english.prescrire.org > Spotlight > Archives : 2010 > Smokers: no beta-carotene supplements

Spotlight: Archives

Every month, the subjects in Prescrire’s Spotlight.

2010 : 1 | 30 | 60 | 90

Smokers: no beta-carotene supplements

Beta-carotene supplements increase the risk of lung cancer in smokers, contrary to expectations.

Studies carried out in the 1990s suggested that a diet rich in fruit and vegetables was linked to a decreased risk of lung cancer.

Because of its antioxidant properties, beta-carotene, a vitamin A precursor present in large quantities in fruit and vegetables, was thought to play a part in the primary prevention of lung cancer. Studies were then conducted to evaluate the effectiveness of beta-carotene supplements, especially in smokers.

The findings were contrary to expectations. A statistical analysis of the effects on over 100,000 people revealed a statistically significant increase in the risk of lung cancer in smokers taking beta-carotene in the form of dietary supplement with an average daily dose of 20 mg to 30 mg.

In practice, if smokers want to reduce their lung cancer risk, it is better to stop smoking rather than to rely on beta-carotene.

©Prescrire July 2010

"Lung cancer associated with beta-carotene supplementation in smokers" Prescrire Int 2010; 19 (107): 121 (pdf, subscribers only)
Download the full review 
Pdf, subscribers only