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- Kim, Dong-Hyun, et al.
(författare)
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Pooled analyses of 13 prospective cohort studies on folate intake and colon cancer
- 2010
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Ingår i: Cancer Causes and Control. - : SPRINGER. - 0957-5243 .- 1573-7225. ; 21:11, s. 1919-1930
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Tidskriftsartikel (refereegranskat)abstract
- Studies of folate intake and colorectal cancer risk have been inconsistent. We examined the relation with colon cancer risk in a series of 13 prospective studies. Study- and sex-specific relative risks (RRs) were estimated from the primary data using Cox proportional hazards models and then pooled using a random-effects model. Among 725,134 participants, 5,720 incident colon cancers were diagnosed during follow-up. The pooled multivariate RRs (95% confidence interval [CI]) comparing the highest vs. lowest quintile of intake were 0.92 (95% CI 0.84-1.00, p-value, test for between-studies heterogeneity = 0.85) for dietary folate and 0.85 (95% CI 0.77-0.95, p-value, test for between-studies heterogeneity = 0.42) for total folate. Results for total folate intake were similar in analyses using absolute intake cutpoints (pooled multivariate RR = 0.87, 95% CI 0.78-0.98, comparing a parts per thousand yen560 mcg/days vs. < 240 mcg/days, p-value, test for trend = 0.009). When analyzed as a continuous variable, a 2% risk reduction (95% CI 0-3%) was estimated for every 100 mu g/day increase in total folate intake. These data support the hypothesis that higher folate intake is modestly associated with reduced risk of colon cancer.
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2. |
- Park, Yikyung, et al.
(författare)
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Intakes of vitamins A, C, and E and use of multiple vitamin supplements and risk of colon cancer : a pooled analysis of prospective cohort studies
- 2010
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Ingår i: Cancer Causes and Control. - : Springer Science and Business Media LLC. - 0957-5243 .- 1573-7225. ; 21:11, s. 1745-1757
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the associations between intakes of vitamins A, C, and E and risk of colon cancer. Using the primary data from 13 cohort studies, we estimated study- and sex-specific relative risks (RR) with Cox proportional hazards models and subsequently pooled RRs using a random effects model. Among 676,141 men and women, 5,454 colon cancer cases were identified (7-20 years of follow-up across studies). Vitamin A, C, and E intakes from food only were not associated with colon cancer risk. For intakes from food and supplements (total), the pooled multivariate RRs (95% CI) were 0.88 (0.76-1.02, > 4,000 vs. a parts per thousand currency sign1,000 mu g/day) for vitamin A, 0.81 (0.71-0.92, > 600 vs. a parts per thousand currency sign100 mg/day) for vitamin C, and 0.78 (0.66-0.92, > 200 vs. a parts per thousand currency sign6 mg/day) for vitamin E. Adjustment for total folate intake attenuated these associations, but the inverse associations with vitamins C and E remained significant. Multivitamin use was significantly inversely associated with colon cancer risk (RR = 0.88, 95% CI: 0.81-0.96). Modest inverse associations with vitamin C and E intakes may be due to high correlations with folate intake, which had a similar inverse association with colon cancer. An inverse association with multivitamin use, a major source of folate and other vitamins, deserves further study.
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