Injections of vitamin C can stop the spread of cancer and slow the growth of tumours by 50 per cent in tests on laboratory mice, scientists said yesterday.
The effect was seen on a variety of cancers, such as those of the brain, ovary and pancreas, although the researchers emphasised that further research was necessary before it can be tested on humans.
The idea that vitamin C, which is found in fruit and vegetables, could help to fight cancer goes back more than 30 years, but it fell out of favour when studies where the vitamin was given orally failed to live up to expectations.
But a US government-funded study, published in the journal Proceedings of the National Academy of Sciences, found that directly injecting high doses of vitamin C, or ascorbate, into the body can produce significant improvements in the health of mice with cancerous tumours.
Mark Levine of the US National Institute of Diabetes and Digestive and Kidney Diseases in Bethesda, Maryland, said that it was possible to raise ascorbate levels in the body to a point where they became pharmacologically active, which does not occur when the vitamin is taken orally.
But Dr Alison Ross of the charity Cancer Research UK said: "There is no evidence from clinical trials in humans that injecting or consuming vitamin C is an effective way to treat cancer. Some research even suggests that high doses of antioxidants can make cancer treatment less effective, reducing the benefits of radiotherapy and chemotherapy."