title: Plasma carotenoids and prostate cancer: a population-based case-control study in Arkansas.
abstract: Carotenoids possess antioxidant properties and thus may protect against prostate cancer. Epidemiological studies of dietary carotenoids and this malignancy were inconsistent, partially due to dietary assessment error. In this study, we aimed to investigate the relation between plasma concentrations of carotenoids and the risk of prostate cancer in a population-based case-control study in Arkansas. Cases (n = 193) were men with prostate cancer diagnosed in 3 major hospitals, and controls (n = 197) were matched to cases by age, race, and county of residence. After adjustment for confounders, plasma levels of lycopene, lutein/zeaxanthin, and beta-cryptoxanthin were inversely associated with prostate cancer risk. Subjects in the highest quartile of plasma lycopene (513.7 microg/l) had a 55% lower risk of prostate cancer than those in the lowest quartile (140.5 microg/l; P trend = 0.042). No apparent association was observed for plasma alpha-carotene and beta-carotene. Further adjustment for the other 4 carotenoids did not materially alter the risk estimates for plasma lycopene, lutein/zeaxanthin, and beta-cryptoxanthin but appeared to result in an elevated risk with high levels of plasma alpha-carotene and beta-carotene. The results of all analyses did not vary substantially by age, race, and smoking status. This study added to the emerging evidence that high circulating levels of lycopene, lutein/zeaxanthin, and beta-cryptoxanthin are associated with a low risk of prostate cancer.
authors.affiliation: Department of Epidemiology, Fay W Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA. zhangjianjun@uams.edu
authors.forename: Jianjun
authors.initials: J
authors.lastname: Zhang
authors.forename: Ishwori
authors.initials: I
authors.lastname: Dhakal
authors.forename: Angie
authors.initials: A
authors.lastname: Stone
authors.forename: Baitang
authors.initials: B
authors.lastname: Ning
authors.forename: Graham
authors.initials: G
authors.lastname: Greene
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Lang
authors.forename: Fred F
authors.initials: FF
authors.lastname: Kadlubar
mesh_terms: D000975:Antioxidants / Q000378:metabolism* / Q000627:therapeutic use; D001131:Arkansas / Q000453:epidemiology; D002338:Carotenoids / Q000097:blood* / Q000627:therapeutic use; D016022:Case-Control Studies; D065366:Cryptoxanthins; D006801:Humans; D014975:Lutein / Q000097:blood / Q000627:therapeutic use; D000077276:Lycopene; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000097:blood* / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D012307:Risk Factors; D024341:Xanthophylls / Q000097:blood / Q000627:therapeutic use; D065146:Zeaxanthins; D019207:beta Carotene / Q000097:blood
chemical_list: D000975:Antioxidants; D065366:Cryptoxanthins; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D002338:Carotenoids; C041635:alpha-carotene; D000077276:Lycopene; D014975:Lutein