SEATTLE, Nov. 30 (UPI) -- A U.S. study of smokers taking beta-carotene supplements found cardiovascular disease mortality disappeared after the smokers stopped taking the supplements.
However, the risk of lung cancer may persist, especially in females and former smokers, according to the study published in the Wednesday issue of the Journal of the National Cancer Institute.
During the 1980s, preliminary studies suggested beta-carotene might help prevent lung cancer in smokers. But two trials were halted when the supplements were associated with an increased risk of lung cancer. One group of participants receiving beta-carotene supplements had a 28 percent greater incidence of lung cancer and 17 percent more deaths from all causes, as compared with a placebo group.
To follow up, Dr. Gary Goodman of the Fred Hutchinson Cancer Research Center in Seattle followed the more than 18,000 participants in one trial for six years after the trial was stopped, until the end of 2001.
The increased risk of cardiovascular disease mortality quickly disappeared after participants stopped taking the supplements, according to Goodman.
