Beta-carotene's effects on serum lipoproteins and immunologic indices in humans.
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.
Ringer
T V
TV
Upjohn Research Clinics, Upjohn Company, Kalamazoo, MI 49007.
DeLoof
M J
MJ
Winterrowd
G E
GE
Francom
S F
SF
Gaylor
S K
SK
Ryan
J A
JA
Sanders
M E
ME
Hughes
G S
GS
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
D008074:Lipoproteins; D019207:beta Carotene; D014801:Vitamin A; D014810:Vitamin E; D002338:Carotenoids; C041635:alpha-carotene; D000077276:Lycopene; D014975:Lutein