Intake of dietary folate vitamers and risk of colorectal carcinoma: results from The Netherlands Cohort Study.
BACKGROUND
Several studies have reported inverse associations between folate intake and colorectal carcinoma risk. Few were prospective studies and none evaluated the association between the intake of individual folate vitamers and colorectal carcinoma risk.


METHODS
The aim of the current study was to investigate the relationship between dietary folate intake and the risk of colorectal carcinoma in a large prospective cohort study in The Netherlands comprising 120,852 men and women aged 55-69 years. After 7.3 years of follow-up, 760 colon and 411 rectal carcinoma cases were available for analysis. Data processing and analysis used the case-cohort approach. A new Dutch database was used to estimate intakes of total and individual folate vitamers.


RESULTS
Analyses adjusted for age, energy intake, family history of colorectal carcinoma, alcohol, vitamin C, iron, and dietary fiber intake yielded an inverse association between colon carcinoma risk and total dietary folate intake (rate ratio [RR]highest vs. lowest quintile, men: 0.73; 95% confidence interval [CI], 0.46-1.17, P trend = 0.03; women: 0.68; 95% CI, 0.39-1.20, P trend = 0.18). An inverse association between rectal carcinoma and total dietary folate intake was found only among men (RR highest vs. lowest quintile, men: 0.66; 95% CI, 0.35-1.21, P trend = 0.03). Analyses showed no clear difference in colorectal carcinoma risk associated with intake of different folate vitamers.


CONCLUSIONS
Dietary folate intake was related inversely to colon and male rectal carcinoma risk.
Konings
Erik J M
EJ
Inspectorate for Health Protection and Veterinary Public Health, 's-Hertogenbosch, The Netherlands. Erik.Konings@kvw.nl
Goldbohm
R Alexandra
RA
Brants
Henny A M
HA
Saris
Wim H M
WH
van den Brandt
Piet A
PA
D000368:Aged; D015331:Cohort Studies; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D004032:Diet; D005260:Female; D005492:Folic Acid / Q000494:pharmacology*; D006397:Hematinics / Q000494:pharmacology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D012004:Rectal Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D012307:Risk Factors; D012737:Sex Factors
D006397:Hematinics; D005492:Folic Acid