No influence of beta-carotene on haemostatic balance in healthy male smokers.

A high intake of beta-carotene has been associated with a decreased risk for cardiovascular disease. To evaluate whether beta-carotene may exert a protective effect through an impact on haemostasis a randomized, placebo-controlled trial was conducted in male smokers (n = 149) using 20 mg/day beta-carotene for 14 weeks. For comparisons, haemostatic indicators were also evaluated in a group of non-smokers (n = 54). Smokers compared with non-smokers had higher fibrinogen (3.5 vs. 3.1 mg/ml, P < 0.01), higher tissue-type plasminogen activator antigen (t-PA; 8.03 vs. 6.60 ng/ml, P < 0.05), lower levels of soluble fibrin (3.40 vs. 5.16 micrograms/ml, P < 0.01) and slightly higher plasma levels of total degradation products of fibrin and fibrinogen (TDP; 47.0 vs. 41.3 ng/ml, P = 0.21). Within the group of smokers, there were no initial differences in the four haemostatic indicators between the placebo (n = 77) and beta-carotene (n = 72) groups, and in both groups there was virtually no change in the indicators during the 14 weeks treatment. It is concluded that the different haemostatic profile in smokers may partly explain their increased risk for cardiovascular disease. beta-Carotene has no influence on the measured haemostatic indicators, and cardiovascular protection for beta-carotene via a beneficial effect on haemostasis seems improbable.