Beta-carotene supplementation in smokers reduces the frequency of micronuclei in sputum.
beta-carotene has been hypothesised to reduce lung cancer risk. We studied the effect of 14 weeks of beta-carotene supplementation (20 mg d-1) on the frequency of micronuclei in sputum in 114 heavy smokers in a double-blind trial. Micronuclei reflect DNA damage in exfoliated cells and may thus provide a marker of early-stage carcinogenesis. Pre-treatment blood levels of cotinine, beta-carotene, retinol and vitamins C and E were similar in the placebo group (n = 61) and the treatment group (n = 53). Plasma beta-carotene levels increased 13-fold in the treatment group during intervention. Initial micronuclei counts (per 3,000 cells) were higher in the treatment group than in the placebo group (5.0 vs 4.0, P < 0.05). During intervention, the treatment group showed a 47% decrease, whereas the placebo group showed a non-significant decrease (16%). After adjustment for the initial levels, the treatment group had 27% lower micronuclei counts than the placebo group at the end of the trial (95% CI: 9-41%). These results indicate that beta-carotene may reduce lung cancer risk in man by preventing DNA damage in early-stage carcinogenesis.
van Poppel
G
G
TNO Toxicology and Nutrition Institute, Zeist, The Netherlands.
Kok
F J
FJ
Hermus
R J
RJ
D000328:Adult; D002338:Carotenoids / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood; D004249:DNA Damage; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D015162:Micronucleus Tests; D008875:Middle Aged; D012880:Skin Pigmentation / Q000187:drug effects; D012907:Smoking / Q000009:adverse effects* / Q000097:blood; D013183:Sputum; D019207:beta Carotene
D019207:beta Carotene; D002338:Carotenoids