EFFECTS OF SUPPLEMENTAL BETA-CAROTENE, CIGARETTE-SMOKING, AND ALCOHOL-CONSUMPTION ON SERUM CAROTENOIDS IN THE ALPHA-TOCOPHEROL, BETA-CAROTENE CANCER PREVENTION STUDY

We determined whether serum carotenoid or retinol concentrations were altered by beta-carotene supplementation in the Alpha-Tocopherol, Beta -Carotene Cancer Prevention Study and whether such effects were modifi ed by alcohol consumption or cigarette use. Participants in this subst udy were 491 randomly selected men aged 58-76 y from the metropolitan Helsinki study center [237 receiving supplemental beta-carotene (20 mg /d) and 254 not receiving such supplementation]. Dietary carotenoids, retinol, and alcohol, and serum beta-carotene, alpha-tocopherol, retin al, and cholesterol were assessed at baseline. After an average of 6.7 y of supplementation, serum was collected and carotenoid, retinol, an d alpha-tocopherol concentrations were determined by HPLC. Serum carot enoid fractions were highly correlated with each other (P less than or equal to 0.0001). Compared with the unsupplemented group, the beta-ca rotene group had significantly higher serum concentrations of beta-car otene (1483%), alpha-carotene (145%), and beta-cryptoxanthin (67%) (P less than or equal to 0.0001). Retinol concentrations were 6% higher ( P = 0.03) and lutein was 11% lower (P = 0.02) in the supplemented grou p. Serum lycopene, zeaxanthin, and alpha-tocopherol did not differ acc ording to beta-carotene-supplementation status. Although these beta-ca rotene-group differences were not significantly altered by amount of a lcohol consumption, higher consumption (> 12.9 g/d, median) was relate d to lower (10-38%) concentrations of carotenoids, particularly beta-c arotene, alpha-carotene, and beta-cryptoxanthin, in both the supplemen ted and unsupplemented groups. Smoking status did not significantly in fluence the supplementation-related differences in serum carotenoid an d retinol values but concentrations of carotenoids were generally high est in participants who quit smoking while in the study and lowest ill current smokers of greater than or equal to 20 cigarettes/d. This stu dy showed that serum concentrations of non-beta-carotene: carotenoids are altered by long-term beta-carotene supplementation and confirms th e adverse effects of alcohol and cigarette smoking on serum carotenoid s.