THE RISK OF DEVELOPING LUNG-CANCER ASSOCIATED WITH ANTIOXIDANTS IN THE BLOOD - ASCORBIC-ACID, CAROTENOIDS, ALPHA-TOCOPHEROL, SELENIUM, AND TOTAL PEROXYL RADICAL ABSORBING CAPACITY

Lung cancer cases diagnosed during the period 1975 through 1993 and ma tched controls were identified in the rosters of Washington County, Ma ryland residents who had donated blood for a serum bank in 1974 or 198 9. Plasma from participants in the 1989 project was assayed for ascorb ic acid; serum or plasma was assayed for participants in either projec t for alpha- and beta-carotene, cryptoxanthin, lutein/zeaxanthin, lyco pene, alpha-tocopherol, selenium, and peroxyl radical absorption capac ity. Among the total group of 258 cases and 515 controls, serum/plasma concentrations were significantly lower among cases than controls for cryptoxanthin, beta-carotene, and lutein/zeaxanthin with case-control differences of -25.5, -17.1, and -10.1%, respectively. Modest nonsign ificant case-control differences in a protective direction were noted for alpha-carotene and ascorbic acid. There were only trivial differen ces for lycopene, alpha-tocopherol, selenium, and peroxyl radical abso rption capacity. Findings are reported for males and females and for p ersons who had never smoked cigarettes, former smokers, and current sm okers at baseline. These results and those from previous studies sugge st that beta-carotene is a marker for some protective factor(s) agains t lung cancer; that cryptoxanthin, alpha-carotene, and ascorbic acid n eed to be investigated further as potentially protective factors or as sociates of a protective factor; and that lycopene, cu-tocopherol, sel enium, and peroxyl radical absorption capacity are unlikely to be asso ciated with lung cancer risk. Until specific preventive factors are id entified, the best protection against lung cancer is still the avoidan ce of airborne carcinogens, especially tobacco smoke; second best is t he consumption of a diet rich in fruits and vegetables.