Nc. Armstrong et al., REFERENCE VALUES FOR ALPHA-TOCOPHEROL AND BETA-CAROTENE IN THE WHITEHALL-II STUDY, Free radical research, 27(2), 1997, pp. 207-219
Plasma alpha-tocopherol, beta-carotene, serum lipids and their derived
ratios were determined in British Civil Servants (n = 7177) at the se
cond medical examination of the Whitehall II Study, a longitudinal stu
dy of cardiovascular disease. For plasma alpha-tocopherol the non-para
metric 95% reference interval (90% confidence limits) for the total po
pulation was: 11.1 (10.9-11.3) - 51.5 (50.6-52.7) mu mol/l. For plasma
beta-carotene the nonparametric reference interval for the total popu
lation was: 0.05 (0.05-0.05) - 2.14 (2.08-2.21) mu mol/l. The latter i
nterval was wider than those previously published with a higher mean (
0.61 mu mol/l) and median (0.75 mu mol/l). Plasma beta-carotene concen
trations were higher in women than men with age-adjusted means of 0.70
and 0.57 mu mol/l respectively (p < 0.001). This may reflect differen
ces in diet, lifestyle and metabolism between the sexes. The alpha-toc
opherol/cholesterol ratio, as in other surveys, did not vary with age.
Among men, current- and ex-smokers had a higher alpha-tocopherol/chol
esterol ratio than never-smokers with age-adjusted means of 4.18, 4.19
mu mol/mmol and 4.05 mu mol/mmol respectively. This difference is as
yet unexplained. Follow-up of these subjects will help to clarify the
role of antioxidant nutrients as protective factors for cardiovascular
disease and cancer.