title: Pooled analyses of 13 prospective cohort studies on folate intake and colon cancer.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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 ≥ 560 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 μg/day increase in total folate intake.
  
  
  CONCLUSIONS
  These data support the hypothesis that higher folate intake is modestly associated with reduced risk of colon cancer.
authors.affiliation: Department of Social and Preventive Medicine, College of Medicine, Hallym University, Chunchon, Korea.
authors.forename: Dong-Hyun
authors.initials: DH
authors.lastname: Kim
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Smith-Warner
authors.forename: Donna
authors.initials: D
authors.lastname: Spiegelman
authors.forename: Shiaw-Shyuan
authors.initials: SS
authors.lastname: Yaun
authors.forename: Graham A
authors.initials: GA
authors.lastname: Colditz
authors.forename: Jo L
authors.initials: JL
authors.lastname: Freudenheim
authors.forename: Edward
authors.initials: E
authors.lastname: Giovannucci
authors.forename: R Alexandra
authors.initials: RA
authors.lastname: Goldbohm
authors.forename: Saxon
authors.initials: S
authors.lastname: Graham
authors.forename: Lisa
authors.initials: L
authors.lastname: Harnack
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Jacobs
authors.forename: Michael
authors.initials: M
authors.lastname: Leitzmann
authors.forename: Satu
authors.initials: S
authors.lastname: Mannisto
authors.forename: Anthony B
authors.initials: AB
authors.lastname: Miller
authors.forename: John D
authors.initials: JD
authors.lastname: Potter
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Rohan
authors.forename: Arthur
authors.initials: A
authors.lastname: Schatzkin
authors.forename: Frank E
authors.initials: FE
authors.lastname: Speizer
authors.forename: Victoria L
authors.initials: VL
authors.lastname: Stevens
authors.forename: Rachael
authors.initials: R
authors.lastname: Stolzenberg-Solomon
authors.forename: Paul
authors.initials: P
authors.lastname: Terry
authors.forename: Paolo
authors.initials: P
authors.lastname: Toniolo
authors.forename: Matty P
authors.initials: MP
authors.lastname: Weijenberg
authors.forename: Walter C
authors.initials: WC
authors.lastname: Willett
authors.forename: Alicja
authors.initials: A
authors.lastname: Wolk
authors.forename: Anne
authors.initials: A
authors.lastname: Zeleniuch-Jacquotte
authors.forename: David J
authors.initials: DJ
authors.lastname: Hunter
mesh_terms: D015331:Cohort Studies; D003110:Colonic Neoplasms / Q000517:prevention & control*; D015179:Colorectal Neoplasms / Q000517:prevention & control*; D016001:Confidence Intervals; D004032:Diet; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage*; D006801:Humans; D015994:Incidence; D008297:Male; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012306:Risk
chemical_list: D005492:Folic Acid
references.citation: Ann Intern Med. 2004 Apr 20;140(8):603-13
references.pmid: 15096331
references.citation: JAMA. 2007 Jun 6;297(21):2408-9
references.pmid: 17551134
references.citation: Ann Epidemiol. 1994 May;4(3):181-7
references.pmid: 8055118
references.citation: Carcinogenesis. 1989 Jul;10(7):1209-14
references.pmid: 2472230
references.citation: Br J Cancer. 1999 Apr;79(11-12):1917-22
references.pmid: 10206314
references.citation: Cancer Epidemiol Biomarkers Prev. 2005 Mar;14(3):740-3
references.pmid: 15767361
references.citation: Am J Epidemiol. 1986 Jul;124(1):17-27
references.pmid: 3521261
references.citation: Am J Clin Nutr. 1989 Sep;50(3):508-16
references.pmid: 2773830
references.citation: Int J Cancer. 2005 Feb 20;113(5):825-8
references.pmid: 15499620
references.citation: Control Clin Trials. 1986 Sep;7(3):177-88
references.pmid: 3802833
references.citation: Eur J Cancer. 2000 Oct;36(16):2115-9
references.pmid: 11044650
references.citation: Am J Epidemiol. 2006 Jan 15;163(2):108-15
references.pmid: 16339055
references.citation: Br J Cancer. 1994 Dec;70(6):1150-5
references.pmid: 7981067
references.citation: Nutr Cancer. 2002;43(2):152-8
references.pmid: 12588695
references.citation: Biochem Biophys Res Commun. 1986 Feb 26;135(1):201-7
references.pmid: 3954771
references.citation: Am J Hematol. 1987 Oct;26(2):199-207
references.pmid: 3310615
references.citation: J Nutr Biochem. 1999 Feb;10(2):66-88
references.pmid: 15539274
references.citation: Cancer Epidemiol Biomarkers Prev. 1997 Oct;6(10):769-74
references.pmid: 9332757
references.citation: Biochem J. 1989 Jan 1;257(1):277-80
references.pmid: 2537625
references.citation: Int J Cancer. 2004 Jan 20;108(3):433-42
references.pmid: 14648711
references.citation: Am J Epidemiol. 1992 Jul 15;136(2):192-200
references.pmid: 1415141
references.citation: Epidemiology. 2000 Jul;11(4):462-8
references.pmid: 10874556
references.citation: Environ Mol Mutagen. 2004;44(1):10-25
references.pmid: 15199543
references.citation: Nutr Cancer. 2002;42(1):10-7
references.pmid: 12235640
references.citation: Am J Epidemiol. 1998 Oct 15;148(8):761-74
references.pmid: 9786231
references.citation: Carcinogenesis. 1997 May;18(5):869-82
references.pmid: 9163670
references.citation: Cancer Causes Control. 2002 Aug;13(6):551-61
references.pmid: 12195645
references.citation: Gastroenterology. 1989 Aug;97(2):255-9
references.pmid: 2568304
references.citation: Cancer Epidemiol Biomarkers Prev. 2007 Jul;16(7):1325-9
references.pmid: 17626997
references.citation: Int J Cancer. 1991 Sep 9;49(2):161-7
references.pmid: 1652565
references.citation: Cancer Epidemiol Biomarkers Prev. 1996 Jul;5(7):487-94
references.pmid: 8827351
references.citation: Biometrics. 1982 Dec;38(4):963-74
references.pmid: 7168798
references.citation: Gastroenterology. 2003 May;124(5):1240-8
references.pmid: 12730865
references.citation: Cancer Causes Control. 2010 Nov;21(11):1745-57
references.pmid: 20820901
references.citation: Int J Cancer. 2002 Feb 20;97(6):864-7
references.pmid: 11857369
references.citation: Adv Exp Med Biol. 1986;206:313-30
references.pmid: 3591525
references.citation: Am J Epidemiol. 2006 Jun 1;163(11):1053-64
references.pmid: 16624970
references.citation: Ann Epidemiol. 2001 Jan;11(1):65-72
references.pmid: 11164122
references.citation: Cancer Res. 1992 Sep 15;52(18):5002-6
references.pmid: 1516055
references.citation: Int J Cancer. 2000 Apr 15;86(2):169-73
references.pmid: 10738242
references.citation: Am J Epidemiol. 2004 Aug 15;160(4):339-49
references.pmid: 15286019
references.citation: Am J Epidemiol. 2003 Oct 1;158(7):621-8
references.pmid: 14507597
references.citation: Proc Natl Acad Sci U S A. 1981 Feb;78(2):917-21
references.pmid: 6940156
references.citation: J Am Diet Assoc. 2000 Jan;100(1):88-94
references.pmid: 10646010
references.citation: Epidemiology. 1996 Mar;7(2):161-5
references.pmid: 8834556
references.citation: Am J Epidemiol. 1988 Feb;127(2):297-309
references.pmid: 3337084
references.citation: Am J Epidemiol. 1985 Jul;122(1):41-50
references.pmid: 4014200
references.citation: Ann Intern Med. 1998 Oct 1;129(7):517-24
references.pmid: 9758570
references.citation: J Natl Cancer Inst. 1993 Jun 2;85(11):875-84
references.pmid: 8492316
references.citation: Am J Clin Nutr. 1977 Dec;30(12):2028-32
references.pmid: 412415
references.citation: Nutr Cancer. 1997;28(1):52-62
references.pmid: 9200151
references.citation: Proc Natl Acad Sci U S A. 1997 Apr 1;94(7):3290-5
references.pmid: 9096386
references.citation: Science. 1985 Apr 12;228(4696):187-90
references.pmid: 2579435
references.citation: Am J Epidemiol. 2004 Mar 1;159(5):423-43
references.pmid: 14977639
references.citation: Nutr Cancer. 1996;26(3):337-46
references.pmid: 8910915
references.citation: Cancer Causes Control. 1997 Nov;8(6):828-40
references.pmid: 9427425
references.citation: Am J Clin Nutr. 1987 Apr;45(4):661-70
references.pmid: 3565292
references.citation: Biometrics. 1996 Jun;52(2):536-44
references.pmid: 8672702
references.citation: Int J Cancer. 2002 Dec 10;102(5):545-7
references.pmid: 12432561
references.citation: J Natl Cancer Inst. 1995 Feb 15;87(4):265-73
references.pmid: 7707417
references.citation: Environ Mol Mutagen. 1989;13(4):319-24
references.pmid: 2737183
references.citation: J Natl Cancer Inst. 1994 Feb 2;86(3):183-91
references.pmid: 8283490
references.citation: Nutr Cancer. 1994;22(2):101-19
references.pmid: 14502840
references.citation: Int J Epidemiol. 1991 Jun;20(2):368-74
references.pmid: 1917236
references.citation: Am J Epidemiol. 1992 May 15;135(10):1114-26; discussion 1127-36
references.pmid: 1632423
references.citation: JAMA. 2007 Jun 6;297(21):2351-9
references.pmid: 17551129
references.citation: Mol Carcinog. 1991;4(3):243-7
references.pmid: 2064728
references.citation: Am J Epidemiol. 1993 Aug 15;138(4):225-36
references.pmid: 8395140
references.citation: Gut. 2002 Aug;51(2):195-9
references.pmid: 12117879
references.citation: Nutr Cancer. 2005;53(1):42-50
references.pmid: 16351505
references.citation: Am J Clin Nutr. 2000 Oct;72(4):998-1003
references.pmid: 11010943
references.citation: J Nutr. 1998 Jul;128(7):1204-12
references.pmid: 9649607
references.citation: Nutr Cancer. 1992;18(2):97-111
references.pmid: 1437657
references.citation: Br Med Bull. 1999;55(3):578-92
references.pmid: 10746348
references.citation: Int J Cancer. 1997 Nov 14;73(4):525-30
references.pmid: 9389567
references.citation: Cancer Causes Control. 2002 Apr;13(3):239-48
references.pmid: 12020105
references.citation: Cancer Epidemiol Biomarkers Prev. 2003 Aug;12(8):747-54
references.pmid: 12917206
references.citation: Cancer. 2002 Oct 1;95(7):1421-33
references.pmid: 12237910