Effect of long-term beta-carotene and vitamin A on serum cholesterol and triglyceride levels among participants in the Carotene and Retinol Efficacy Trial (CARET)

Carrie A. Redlich, Joyce S. Chung, Mark R. Cullen, William S. Blaner, Ariette M. Van Bennekum, Lars Berglund

Research output: Contribution to journalArticle

18 Scopus citations


Objective: The Carotene and Retinol Efficacy Lung Cancer Chemoprevention Trial (CARET) ended prematurely due to the unexpected findings that the active treatment group on the combination of 30 mg β-carotene and 25 000 IU retinyl palmitate had a 46% increased lung cancer mortality and a 26% increased cardiovascular mortality compared with placebo. This study was designed when the CARET intervention was halted to evaluate the effects of long-term supplementation with β-carotene and retinol on serum triglyceride and cholesterol levels, in an attempt to explore possible explanations for the CARET result. Methods: Serum triglyceride levels, and total, high- density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol levels were determined in a subgroup of 52 CARET participants. Baseline and mid-trial levels were available on 23 participants on placebo and 29 on active treatment who were then serially followed for 10 months after trial termination. Results: Triglyceride, and total, HDL and LDL cholesterol levels were similar in the two groups at baseline. After a mean of 5 years on the intervention there was a small nonsignificant increase in serum triglyceride levels in the active group, but no difference in total, HDL, or LDL cholesterol levels. After stopping the intervention there was a decrease in triglyceride levels in the active intervention group, and no change in the other parameters. Conclusion: Based on a small convenience sample, CARET participants in the active treatment arm had a small nonsignificant increase in serum triglyceride levels while on the intervention, and a decrease in serum triglyceride levels after the intervention was discontinued. No significant changes in total or HDL cholesterol were noted. These results argue against a major contribution of treatment-induced changes in serum lipid and lipoprotein levels to the increased cardiovascular mortality in the active treatment group.

Original languageEnglish (US)
Pages (from-to)427-434
Number of pages8
Issue number2
StatePublished - 1999
Externally publishedYes



  • Cholesterol
  • High-density lipoprotein (HDL)
  • Triglyceride
  • Vitamin A
  • β-Carotene

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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