Dietary factors of one-carbon metabolism in relation to non-Hodgkin lymphoma and multiple myeloma in a cohort of male smokers

Reported associations between genetic polymorphisms in folate-metabolizing enzymes and lymphoid malignancies suggest etiologic involvement of one-carbon metabolism and its related dietary exposures. We examined dietary factors of one-carbon metabolism in relation to non-Hodgkin lymphoma WHO and multiple myeloma (MM) among 27,111 healthy male smokers who completed baseline dietary questionnaires in the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study cohort. During a follow-up of up to 16.4 years (19852001), 195 NHL and 32 MM cases were ascertained. Cox proportional hazard models were used to estimate multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (95% CI). There was no significant association between dietary folate and NHL (HR comparing fourth to first quartile, 1.03; 95% CI, 0.68-1.55). Dietary vitamin B-12 was inversely associated with NHL (HR, 0.61; 95% CI, 0.37-1.00; P-trend = 0.06). The inverse association of vitamin B-12 was evident for diffuse subtype but did not reach statistical significance. There were no significant associations of dietary vitamin B-6 Or B-2, methionine, or alcohol with NHL. None of the dietary or supplemental one-carbon nutrients were associated with MM, although the power of these analyses was limited. Our results suggest that high intake of vitamin B-12 among heavy smokers may be protective against NHL but warrant further studies, including among nonsmokers.