| 8) Sellers TA (1998) | The Iowa Women's Health Study. | 35,216 women aged 55-69 years.
(USA) | 10
(1986-1995) | 241
(180 without, 61 with a family history of colon cancer) | colon cancer risk | Fruit and vegetables high in vitamin C |
Stratified on family history of colon cancer:
| No family history | Positive family history |
RR = 0.9 (0.6-1.3; P = 0.6) for the highest vs lowest tertile of consumption.
Amount specific data (servings/wk):
< 5.5: RR = 1.
5.6-10: RR = 0.9 (0.6-1.2).
> 10: RR = 0.9 (0.6-1.3).
|
RR = 1.0 (0.5-1.8; P = 0.9) for the highest vs lowest tertile of consumption.
Amount specific data (servings/wk):
< 5.5: RR = 1.
5.6-10: RR = 0.8 (0.4-1.5).
> 10: RR = 1.0 (0.5-1.8).
|
age, total energy, and history of rectal colon polyps. |
| 8) Steinmetz KA. (1994) | The Iowa Women's Health Study. | 35,216 women aged 55-69.
(USA) | 5
(1986-1990) | 212? | Colon cancer risk | Vegetables and fruit high in vitamin C (Broccoli, cantaloupe, dried currants, grapefruit, grapefruit juice, green/chili peppers, guavas, honeydew melon, kiwi fruit, kohlrabi, mangoes, orange juice, oranges, other fruit juice, strawberries, v-8 juice) |
RR = 0.99 (0.68-1.46) for the highest vs lowest quartile of consumption.
Amount specific data (servings/week):
< 6.5: RR = 1.
6.5-10.0: RR = 0.95 (0.66-1.37).
10.1-14.0: RR = 0.76 (0.50-1.14).
> 14.0: RR = 0.99 (0.68-1.46). | Age, energy. The effect of adjustment of the vegetable and fruit associations for the following factors was negligible: BMI, parity, age at first live birth, physical activity, smoking, education, history of polyps or colitis, and alcohol intake. |
| 7) McCullough ML (2003) | The Cancer Prevention Study II Nutrition Cohort. | 62,609 men and 70,554 women aged 50-74. (The Nutrition Cohort is a subgroup of the approx. 1.2 million participants in CPS II) | 1992-93 to 1997 | 508 (298 men, 210 women) | colon cancer risk (fatal and nonfatal) | High vitamin C foods (>50 mg/100 g) (defined as: Oranges, Orange juice. Broccoli) |
| Men: | Women: |
RR = 0.69 (0.48-1.01; P = 0.65) for the highest vs lowest quintile of consumption.
Amount specific data (servings/day):
< 0.3: RR = 1.
0.3-< 0.9: RR = 0.76 (0.52-1.10).
0.9-< 2.1: RR = 0.80 (0.56-1.14).
2.1-< 4.6: RR = 1.22 (0.88-1.70).
≥ 4.6: RR = 0.69 (0.48-1.01).
|
RR = 0.79 (0.52-1.21; P = 0.46) for the highest vs lowest quintile of consumption.
Amount specific data (servings/day):
< 0.3: RR = 1.
0.3-< 0.9: RR = 0.84 (0.56-1.27).
0.9-< 1.8: RR = 0.60 (0.38-0.94).
1.8-< 4.6: RR = 0.85 (0.56-1.29).
≥ 4.6: RR = 0.79 (0.52-1.21).
|
age, exercise, METs, aspirin, smoking, family history of colorectal cancer, BMI, education, energy, multivitamin use, total calcium and red meat intake. Alcohol intake was not included because it did not influence the effect estimates when entered in the multivariate models. |
| 6) Michels KB. (2000) | The Nurses' Health Study
&
The Health Professionals' Follow-up Study. | 88,764 women aged 34-59 and 47,325 men aged 40-75.
(USA) | Women: 16
(1980-1996).
Men: 10
(1986-1996) | Colon cancer: 937 (368 men, 569 women).
Rectal cancer: 244 (89 men, 155 women). | Colorectal cancer risk | A vitamin C rich vegetable or fruit was used in the definition if it was included in at least 2 (out of 4) different FFQs of the NHS.
Fruits and vegetables rich in vitamin C
(defined as: broccoli, Brussels sprouts, cantaloupe, grapefruit, oranges, strawberries, grapefruit juice, orange juice, other fruit juices) |
Colon cancer risk:
| Women | Men |
RR = 0.78 (No 95% CI; No P-value) for the highest vs lowest quintile of consumption
Amount specific data (servings):
≤ 1/wk: RR = 1.
2-4/wk: RR = 0.85.
5-6/wk: RR = 0.72.
1/day: RR = 0.77.
≥ 2/day: RR = 0.78.
|
RR = 1.18 (No 95% CI; No P-value) for the highest vs lowest quintile of consumption
Amount specific data (servings):
≤ 1/wk: RR = 1.
2-4/wk: RR = 1.02.
5-6/wk: RR = 0.70.
1/day: RR = 1.16.
≥ 2/day: RR = 1.18.
|
men + women combined (colon cancer):
| No vitamin supplement users | Vitamin supplement users |
| RR = 1.00 (0.88-1.15) for 1 additional serving/day. | RR = 1.04 (0.95-1.13) for 1 additional serving/day. |
men + women combined (colon cancer):
| Never smokers | Ever smokers |
| RR = 0.98 (0.87-1.11) for 1 additional serving/day. | RR = 1.06 (0.96-1.17) for 1 additional serving/day. |
Rectal cancer risk:
| Women | Men |
RR = 0.63 (No 95% CI; No P-value) for the highest vs lowest quintile of consumption
Amount specific data (servings):
≤ 1/wk: RR = 1.
2-4/wk: RR = 1.16.
5-6/wk: RR = 0.52.
1/day: RR = 0.83.
≥ 2/day: RR = 0.63.
|
RR = 2.52 (No 95% CI; No P-value) for the highest vs lowest quintile of consumption
Amount specific data (servings):
≤ 1/wk: RR = 1.
2-4/wk: RR = 2.81.
5-6/wk: RR = 2.51.
1/day: RR = 2.87.
≥ 2/day: RR = 2.52.
|
age, family history of colorectal cancer, sigmoidoscopy, height, body mass index, pack-years of smoking, alcohol intake, physical activity, (women: menopausal status, postmenopausal hormone use,) aspirin use, vitamin supplement intake (ever use of multivitamins or vitamins A, C, or E), total caloric intake, and red meat consumption. |
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