Recent studies have suggested that beta-carotene supplements can increase the risk of lung cancer among current, long-term smokers. However, these studies may have been conceived arid executed on a. number of faulty assumptions. There was no evidence to suggest that beta-carotene would protect specifically against lung cancer, particularly in high-risk populations. There are significant isomerk and other differences between the synthetic beta-carotene used in these negative studies and natural beta-carotene supplements; these isomeric differences would suggest different behaviors.

Researchers ignored the likely roles of other carotenoids in health and the possibility that carotenoids, as a group, function synergistically. The evidence supporting the antioxidant and disease-preventive roles of beta-carotene remains strong, but other associated dietary caroterwids, such as alpha-carotene, lycopem, lutein, zeaxanthin, andcryptoxanthin, also play important and likely complementary roles in health. The use of a single synthetic cararotenoid in clinical studies reflects a single drug magic-bullet approach, whereas the evidence suggests that nutrients work as a biochemical team.