Am J Clin Nutr. 2013 Feb;97(2):332-43.
B vitamin intakes and incidence of colorectal cancer: results from the Women's Health Initiative Observational Study cohort.
Zschäbitz S, Cheng TY, Neuhouser ML, Zheng Y, Ray RM, Miller JW, Song X, Maneval DR, Beresford SA, Lane D, Shikany JM, Ulrich CM.
Source
Division of Preventive Oncology, National Center for Tumor Diseases, Heidelberg,
Germany.
Abstract
BACKGROUND:
The role of one-carbon metabolism nutrients in colorectal carcinogenesis is not
fully understood. Associations might be modified by mandated folic acid (FA)
fortification or alcohol intake.
OBJECTIVE:
We investigated associations between intakes of folate, riboflavin, vitamin B-6,
and vitamin B-12 and colorectal cancer (CRC) in the Women's Health Initiative
Observational Study, stratified by time exposed to FA fortification and alcohol
intake.
DESIGN:
A total of 88,045 postmenopausal women were recruited during 1993-1998; 1003
incident CRC cases were ascertained as of 2009. Quartiles of dietary intakes
were compared; HRs and 95% CIs were estimated by Cox proportional hazards models.
RESULTS:
Dietary and total intakes of vitamin B-6 in quartile 4 compared with quartile 1
(HR: 0.80; 95% CI: 0.66, 0.97 and HR: 0.80; 95% CI: 0.66, 0.99, respectively)
and total intakes of riboflavin (HR: 0.81; 95% CI: 0.66, 0.99) were associated
with reduced risk of CRC overall and of regionally spread disease. In current
drinkers who consumed <1 drink (13 g alcohol)/wk, B vitamin intakes were
inversely associated with CRC risk (P-interaction < 0.05). Dietary folate intake
was positively associated with CRC risk among women who had experienced the
initiation of FA fortification for 3 to <9 y (P-interaction < 0.01).
CONCLUSIONS:
Vitamin B-6 and riboflavin intakes from diet and supplements were associated
with a decreased risk of CRC in postmenopausal women. Associations of B vitamin
intake were particularly strong for regional disease and among women drinkers
who consumed alcohol infrequently. Our study provides new evidence that the
increased folate intake during the early postfortification period may have been
associated with a transient increase in CRC risk.
PMID: 23255571 [PubMed - indexed for MEDLINE]