EFFECT OF SUPPLEMENTATION WITH BETA-CAROTENE AND VITAMIN-A ON LUNG NUTRIENT LEVELS

The Carotene and Retinol Efficacy Trial (CARET), a randomized, placebo -controlled lung cancer chemoprevention trial of 30 mg of beta-caroten e and 25,000 IU of retinyl palmitate, aas prematurely terminated when a 46% excess lung cancer mortality was found in subjects on the active arm. Before the CARET intervention ended, 21 men sere recruited to pa rticipate in a 6-month biomarker study using the same intervention as CARET that determined the effect of this supplementation on lung nutri ent levels, plasma and bronchoalveolar lavage (BAL) cell nutrient leve ls sere measured before and after the intervention The group in the ac tive arm (n = 10) had plasma beta-carotene level increases of over 10- fold, with a small increase in plasma retinol levels. BAL cell levels of beta-carotene in the active group also increased 10-fold, from 4.5 to 46.3 rho mol/10(6) cells (P = 0.0008), with no change in BAL cell r etinol levels, Surgically obtained lung tissue from three CARET subjec ts in the active arm showed elevated beta-carotene lung tissue levels but no increase in lung retinol levels compared to a group of surgical controls. Combined with our previous work shoeing a strong correlatio n between BAL and lung tissue nutrient levels, these findings suggest that supplementation with beta-carotene and vitamin A results in incre ased lung tissue as well as BAL cell levels of beta-carotene, with lit tle change in lung retinol.