How do beta carotene and vitamin A affect lung cancer risk?

Advertisement
Advertisement
Dariush Mozaffarian, MD
Internal Medicine
Epidemiological studies suggest that people who eat foods rich in beta carotene and vitamin A are less likely to develop many types of cancer, especially lung cancer. But when researchers tested beta carotene supplements in smokers, they found that people who took the supplements were more likely to develop lung cancer. In one study, people who took 30 mg of beta carotene plus 25,000 international units (IU) of vitamin A were 46% more likely to die of lung cancer than those taking a placebo. Based on these findings, experts now advise people -- especially former and current smokers -- not to take beta carotene supplements.