title: Beta-carotene's effects on serum lipoproteins and immunologic indices in humans.
abstract: Doses of beta-carotene for cancer-prevention trials have been chosen based on epidemiologic data. Mechanisms of the putative antineoplastic effects by beta-carotene are unknown but may involve modulation of the immune system. We measured plasma carotenoid concentrations and selected immunologic indices at baseline and at 2 and 4 wk in 50 healthy humans (5 groups of 10 each) ingesting 0, 15, 45, 180, or 300 mg beta-carotene/d for 1 mo in this randomized placebo-controlled, open-label, parallel study. Plasma beta-carotene concentrations were markedly increased by 2 wk and were correlated with dose. Beta-carotene concentrations plateaued between 2 and 4 wk except for the 300-mg group. Thus, we developed a dose-concentration curve to optimize beta-carotene-dose selection to achieve target plasma concentrations. We were unable to identify any effects of beta-carotene ingestion on the immunologic indices studied, but modest increases in high-density-lipoprotein cholesterol were observed in all beta-carotene-treated groups.
authors.affiliation: Upjohn Research Clinics, Upjohn Company, Kalamazoo, MI 49007.
authors.forename: T V
authors.initials: TV
authors.lastname: Ringer
authors.forename: M J
authors.initials: MJ
authors.lastname: DeLoof
authors.forename: G E
authors.initials: GE
authors.lastname: Winterrowd
authors.forename: S F
authors.initials: SF
authors.lastname: Francom
authors.forename: S K
authors.initials: SK
authors.lastname: Gaylor
authors.forename: J A
authors.initials: JA
authors.lastname: Ryan
authors.forename: M E
authors.initials: ME
authors.lastname: Sanders
authors.forename: G S
authors.initials: GS
authors.lastname: Hughes
mesh_terms: D000328:Adult; D002338:Carotenoids / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007109:Immunity / Q000187:drug effects*; D007958:Leukocyte Count; D008074:Lipoproteins / Q000097:blood*; D014975:Lutein / Q000097:blood; D000077276:Lycopene; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000517:prevention & control; D014801:Vitamin A / Q000097:blood; D014810:Vitamin E / Q000097:blood; D019207:beta Carotene
chemical_list: D008074:Lipoproteins; D019207:beta Carotene; D014801:Vitamin A; D014810:Vitamin E; D002338:Carotenoids; C041635:alpha-carotene; D000077276:Lycopene; D014975:Lutein