Cancer cells can be destroyed by using injections of vitamin C, research has shown.
Usually the body keeps a tight rein on vitamin C levels in the blood. But scientists found that the mechanism can be by-passed if the vitamin is injected straight into the bloodstream instead of passing through the digestive system.
Experiments showed that high levels of vitamin C in the blood generate hydrogen peroxide, which is lethal to tumours.
The chemical forms in the spaces between cancer cells, damaging membranes, upsetting metabolism, and scrambling DNA, according to the research published in the journal Proceedings of the National Academy of Sciences.
The use of high dose vitamin C as a complementary or alternative cancer treatment has a long history dating back to the 1970s.
Patients have taken the vitamin both by mouth and intravenously. But despite some positive outcomes, reliable evidence that the therapy works has been lacking.
For this reason claims that vitamin C can treat cancer have been dismissed by conventional cancer experts.
The investigation led by Dr Qi Chen, from the National Institutes of Health in the US, found the therapy halved the growth of aggressive tumours in mice, killing cancer cells while leaving healthy tissue unharmed.