CHANGES IN SERUM CAROTENOIDS IN SUBJECTS WITH COLORECTAL ADENOMAS AFTER 24 MO OF BETA-CAROTENE SUPPLEMENTATION

The effect of beta-carotene supplementation on major serum carotenoid fractions (lutein/zeaxanthin, beta-cryptoxanthin, lycopene, alpha-caro tene, and beta-carotene) was investigated in 224 people with colorecta l adenomas (139 men, 85 women) recruited for the Australian Polyp Prev ention Project (APPP). Each subject was randomly assigned to take eith er 20 mg beta-carotene/d or placebo over 24 mo. Besides the expected i ncrease in serum concentration of beta-carotene (1073% in men, 839% in women), lycopene (176% in men) and alpha-carotene (211% in men and 16 6% in women) concentrations were also increased after body mass index, baseline concentration, change in respective carotenoid intake, and o ther confounding factors were adjusted for. The increase in serum conc entrations of these carotenoids after beta-carotene supplementation su ggests that beta-carotene may interact biologically with other caroten oids and such interaction would need to be taken into consideration wh en the protective effect of beta-carotene supplementation for cancer o r other diseases is examined.