Lung cancer, which usually develops in the cells lining air passages, will be diagnosed in about 222,520 Americans this year, according to the National Cancer Institute (NCI). In addition, the NCI says nearly half that many people — about 157,300 — will die from the disease in 2010.
Although lung cancer is notoriously difficult to treat successfully, French scientists have discovered several natural substances that offer substantial protection from the malignancy. In a huge study of almost 400,000 participants, those who had higher blood levels of vitamin B6 and the essential amino acid methionine (found in many forms of protein) had the lowest risk of lung cancer — even those who were former or current smokers.
For the study, which was just published in the Journal of the American Medical Association (JAMA), Paul Brennan, Ph.D., of the International Agency for Research on Cancer, Lyon, France, and colleagues documented B vitamins and methionine levels based on serum samples from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort study. In all, they investigated 385,747 research subjects from 10 European countries. By 2006, 899 had been diagnosed with lung cancer; they were compared to 1,770 control participants and all were individually matched by country, sex, date of birth, and date of blood collection.
The results of the researchers’ analysis revealed a dramatically lower risk for lung cancer among participants with the highest blood levels of B6 and methionine. In addition, a moderately lower risk for lung cancer in former and current smokers was observed in those with higher serum levels of folate.
“Similar and consistent decreases in risk were observed in never, former, and current smokers, indicating that results were not due to confounding (factors that can influence outcomes) by smoking. The magnitude of risk was also constant with increasing length of follow-up, indicating that the associations were not explained by preclinical disease,” the researchers stated in their JAMA article.
50 percent reduction in lung cancer
“Our results suggest that above-median serum measures of both B6 and methionine, assessed on average five years prior to disease onset, are associated with a reduction of at least 50 percent on the risk of developing lung cancer. An additional association for serum levels of folate was present, that when combined with B6 and methionine, was associated with a two-thirds lower risk of lung cancer,” the scientists wrote.
So how could these natural substances keep lung cancer at bay? The key may be found in previous research which has shown that B vitamin deficiencies likely increase the probability of DNA damage and subsequent gene mutations. “Given their involvement in maintaining DNA integrity and gene expression, these nutrients have a potentially important role in inhibiting cancer development, and offer the possibility of modifying cancer risk through dietary changes,” the authors concluded. They also pointed out that B vitamin deficiencies are known to be high in many western populations.