New research has found a link between taking high-dose long term supplementation of vitamins B6 and B12 and an increased risk of lung cancer in men.
However, previously the supplements have been thought to reduce the risk of cancer, and have been long believed to be beneficial for health by increasing energy and improving metabolism, even used in high doses by some top athletes to help boost performance.
Carried out by a team from The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC – James), Fred Hutchinson Cancer Research Center, and National Taiwan University, the research is the first prospective, observational study to look at the effect of taking high-dose B6 and B12 supplements long term on the risk of lung cancer.
For the study the team analysed data from 77,118 participants aged between 50 and 76 who were taking part in the VITamins And Lifestyle (VITAL) cohort study, designed to evaluate whether vitamin and mineral supplements can have an effect on the risk of cancer.
At the start of the study the participants were asked to report on their B-vitamin usage over the past 10 years, including information on the dosages they had taken – a vital but often overlooked detail.
After using statistical techniques which take into account other risk factors including smoking status, age, race, education, body size, alcohol consumption, personal history of cancer or chronic lung disease, family history of lung cancer and use of anti-inflammatory drugs, the team found that high doses of B6 and B12 were linked to a two- to four-fold increased lung cancer risk in men.
Risk of cancer higher for men who smoke
The risk of lung cancer was even higher for those who smoked and took more than 20 mg of B6 a day for 10 years, with these participants three times more likely to develop lung cancer, while male smokers taking more than 55 micrograms of B12 a day for 10 years were around four times more likely to develop the disease compared to non-users.
However, Theodore Brasky of the OSUCCC – James also pointed out that the findings are related to high doses of vitamin B supplements that are well above doses found in taking a multivitamin every day for 10 years.
More studies on vitamin B
Researchers at the The OSUCCC – James are also carrying out two further studies to research the link between B6 and B12 supplementation and lung cancer risk further, including examining whether associations can also be found in post-menopausal women, as current findings suggest that there is no elevated risk in women.
The findings can be found published online in the Journal Of Clinical Oncology. – AFP Relaxnews