Antioxidants have been found to protect cells from free radicals; free radical damage has been associated with cancer development, as noted by the National Cancer Institute. Research is still determining the complete role of antioxidants in maintaining a healthy lifestyle; however, for the antioxidant beta carotene, the studies have demonstrated contradictory results. Some research has suggested that beta carotene supplements may increase the risk of lung cancer while other research suggests that this antioxidant may help prevent cancer. Beta carotene may also have other benefits for the lungs as well.
What Is Beta Carotene?
Beta carotene is a member of the carotenoid family and can be converted to vitamin A, according to the National Institutes of Health. Beta carotene can be used to prevent age-related macular degeneration and cataracts; it can also be used to treat diseases like schizophrenia, psoriasis, rheumatoid arthritis and lung conditions. This antioxidant can be found in brightly colored fruits and vegetables such as carrots, spinach, peaches and broccoli but is also available in supplement form. Getting beta carotene from the diet rather than supplements is recommended by multiple scientific authorities until more research is performed on the effects of these supplements. Several of these studies have looked at beta carotene and the lung. The data so far -- which has evaluated both beta carotene in food and supplements -- has varied depending on the patient population and the type of beta carotene.
Beta Carotene and Lung Cancer
Several large studies have looked at the impact of beta carotene on the development of lung disease. One, the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Trial, was held from 1985 to 1993; smokers who took beta carotene supplements had an 18 percent higher incidence of lung cancer and a higher risk of death overall. Another trial, Beta-Carotene and Retinol Efficacy Trial, looked at smokers, former smokers or people who were exposed to asbestos who took beta carotene supplements; the rate of lung cancer was 28 percent higher in the people who took the supplements. In the long-term follow up results published in 2003 in the "Journal of the American Medical Association," the researchers found that these male smokers still had a higher risk of death overall, as noted by the National Cancer Institute. The incidence of lung cancer in these men, however, returned to normal a few years after stopping the supplements. The totality of these findings caused concern about the use of these supplements in people who were at risk of lung cancer.
Benefits of Beta Carotene in the Lungs
Other research has found that beta carotene may be beneficial for people with other types of lung problems. A 1998 study found that eating plenty of fruits and vegetables high in beta carotene may protect the lungs from bronchitis, asthma and other lung diseases, as noted in an article by Susan Lang in the "Cornell Chronicle." Another study by Neuman and colleagues published in the June 1999 issue of the "Annals of Allergy, Asthma, and Immunology" found that a natural form of beta carotene helped prevent exercise-induced asthma in children. Having higher levels of beta carotene in the body also lowered the risk of developing asthma, as noted in a study by Rubin and colleagues which was published in "American Journal of Respiratory and Critical Care Medicine." Eating foods high in beta carotene led to these beneficial results as opposed to taking beta carotene supplements.
What Should You Do?
With evidence suggesting that beta carotene may increase the risk of some lung problems and may be beneficial to other health concerns, you may have questions about your beta carotene intake. Most health care providers recommend avoiding beta carotene supplements -- especially if you smoke because of the risk of lung cancer, according to the National Institutes of Health. High doses of beta carotene supplements may also increase your risk of death from all causes like heart attack or stroke. Eating a healthy diet with plenty of fruits and vegetables, however, may lower your risk of other lung conditions. You should discuss any beta carotene supplementation with your health care provider before you start.
References
- National Cancer Institute: Beta-Carotene Supplements Confirmed as Harmful to Those at Risk for Lung Cancer
- "Annals of Allergy, Asthma, and Immunology"; Prevention of Exercise-Induced Asthma by a Natural Isomer Mixture of Beta-Carotene; Neuman et al; June 1999.
- "American Journal of Respiratory and Critical Care Medicine"; Relationship of Serum Antioxidants to Asthma Prevalence in Youth; Rubin and colleagues; 2004.
- American Cancer Society: Vitamin A and Beta Carotene
- National Cancer Institute: Antioxidants and Cancer Prevention: Fact Sheet
- "Cornell Chronicle"; Study: Beta Carotene Helps Protect Lungs -- Especially of Non-Smokers
- National Cancer Institute: Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Trial
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