Effect of beta-carotene on immunological indexes in healthy male smokers

Am J Clin Nutr. 1993 Mar;57(3):402-7. doi: 10.1093/ajcn/57.3.402.


To evaluate the immunomodulatory effects of beta-carotene we performed a randomized, double-blind trial in healthy male cigarette smokers. Lymphocyte subsets in peripheral blood were assessed by using double labeling with monoclonal antibodies before and after 14 wk beta-carotene (20 mg/d; n = 21) or placebo (n = 24) supplements. In addition we measured the ex vivo phytohemagglutinin and concanavalin A induced lymphocyte proliferation in a separate group (23 placebo, 24 beta-carotene). The beta-carotene and placebo groups were comparable on all initial characteristics. During the intervention plasma concentrations of beta-carotene increased 13-fold in the treatment group whereas retinol concentrations remained constant. Beta-carotene had no effect on lymphocyte subpopulations in peripheral blood. After treatment the beta-carotene group showed 12% higher PHA-induced lymphocyte proliferations than the placebo group (P = 0.02). For ConA induced proliferations no significant difference was observed. These results suggest that supplementary beta-carotene can moderately enhance certain aspects of immune response in healthy male cigarette smokers.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies, Monoclonal
  • Carotenoids / blood
  • Carotenoids / pharmacology*
  • Carotenoids / therapeutic use
  • Concanavalin A / pharmacology
  • Double-Blind Method
  • Humans
  • Leukocyte Count
  • Lymphocyte Activation / drug effects
  • Lymphocyte Subsets / drug effects
  • Male
  • Middle Aged
  • Phytohemagglutinins / pharmacology
  • Smoking / blood*
  • Vitamin A / blood
  • beta Carotene


  • Antibodies, Monoclonal
  • Phytohemagglutinins
  • beta Carotene
  • Concanavalin A
  • Vitamin A
  • Carotenoids