Lutein, a nutrient commonly found in the North American diet, may have powerful antioxidant properties that scientists believe may help lower your risk of developing lung cancer. While early studies have shown promising results, findings are conflicting, and further research is necessary to support the use of lutein as an anticancer agent.
Lung Cancer
In the United States, lung cancer is the most common cause of death from any type of cancer for both men and women, according to the National Cancer Institute. Symptoms of the disease may include shortness of breath, chest pain, wheezing, a cough that worsens with time, coughing up blood, chronic lung infections, fatigue and weight loss. Cigarette smoking is the leading cause of lung cancer, and it is responsible for more than 75 percent of lung cancer deaths in men and women, the Centers for Disease Control and Prevention reports. Air pollution, a family history of the disease, and exposure to secondhand smoke, radon gas, asbestos and other chemicals may also increase your risk of developing lung cancer. Treatment for the condition depends on the type and extent of your cancer, but it may include surgery, radiation therapy, chemotherapy or a combination of treatments.
Lutein
Lutein is a substance that occurs naturally in egg yolks and certain fruits and vegetables. It is a carotenoid, a family of chemicals that helps give fruits and vegetables their yellow, orange or red color. Good sources of lutein include kale, spinach, collard greens, peas, broccoli, papayas, mango, peaches and oranges. In humans, the substance also forms the yellow pigment in the center of the retina, and it is an important antioxidant that may help prevent disease. Research suggests that lutein reduces the risk of eye diseases such as cataracts and macular degeneration, and it may lower the risk of heart disease and certain cancers, notes the Memorial Sloan-Kettering Cancer Center. Recommended daily intake for lutein has not been determined, but studies show that 10 mg per day of the nutrient may provide health benefits, the American Optometric Association reports.
Dietary Lutein
Dietary studies examining the protective effects of lutein on lung cancer development are conflicting. Preliminary studies show that a greater dietary intake of lutein lowers the risk of lung cancer, while others have found no relationship or a weak association. In a review of more than 25 studies on the topic in an August 2008 issue of "The American Journal of Clinical Nutrition," Lisa Gallicchio and colleagues found that lutein lowered the risk of lung cancer by only 5 percent, a statistically insignificant amount. However, the researchers did note a significant health benefit for those with the highest intake of all carotenoids, including beta-carotene, alpha-carotene, beta-cryptoxanthin, lycopene and lutein-zeaxanthin. These individuals had a 21 percent lower risk of developing lung cancer as those with the lowest intake of all carotenoids.
Lutein Supplements
Supplements containing a single carotenoid often have much higher levels of the substances than that found in multivitamins or dietary sources. According to a study of more than 77,000 people published in the April 2009 issue of the "American Journal of Epidemiology," use of lutein supplements over a 10-year period increased the risk of all types of lung cancer by 102 percent. The researchers found that the longer study participants took the supplements in doses higher than in a typical multivitamin, the greater the risk of lung cancer. The authors of the study suggest that intake of the nutrient in high levels may interfere with the absorption of other beneficial carotenoids or nutrients that could protect against the condition.
References
- National Cancer Institute: A Snapshot of Lung Cancer
- Centers for Disease Control and Prevention: Lung Cancer - Risk Factors
- Memorial Sloan-Kettering Cancer Center: Lutein
- American Optometric Association: Lutein and Zeaxanthin
- "The American Journal of Clinical Nutrition"; Carotenoids and the Risk of Developing Lung Cancer: A Systematic Review; Lisa Gallicchio, et al.; August 2008
- "American Journal of Epidemiology"; Long-Term Use of Beta-Carotene, Retinol, Lycopene and Lutein Supplements and Lung Cancer Risk: Results from the Vitamins and Lifestyle Study; Jessie A. Satia, et al.; April 2009
