Jury still out over vitamin E supplements and increased lung cancer risk
Certain vitamins may increase the risk of lung cancer, a new US study has concluded.
A number of studies of vitamin supplements have arrived at different conclusions, with some suggesting they have a beneficial effect on cancer risk while others found they make no difference.
The latest study looked at 77,126 men and women between the ages of 50 and 76 in order to determine the effect of vitamin use on their risk of developing lung cancer over a four-year period.
The findings are published in the American Journal of Respiratory and Critical Care Medicine.
A total of 521 people developed lung cancer during the course of the study. But the researchers, from the University of Washington in Seattle, found that vitamin supplements did not provide any protection against the disease.
Study author Dr Christopher Slatore commented: "Our study of supplemental multivitamins, vitamin C, vitamin E and folate did not show any evidence for a decreased risk of lung cancer.
"Indeed, increasing intake of supplemental vitamin E was associated with a slightly increased risk of lung cancer."
The study suggests that the risk of lung cancer increases by seven per cent for every additional 100 mg/day of vitamin E, with the risk being particularly noticeable among smokers.
Dr Slatore revealed: "This risk translates into a 28 per cent increased risk of lung cancer at a dose of 400 mg/day for ten years.
"Our results should prompt clinicians to counsel patients that these supplements are unlikely to reduce the risk of lung cancer and may be detrimental."
Henry Scowcroft, senior science information officer at Cancer Research UK, said: "The jury's still very much out on whether vitamin and mineral supplements can affect cancer risk. Some studies suggest a benefit, but many others show no effect and some, like this one, suggest they may even increase risk.
"Research repeatedly shows that a healthy, balanced diet can reduce your risk of some cancers while giving you all the vitamins you need. And quitting smoking remains the most effective way to avoid many cancers. There's no diet, or vitamin supplement, that could ever counter the toxic effects of cigarette smoke."