-31.5)0.25 (0-42)0.46
    Postmenopausal, n = 23 (%)45.550.0>0.99
Anthropometrics
BMI (kg/m2), median (range)
        Men25.1 (19.0-30.2)27.2 (23.1-30.7)0.11
        Women29.5 (16.6-41.0)26.7 (18.5-65.8)0.16
    Waist-to-hip ratio
        Men0.99 (0.10)1.01 (0.05)0.55
        Women0.84 (0.11)0.85 (0.07)0.96
Colorectal adenoma history
    No. adenomas removed, median (range)2 (1-6)2 (1-11)0.65
    Size of largest adenoma removed (cm), median (range)0.5 (0.2-3.0)0.65 (0.2-2.5)0.29
    Villous/tubulovillous adenoma (%)8.712.5>0.99
Mean dietary intakes
Total energy intake (kcal/d)
        Males2,133 (193)1,685 (193)0.11
        Females1,351 (152)1,750 (145)0.07
    Total α-tocopherol (mg/d)§7.9 (0.7)7.4 (0.7)0.60
    Total vitamin C (mg/d)§90 (14)141 (13)0.01
    Total β-carotene (μg/d)§3,418 (405)3,813 (388)0.49
    Total riboflavin (mg/d)§1.6 (0.1)1.7 (0.1)0.53
    Total niacin (mg/d)§22 (1.6)20 (1.5)0.39
    Total zinc (mg/d)§11 (0.9)10 (0.9)0.59
    Total manganese (mg/d)§2.7 (0.3)2.7 (0.3)0.93
    Total iron (mg/d)§12.2 (1.3)11.9 (1.3)0.88
    Red meat (servings/wk)4.7 (3.3)3.1 (2.7)0.09
    Total fruits/vegetables (servings/wk)36 (16.4)40.5 (19.1)0.41
Plasma antioxidant levels
    β-Carotene (μg/mL), median (range)0.09 (0.01-0.17)0.08 (0.02-0.51)>0.99
    α-Tocopherol (μg/mL), median (range)9.4 (6.0-13.7)9.1 (5.7-15.0)0.67

Abbreviations: CRC, colorectal cancer; NSAID, nonsteroidal anti-inflammatory drug; BMI, body mass index.

  • *Data are given as means (SD) unless otherwise specified.

  • P values based on χ2 test for categorical variables, t test of means, or Wilcoxon test for medians.

  • At least once a week.

  • §Total = dietary + supplemental.