SERUM FOLATE AND CHRONIC DISEASE RISK - FINDINGS FROM A COHORT OF UNITED-STATES ADULTS

Background Previous studies have suggested that folate may provide pro tection against various chronic conditions. Methods We examined the ef fect of serum folate concentration on mortality and chronic disease in cidence in a nationally representative sample of 3059 adults of the Na tional Health and Nutrition Examination Survey Epidemiologic Follow-up Study who were first examined from 1971 through 1975 and who were fol lowed for about 19 years through 1992. Proportional hazards regression was used to estimate hazard ratios for the lowest quintile of serum f olate compared with the highest quintile for selected causes of death and disease incidence. Results The hazards ratio for all-cause mortali ty was 1.18 (95% CI: 0.91-1.52); for mortality for diseases of the cir culatory system, 1.31 (95% CI: 0.82-2.12]; and for cancer mortality 0. 99 (95% CI : 0.46-2.11). The hazard ratio for incidence of diseases of the circulatory system was 1.04 (95% CI: 0.86-1.26): and for cancer i ncidence, 1.00 (95% CI: 0.61-1.66). The hazards ratio for all-cause mo rtality was 1.26 (95% C1: 1.01-1.57) for participants with a serum fol ate of <9.3 nmol/l compared with other participants. Conclusions Low l evels of serum folate may be associated with mortality from all-causes and cardiovascular disease. However, the study lacked power to adequa tely examine the association between folate and disease-specific endpo ints. Additional studies, using serum and other measures of folate nut ritional status, are needed to examine the relationship between folate nutrition and other more specifically defined health outcomes.