title: Associations between Intake of Folate, Methionine, and Vitamins B-12, B-6 and Prostate Cancer Risk in American Veterans.
abstract: Prostate cancer (PC) is the second leading cause of cancer death in men. Recent reports suggest that excess of nutrients involved in the one-carbon metabolism pathway increases PC risk; however, empirical data are lacking. Veteran American men (272 controls and 144 PC cases) who attended the Durham Veteran American Medical Center between 2004-2009 were enrolled into a case-control study. Intake of folate, vitamin B12, B6, and methionine were measured using a food frequency questionnaire. Regression models were used to evaluate the association among one-carbon cycle nutrients, MTHFR genetic variants, and prostate cancer. Higher dietary methionine intake was associated with PC risk (OR = 2.1; 95%CI 1.1-3.9) The risk was most pronounced in men with Gleason sum <7 (OR = 2.75; 95%CI 1.32- 5.73). The association of higher methionine intake and PC risk was only apparent in men who carried at least one MTHFR A1298C allele (OR = 6.7; 95%CI = 1.6-27.8), compared to MTHFR A1298A noncarrier men (OR = 0.9; 95%CI = 0.24-3.92) (p-interaction = 0.045). There was no evidence for associations between B vitamins (folate, B12, and B6) and PC risk. Our results suggest that carrying the MTHFR A1298C variants modifies the association between high methionine intake and PC risk. Larger studies are required to validate these findings.
authors.affiliation: Department of Obstetrics and Gynecology and Program of Cancer Detection, Prevention and Control, Duke University School of Medicine, Durham, NC 27710, USA.
authors.forename: Adriana C
authors.initials: AC
authors.lastname: Vidal
authors.forename: Delores J
authors.initials: DJ
authors.lastname: Grant
authors.forename: Christina D
authors.initials: CD
authors.lastname: Williams
authors.forename: Elizabeth
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authors.lastname: Masko
authors.forename: Emma H
authors.initials: EH
authors.lastname: Allott
authors.forename: Kathryn
authors.initials: K
authors.lastname: Shuler
authors.forename: Megan
authors.initials: M
authors.lastname: McPhail
authors.forename: Alexis
authors.initials: A
authors.lastname: Gaines
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Calloway
authors.forename: Leah
authors.initials: L
authors.lastname: Gerber
authors.forename: Jen-Tsan
authors.initials: JT
authors.lastname: Chi
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Freedland
authors.forename: Cathrine
authors.initials: C
authors.lastname: Hoyo