Folate and other methyl-group nutrients may play a key role in pancreatic carcinogenesis through their effects on DNA integrity. We examined the association between pancreatic cancer and intake of folate, vitamins B6, B12 and methionine in a large population-based case–control study.
Risk factor data were collected during in-person interviews with 532 pancreatic cancer cases diagnosed in 1995–1999 and 1,701 frequency-matched controls in the San Francisco Bay Area. Dietary history and supplement use were obtained using a semi-quantitative food-frequency questionnaire developed at Harvard University. Adjusted unconditional logistic regression was used to compute odds ratios (OR) and 95% confidence intervals (CI) as estimates of the relative risk.
Total folate intake was inversely associated with pancreatic cancer (5th vs. 1st quintile: OR = 0.67, 95% CI = 0.48–0.93, p trend = 0.04). Increased vitamin B12 from food was positively associated with pancreatic cancer although risk estimates for quintiles 3–5 were similar (5th vs. 1st quintile: OR = 1.9, 95% CI = 1.3–2.6, p trend = 0.001). Intake of vitamin B6 or methionine was not associated with pancreatic cancer risk.
Our study provided some support for an inverse association between folate intake and pancreatic cancer risk. The increased pancreatic cancer risk with vitamin B12 intake from food warrants further investigation.