The research by scientists at the International Agency for Research on Cancer (IARC), which has been published in the Journal of the American Medical Association (JAMA), has found that people with above average levels of Vitamin B6 and methionine –a related nutrient – are half as likely to develop the disease. The results were similar for smokers, non-smokers and ex-smokers.
And for those people with high levels of vitamins B6 and folate as well high levels of methionine, there was a two-thirds lower risk of lung cancer.
But while the findings are being seen as significant, more research is needed before scientists can be confident that increasing levels of B-vitamins in the diet can reduce risk of lung cancer and also to understand how this works.
Researchers are warning that even if the results were confirmed by further studies, any impact on lung cancer risk from B-vitamins would be much smaller than for smoking.
Dr Paul Brennan, the lead researcher of the study, said: “More research is needed to confirm that B-vitamins actually reduce risk of lung cancer. However, these results are significant because the reduction in risk was consistent among current smokers, former smokers, and people who had never smoked.
“If further research does confirm our findings then the next step would be to identify the optimum B-vitamin levels for reducing future cancer risk.
Dr Panagiota Mitrou, Science Programme Manager for WCRF, said: “These findings are really exciting as they are important for understanding the process of lung cancer and could have implications for prevention.
“But while this is an important study, it is vital that we get the message across to smokers that increasing intake of B-vitamins is not – and never will be– a substitute for stopping smoking. However, we should also recognise that a significant number of lung cancer cases occur among people who have never smoked or who have stopped smoking. This means that for ex-smokers and people who have never smoked, the findings of this study could mean that these people can do something positive to reduce their risk of lung cancer.
“But it is important that any work in this area does not detract from the good work going on around the world to reduce smoking rates. This is because for lung cancer, smoking is by far the biggest risk factor. It is also important to emphasise that this study does not show that taking B vitamins in supplements will be effective.”
Previous research has shown that about a third of the most common cancers in the UK could be prevented through eating a healthy diet, being physically active and maintaining a healthy weight. WCRF recommends not using supplements to protect against cancer.
For more information contact Richard Evans on 020 7343 4253.
Notes to editors:
For the study, the researchers looked at 899 people who had donated blood as part of the European Prospective Investigation into Cancer and Nutrition (EPIC) – a larger population cohort of more than 500,000 participants from 10 European countries- and then later went on to develop lung cancer, as well as 1,770 people who had donated blood and did not develop the disease.
The advantage of looking at the levels of B-vitamins in the blood samples taken many years before disease onset is that they are not affected by disease status and may be a much more accurate way of measuring dietary consumption than through food diaries or food frequency questionnaires, which rely on people’s memory and have been shown to be less reliable.
Foods rich in B-vitamins and related nutrients include fruits and leafy green vegetables (folate), fortified cereals and wholegrains (vitamin B6), as well as meat and various seeds, nuts, fish and meats (methionine).
World Cancer Research Fund (WCRF) raises awareness that cancer is largely preventable and helps people make choices to reduce their chances of developing the disease.
This includes research into how cancer risk is related to diet, physical activity, and weight management, and education programmes that highlight the fact that about a third of cancers could be prevented through changes to lifestyle. For more information on the charity’s work, visit www.wcrf-uk.org
The WCRF report, called Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective, was launched in November 2007 and is the most comprehensive report ever published on the link between cancer and lifestyle. For more information, visit www.dietandcancerreport.org