Folate status and incident cancer morbidity among adults in the U.S. (628.6)

Folate and cancer incidence among adults in the U.S. Jing Hu, Wenyen Juan, Ph.D. and Nadine R. Sahyoun, Ph.D., R.D. Folic acid fortification of grain products in the U.S. has significantly improved population folate status and decreased incidence of Neural Tube Defects. Recently, concerns were raised that excessive folic acid intake may increase cancer risk. We tested the association between folate status and cancer incidence in post‐fortification years among NHANES 1999‐2002 participants aged 57 and over. Cancer incidence was obtained from Medicare files with 5‐8 years follow up. Cox proportional hazards modeling was used to examine the relationship between serum and RBC folate, folic acid and dietary folate equivalents (DFEs) and risk of overall cancer incidence. Over 8100 person‐years of follow‐up, 144 cancer cases were documented. Results showed that participants in the highest quartile for RBC folate (>=421.00 ng/ml) or DFE (>=818.6 µg), were at lower risk of cancer incidence. The Hazard Ratios adjusted for confounders of the highest quartile versus the second quartile of RBC folate and DFEs were 0.545 [0.312‐0.953] and 0.535 [0.300‐0.954], respectively. There were no significant associations between serum folate, folic acid intake and incident cancer. Our findings suggest a protective effect of RBC folate and DFEs against cancer. The post‐fortification consumption of folic acid in an older population did not appear to increase overall cancer risk.