Beta-carotene Increases Lung Cancer Risk in Smokers

Beta-carotene, a nutrient found in many multivitamin supplements and the foremost nutrient in multivitamins taken to boost vision is found to increase a smoker's chances of developing lung cancer, a new study has found.

According to research from the H. Lee Moffitt Cancer and Research Institute at the University of South Florida at Tampa, smokers who consume multivitamins that contain beta-carotene in high doses (20- 30 milligrams per day) are 24 percent more likely to develop lung cancer than smokers who don't take supplements with beta-carotene. For this reason, smokers are urged to monitor their intake of beta-carotene in vitamin supplement and avoid vitamins that promote a healthy vision as they are rich in beta-carotene.

Drs. Tawee Tanvetyanon and Gerold Bepler, researchers from H. Lee Moffitt, along with analyzing the link between high dose beta-carotene and lung cancer in smokers, also analyzed the amount of beta-carotene found in many popular supplements. The researchers found that of the 47 multivitamin supplements studied most contained 0.3 milligrams of beta-carotene per daily dosage, with the content per daily dosage ranging from zero - 17 milligrams among the many multivitamin supplements.

Similarly, the researchers looked at 17 multivitamin supplements used to boost vision and found that most of these vitamins contained 3 milligrams of beta-carotene per daily dosage, while others contained a low of 0.3 milligrams and a high of 24 milligrams per daily dosage.

Is there really cause for concern?

Most multivitamin supplements contain only 0.3 milligrams of beta-carotene per daily dosage, far below the 20-30 milligrams that would put smokers at a 24 percent more risk of developing lung cancer. But as people will take several multivitamins per day or several different multivitamins for that matter, Dr. Tanvetyanon believes that the small amounts of beta-carotene could eventually add up and place smokers at an increased risk for getting lung cancer.

Moreover, smokers who are not vigilant about the beta-carotene content in the multivitamin supplement may very well be taking a supplement with a high beta-carotene content several times a day, unknowingly putting themselves at an increased risk for lung cancer.

Dr. Tanvetyanon pressed for the link between high dose beta-carotene and increased lung cancer risk among smokers to become more public. He criticized the inadequate labeling of multivitamin supplements that give little or no warning about multivitamin and smoking, saying that the best warning he has seen on a vitamin label only warned that smokers and ex-smokers should consult their doctors before taking the supplement.

The study found no link between beta-carotene levels and an increased risk for lung cancer among ex-smokers, however.