The Centers for Disease Control and Prevention report that more people die from lung cancer than breast, prostate and colon cancers combined. The most recent statistics on lung cancer released by the CDC report that in 2006 106,374 men and 90,080 women were diagnosed with lung cancer and 89,243 men and 69,356 women died from lung cancer. The number one risk factor for lung cancer is smoking, and the high amount of oxidants in cigarette smoke contributes to the development of lung cancer. Certain antioxidants have been found to increase lung function and reduce the risk of lung cancer. However, antioxidants obtained from diet, rather than supplements, are a better source for cancer prevention.
Antioxidants
Metabolic processes in the body require oxygen, and the many reactions involving oxygen that occur in a cell produce reactive oxygen species. Reactive oxygen species or ROS can damage cells; therefore cells have several mechanisms that protect against an accumulation of ROS. One mechanism is having an abundant amount of antioxidants, which inhibit the destruction of DNA, proteins and lipids caused by ROS. Many antioxidants include the vitamins, A, C and E, carotenoids, flavonoids, melatonin, glutathione and phenolic acids and esters.
Lung Function
Oxidative stress, caused by an accumulation of ROS, affects many lung functions and contributes to the development of lung diseases, including cancer. A study in the "American Journal of Epidemiology" reports that increased intake of dietary antioxidants improves lung function. However, in this study the effects of particular antioxidants on lung function differed between smokers and non-smokers. Scientific studies have not been able to establish a cause and effect relationship between antioxidants and increased lung function, and much of the evidence is controversial.
Cancer Risk
A study in the "American Journal of Epidemiology" on more than 27,000 male smokers reports that a higher fruit and vegetable intake reduced lung cancer risk by 27 percent. Additionally, this study found that a higher intake of lycopene, found in tomato products, and higher blood levels of vitamin A were also correlated to a significant decrease in lung cancer risk. Many other studies have evaluated the use of antioxidant supplements to suppress lung cancer risk, and the National Cancer Institute notes that data from large clinical trials is inconsistent in finding that particular antioxidants substantially reduce the risk of lung cancer. A review article in the "Proceedings of the Nutrition Society" concludes that while supplementation with antioxidant vitamins cannot be recommended, a diet high in fruit and vegetables that contain multiple antioxidants among other protective chemicals can be recommended to help reduce lung cancer risk.
References
- Centers for Disease Control and Prevention: Lung Cancer Statistics
- American Journal of Epidemiology: Intake of Vitamins E, C, and A and Risk of Lung Cancer
- Proceedings of the Nutrition Society: Vitamins and Respiratory Disease
- American Journal of Epidemiology: Dietary Carotenoids, Serum ß-Carotene, and Retinol and Risk of Lung Cancer in the Alpha-Tocopherol, Beta-Carotene Cohort Study
- National Cancer Institute: Antioxidants and Cancer Prevention Fact Sheet
