Higher blood levels of vitamin B6 and common amino acids are associated with lower lung cancer risk

According to a JAMA study, an analysis involving nearly 400000 participants found that those with higher blood levels of vitamin B6 and essential amino acid methionine (which is present in most proteins) are associated with lower risk of lung cancer, including those who currently smoke or have previously smoked   Previous studies have suggested that the lack of B vitamins can increase the probability of DNA damage and gene mutation "Given their role in maintaining DNA integrity and gene expression, these nutrients may play a potentially important role in inhibiting the development of cancer, and they also offer the possibility of modifying cancer risk through dietary changes," the authors write   Paul Brennan, Ph.D of International Agency for research on cancer, Lyon, France and their colleagues conducted a survey on B vitamins and methionine based on serum samples from the European Prospective Investigation into cancer and nutrition (EPIC) group study A total of 519978 participants from 10 European countries were recruited in the group study, covering the period 1992-2000 Of these, 385747 have donated blood By 2006, 899 lung cancer cases had been found in the small group, and 1770 control participants had matched individuals in their countries, genders, birthdays, and blood sample collection dates   After analyzing the incidence rate of lung cancer in the EPIC group and correcting all the factors, the researchers found that among those whose B6 concentration increased, the risk of lung cancer was lower (the comparison was the 44 percentile of B6 blood concentration, vs 14 percentile) In addition, the increase of methionine concentration will also reduce the risk of lung cancer "Similar and consistent reductions in lung cancer risk have been found among non-smokers, former smokers and current smokers, suggesting that these results are not driven by the confounding factor of smoking [i.e., the factors that influence the results]," the researchers wrote The magnitude of the risk also remained constant over the extended follow-up period, suggesting that this association cannot be explained by preclinical disease "   When these participants were classified by median (median) serum methionine and B6 levels, those with both concentrations higher than median were associated with a lower overall lung cancer risk Increased serum folate levels moderately reduced the risk of lung cancer, but the association was limited to former and current smokers, but was not significant among never smokers   "Our results suggest that both B6 and methionine levels higher than the median serum concentration (estimated from an average of five years before the onset of the disease) are associated with a reduction in lung cancer risk of at least 50 percent," the authors write There is also an additional correlation between folate and serum folate concentrations, and when folate is combined with B6 and methionine, they are associated with a 2 / 3 reduction in lung cancer risk "   The researchers added that if there is a causal relationship between what they observed about serum methionine, B6 or both of these phenomena that reduce the risk of lung cancer, it seems appropriate to find the optimal blood concentration of these substances that reduce the risk of future cancer   "Lung cancer is still the most common cause of cancer deaths in the world today and is likely to remain so in the near future," the authors conclude It is crucial for lung cancer prevention that any additional evidence of a causal link in lung cancer does not diminish the importance of reducing smoking With this in mind, it's very important for people to see that a large proportion of lung cancer cases occur in former smokers, who account for the majority of lung cancer patients in countries where the anti smoking campaign has been particularly successful; a significant number of lung cancer cases also occur in those who never smoke, especially those who live in some parts of Asia Women in the district Clarifying the role of B vitamins and related metabolites in lung cancer risk may therefore be of particular relevance to former and never smokers "