Table 4.

Associations of colorectal cancer risk with use of various herbal and specialty supplements during the previous 10 y, the VITAL Study (n = 76,512)

Herbal or specialty supplement*Colorectal cancer cases (n = 428), n (%)Noncolorectal cancer cases (n = 76,084), n (%)Adjusted hazard ratio (adjusted 95% CI)
Fish oil
    No use399 (93)68,417 (90)1.00 (Reference)
    Any pills per day during the previous 10 y28 (7)7,424 (10)0.65 (0.42-0.99)
    User vs non-user P0.05
Garlic pills
    No use358 (84)66,893 (88)1.00 (Reference)
    Any pills per day during the previous 10 y70 (16)8,883 (12)1.35 (1.01-1.81)
    User vs non-user P0.04
Gingko biloba
    No use377 (88)65,146 (86)1.00 (Reference)
    Any pills per day during the previous 10 y49 (12)10,373 (14)0.83 (0.59-1.17)
    User vs non-user P0.29
Ginseng
    No use397 (93)69,528 (92)1.00 (Reference)
    Any pills per day during the previous 10 y29 (7)6,309 (8)0.86 (0.56-1.33)
    User vs non-user P0.50
Grapeseed
    No use406 (95)70,177 (92)1.00 (Reference)
    Any pills per day during the previous 10 y22 (5)5,746 (8)0.72 (0.44-1.18)
    User vs non-user P0.19
Glucosamine
    No use360 (85)60,444 (80)1.00 (Reference)
    Any pills per day during the previous 10 y66 (15)15,373 (20)0.73 (0.54-0.98)
    User vs non-user P0.03
Chondroitin
    No use385 (90)65,556 (86)1.00 (Reference)
    Any pills per day during the previous 10 y42 (10)10,316 (14)0.65 (0.45-0.93)
    User vs non-user P0.02
Melatonin
    No use410 (96)72,080 (95)1.00 (Reference)
    Any pills per day during the previous 10 y15 (4)3,794 (5)0.58 (0.30-1.13)
    User vs non-user P0.11
MSM
    No use415 (97)72,262 (95)1.00 (Reference)
    Any pills per day during the previous 10 y13 (3)3,678 (5)0.46 (0.23-0.93)
    User vs non-user P0.03
St. John's wort
    No use418 (98)72,000 (95)1.00 (Reference)
    Any pills per day during the previous 10 y8 (2)3,866 (5)0.35 (0.14-0.85)
    User vs non-user P0.02
Saw palmetto§
    No use194 (88)32,424 (89)1.00 (Reference)
    Any pills per day during the previous 10 y26 (12)4,017 (11)1.01 (0.65-1.58)
    User vs non-user P0.97
  • NOTE: Only herbal or specialty supplements for which at least 5% of either cases or noncases were users are included. Numbers may not sum to the total and percentages may not add up to 100% because of missing data and/or rounding.

  • * Based on self-reported intakes from the individual supplements, mixtures, and multivitamins, when relevant.

  • Adjusted for age, gender, education, physical activity, fruit and vegetable consumption, BMI, NSAID use, and sigmoidoscopy.

  • Adjusted for age, gender, education, physical activity, fruit and vegetable consumption, BMI, NSAID use, sigmoidoscopy, and history of arthritis. Also, glucosamine, chondroitin, and MSM were adjusted for each of the other two supplements.

  • § Saw palmetto was asked of men only.