Multivitamins may cut lung cancer risk in current and former smokers

January 18, 2010

     Multivitamins, folate, and green leafy vegetables may reduce the risk of developing lung cancer in current and former smokers, says a new study from the US. When a person smokes the chemicals in the smoke cause a chemical molecule to tag specific genes and this turns the genes off (this process of carbon tagging is called methylation). Unfortunately the genes that do not work well anymore are those related to suppressing cancer. Higher intakes of certain micronutrients reduce the methylation-tagging process which affects gene signaling. Many genes involved in critical cell functions, including cell division, are methylated in lung tumors, and the ability to impede this shows the potential of the micronutrients to reduce the risk of lung cancer
     The researchers, led by Steven Belinsky, PhD, from the Lovelace Respiratory Research Institute in Albuquerque took sputum samples from just over 1,100 current and former smokers participating in the Lovelace Smokers Cohort. Participants also completed questionnaires regarding their dietary intake. The sputum samples were used to examine the degree of methylation of eight genes commonly silenced in lung cancer and associated with risk for this disease. People who ate at least 12 servings of green leafy vegetables per month had a 17 per cent lower risk of methylation, while a daily intake of at least 750 micrograms of the B-Complex Vitamin Folic Acid was associated with a 16 per cent lower risk. Current multivitamin users had a 43 per cent lower risk of gene methylation, added the researchers. The new study, supported by the US National Cancer Institute (NCI), part of the National Institutes of Health, showed that reduced gene methylation occurred with intake of multivitamin supplements that are rich in phytochemicals, such as vitamin C, carotenoids, Lutein, folic acid, and vitamins A and K. The study findings are published online ahead of print in the journal Cancer Research