B-vitamins may prevent lung cancer

Taking vitamin B6 and amino acid methionine supplements or having high intake of these nutrients may help prevent lung cancer, a study published in the June 2010 issue of American Journal of Medical Association suggests. 

The study led by Mattias Johansson at the International Agency for Research on Cancer (IARC), Lyon, France and colleagues found serum levels of vitamin b6 and methionine were inversely correlated with the risk of lung cancer. 

Johansson et al followed for at least six years 519,978 men and women from 10 countries who were enrolled in the European Prospective Investigation into Cancer and Nutrition (EPIC) between 1992 and 2000. Of these participants, 385,747 donated blood samples for analysis of vitamin B2, B6, folate, B12, methionine and homocysteine. 

During the follow -up, 899 lung cancer cases and 1,770 controls without the disease were identified, but were  matched by country, sex, date of birth and date for blood collection, to be compared with the cases. 

Overall, incidences of lung cancer in men were 6.6, 44.9 and 156.1 per 100,000 person-years among never, former and current smokers respectively.  For women, the corresponding incidences were 7.1, 23.9 and 100.9 per 100,000 person-years. 

Those with highest serum levels of b6 and serum methionine were 56 percent and 48 percent less likely to develop lung cancer respectively compared with those with lowest levels. 

Highest levels of serum folate were associated with 32 percent reduced risk of lung cancer among former and current smokers. 

Those with the above-mean levels of serum methionine and b6 were 59 percent less likely to have lung cancer compared to those with the below mean levels.  Among the never, former and current smokers, the risk was reduced by 64 percent, 49 percent and 58 percent respectively. 

The researchers explained in their study report that "B vitamins and factors related to one-carbon metabolism help maintain DNA integrity and regulate gene expression."

By David Liu and edited by Rachel Stockton