Vegetables and distal colon cancer.
Total vegetables and distal colon cancer risk.
Data about the relation between total vegetables and distal colon cancer risk was provided by a pooled analysis of 14 cohorts, and two additional
cohorts, which were both of very large size.
A significant protective effect was found in the pooled analysis (Koushik A [29]) including 756,217 subjects: RR = 0.82 (0.68-0.98; P = 0.01). Stratified by sex, the strength of
the associaton did not change, but the trend became nonsignificant among both men and women. A significant protective effect among men, but not women was found in another
cohort (Park Y [27]). No association was found in the remaining cohort (van Duijnhoven FJ [18]).
The average RR = 0.83 (excluding incomplete data from Park Y [27]).
Inclusion of intermediate levels of consumption:
Among men, a strong significant protective effect was found at the level of 200- < 300 g/day in the pooled analysis (Koushik A [29]). In addition, significant protective
effects were found at 2 different levels of consumption (median 270, and median 540 g/day) in a cohort of very large size (Park Y).
Among women, also a significant protective effect was found at the consumption level of 200- < 300 g/day in the pooled analysis, but in the remainig cohort,
no associations were found at any level of consumption.
Conclusion: A significant protective effect of high vs low consumption (≥ 200 g/day) was found in a pooled analysis, but the trend became nonsignificant when
stratified by sex. In addition, a significant protective effect of high vs low consumption was also found in cohort of very large size, but this effect was restricted to
men only. High vs low vegetable consumption possibly protects against distal colon cancer risk among both sexes.
A significant protective effect of an intermediate level of consumption (200-< 300 g/day) was found among both men and women, which remained significant when
stratified by sex. Among men, this effect was strengthened by results from one cohort of very large size, in which a significant protective effect was found at this level
of consumption. Total vegetables probably protect against distal colon cancer risk among men at the level of 200-< 300 g/day.
| Author | Cohort name | Cases | Relative Risk (RR) |
|---|---|---|---|
| 29) Koushik A (2007) | Pooled analysis of 14 cohorts. | 810 men, and 1,431 women | Men: RR = 0.83 (0.61-1.15; P = 0.10). Women: RR = 0.81 (0.65-1.02; P = 0.06). |
| 27) Park Y (2007) | The NIH-AARP Diet and Health Study | Not defined. | Men: RR = 0.76 (0.59-0.98; P = 0.04). Women: RR = 1.15 (0.76-1.73; P = 0.42). |
| 18) van Duijnhoven FJ (2009) | The EPIC Study | 790 | HR = 0.86 (0.66-1.14; P = 0.24). |
| Total number of cases: 3,031 + X | Average RR = 0.83 |
| Author | Cohort name | Subjects | Years of follow-up | Cases | End point | Consumption of | Relative Risk (RR) | Adjustments | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 29) Koushik A. (2007) | Pooled Analysis of 14 Cohort Studies. | 756,217 subjects (242,362 men and 513,855 women) | 6-20 years | 2241 (1431 women, 810 men) | Distal colon cancer risk (tumors in the descending and sigmoid colon) | Total vegetables (Vegetables and vegetable juices. Excluding potatoes and mature beans) |
INCLUSION CRITERIA:
INCLUDED STUDIES (Follow-up years/No. of colon cancer cases). In the analysis, an extended follow-up period for most of the studies was included:
RELATIVE RISK:
BMI; height; education; physical activity; family history of colorectal cancer; postmenopausal hormone use; oral contraceptive use; use of nonsteroidal anti-inflammatory drugs; multivitamin use; smoking habits (never/past/current + amount); red meat; total milk; alcohol; and total energy. Age in years and year of questionnaire return were included as stratification variables. |
27) Park Y. (2007) | The NIH-AARP Diet And Health Study. | 488,043 (291,094 men and 196,949 women) aged 50-71. | (USA) 4,3 | (1996-2000) No data shown. | (2,972 for total colorectal cancer risk ([2,048 men and 924 women]) Distal colon cancer risk | Vegetables (Not defined. Excluding potatoes except sweet potatoes) |
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One serving = 1 cup of leafy vegetables, 1/2 cup of other vegetables, or 6 ounces of juice (1 cup = 237 mL, 1 ounce = 29.6 mL). education, physical activity, smoking (smoking/past/current. And < or = 20 vs > 20 cigarettes/day), alcohol, red meat, dietary calcium, total energy. |
Additional adjustment for race; BMI; family history of colorectal cancer; colorectal cancer screening; use of multivitamins, NSAID's, and menopausal hormone therapy in women; and vitamin D intake showed similar results. Mutual adjustment for intakes of fruits and vegetables did not change the results. Adjustment for dietary fiber did not change the results. 18) van Duijnhoven FJ (2009) | The EPIC Study | 452,755 subjects (131,985 men and 320,770 women) from 10 European countries. | 8.7-8.8 | (1992-2000 to 2006) 790 | Distal colon cancer incidence | (including the descending and sigmoid colon) All vegetables (leafy vegetables, fruiting vegetables, root vegetables, cabbages, onions and garlic, mushrooms, grain and pod vegetables [e.g. peas], stalk vegetables and sprouts, mixed salads/mixed vegetables, and unclassified vegetables. | excluding legumes or potatoes and other tubers)
HR = 0.86 (0.66-1.14; P = 0.24) for the highest vs lowest quintile of consumption. | Effect modification: Tertiles of red and processed meat or alcohol did not modify the association between vegetable consumption and the risk of cancer (no data shown). BMI modified the association: an inverse association was most apparent in the highest tertile of BMI (no data shown). Stratified by age at entry, sex, and center. Adjusted for energy from fat, energy from nonfat, weight, height, physical activity, smoking status, alcohol consumption, red and processed meat consumption, fish consumption, dietary fiber from cereal sources, and consumption of fruit. |
15) Terry P (2001) | The Swedish Mammography Screening Cohort. | 61,463 women aged 40-74. | 9.6 | (1987-90 to 1998) 101 | Distal colon cancer risk | Vegetables (such as cabbage, tomatoes, lettuce, spinach, potatoes, and carrots and beets) |
RR = 1.13 (0.66-1.94; P = 0.85) for the highest vs lowest quartile of consumption. | Amount specific data (servings/day): < 1.0: RR = 1. 1.0-1.5: RR = 1.28 (0.76-2.17). 1.5-2.0: RR = 0.70 (0.38-1.29). > 2.0: RR = 1.13 (0.66-1.94). Age, consumption of red meat and dairy products, and total calories. |
9) Voorrips LE. (2000) | The Netherlands Cohort Study. | 62,573 women and 58,279 men aged 55-69. | (The Netherlands) 6.3 | (1986-1992) 153 men, 116 women | Distal colon cancer risk | Total vegetables (Brussels sprouts, cauliflower, cabbage, spinach, cooked endive, beetroot, string beans, broad beans, kale, cooked carrots, sweet peppers, sauerkraut, rhubarb, mushrooms, gherkins, raw endive, raw carrots, lettuce, tomatoes) |
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Age, family history of colorectal cancer, and alcohol. Total energy intake, smoking, physical activity, and BMI were evaluated as potential confounders. |
8) Steinmetz KA. (1994) | The Iowa Women's Health Study. | 35,216 women aged 55-69. | (USA) 5 | (1986-1990) 120 | Distal colon cancer risk | Vegetables (alfalfa sprouts, artichokes, asparagus, avocado, bean sprouts, beets, broccoli, Brussels sprouts, cabbage/coleslaw, carrots, cauliflower, celery, chicory, corn, daikon radish, eggplant/zucchini/other summer squash, endive, escarole, garlic, green/chili peppers, iceberg/head lettuce, Jerusalem artichokes, kale/mustard/chard greens, kohlrabi, leeks, mixed vegetables, mushrooms, okra, oriental vegetables, parsley, parsnips, peapods, peas/lima beans, potatoes, radishes, rhubarb, romaine/leaf lettuce, rutabagas, scallions, spinach, string beans, tomatoes, tomato sauce, turnips, water chestnuts, yams, and yellow squash) |
RR = 0.62 (0.35-1.09) for the highest vs lowest quartile of consumption. | Amount specific data (servings/week): < 15.1: RR = 1. 15.1-21.5: RR = 0.62 (0.36-1.05). 21.6-30.4: RR = 1.08 (0.67-1.73). > 30.4: RR = 0.62 (0.35-1.09). 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 | 112? men, 68? women | Distal colon cancer risk (descending to sigmoid colon) | Vegetables (defined as: beans, such as baked beans, limas, pintos, kidney, or in chili. Tomatoes, tomato juice. Broccoli. Spinach. Mustard greens, turnip greens, colards. Coleslaw, cabbage, sauerkraut. Carrots, or mixed vegetables containing carrots. Green salad. Sweet potatoes, yams. Any other vegetable, including green beans, corn, peas. Spaghetti, lasagna and other pasta with tomato sauce. Vegetable soup) |
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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. |
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