Huge doses of vitamin C found to boost cancer treatment
It may sound like the kind of science that would raise eyebrows rather than scientific interest but recent research has found that raised levels of vitamin C alongside cancer treatment could aid the body to kill the cancerous cells. The levels of vitamin C are not possible through eating a few oranges a day, as those administered to patients were in infusions of 800 to 1,000 times the recommended daily dose – you would need to eat a thousand oranges per day to reach such levels.
The researchers at the University of Iowa were keen to determine whether high doses of patients were tolerable and safe in patients being treated for cancer. Vitamin C was introduced three times a week for nearly two months and patients receiving the doses did not report any adverse events as a result.
Beyond being safe, however, the researchers noticed some remarkable results in those undergoing cancer treatments. In a small group of 14 patients suffering from non-small cell lung cancer, 93% of those patients responded to treatment that compares with 40% as the usual rate of response. Of this 93%, 30% showed signs that their tumours were reduced in size.
The main aim of the trial was to determine safety and the results were positive; patients did not report serious adverse events, with the most serious cases being infrequently observed high blood pressure spike following infusion. Other than this, there were side effects that included frequent urination and dry mouth.
At the moment, there is a certain degree of speculation as to why vitamin C produces these improved results in cancer cells – it is thought that, even in high doses, vitamin C is not toxic to healthy cells. It is considered that the impacts are only felt in tumour cells as a result of the high levels of iron in tumour cells, which then reacts with vitamin C to form hydrogen peroxide – effectively killing off the tumour cell in a targeted way.
"This is a significant example of how knowing details of potential mechanisms and the basic science of redox active compounds in cancer versus normal cells can be leveraged clinically in cancer therapy," says co-senior author Douglas Spitz. "Here, we verified convincingly that increased redox active metal ions in cancer cells were responsible for this differential sensitivity of cancer versus normal cells to very high doses of vitamin C."
The research is currently going through Phase 2 trials and the full understanding of how beneficial the vitamin C doses will be better determined once these complete.
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