Es. Ford et al., SERUM FOLATE AND CHRONIC DISEASE RISK - FINDINGS FROM A COHORT OF UNITED-STATES ADULTS, International journal of epidemiology, 27(4), 1998, pp. 592-598
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.