Vit C injection may treat cancer
2008-08-05 08:29
Washington - Vitamin C might be
useful to treat cancer after all, according to a US study
published on Monday in which injections of high doses of it
greatly reduced the rate of tumour growth in mice.
The idea that vitamin C, also known as ascorbic acid, could
be used to treat cancer was advanced in the 1970s by American
scientist Linus Pauling, who awarded the Nobel Prize in
chemistry in 1954.
The notion was controversial and subsequent studies failed
to show a benefit. But those studies involved vitamin C given
orally.
The new study by researchers at the US government's
National Institutes of Health involved injections of vitamin C
to enable greater concentrations of it to get into the system.
The researchers implanted three types of aggressive cancer
cells into laboratory mice - ovarian, pancreatic and
glioblastoma brain tumours.
Mice that were given high-dosage
injections of vitamin C experienced tumour growth only about
half that of similar mice that were not given the injections,
they said.
Treating some cancers
"The key finding here is that this is ascorbic acid used as
a drug and it appears to have some promise in treating some
cancers," Dr Mark Levine of the NIH's National Institute of
Diabetes and Digestive and Kidney Diseases, who led the study,
said in a telephone interview.
The researchers believe the elevated amounts of ascorbic
acid generate hydrogen peroxide in the body that acts against
the cancer cells.
"That hydrogen peroxide leads to death of some cancer cells
and does not seem to kill normal cells. Why that is, we don't
know," said Levine, whose team's findings were published in the
Proceedings of the National Academy of Sciences.
Levine said a recent clinical study in Canada in which he
was involved showed that similar high doses of vitamin C can be
injected into people with very minimal side effects.
"The thing that's realistic here is that the concentrations
that are effective, or similar concentrations, can be achieved
in humans," Levine said.
A reasonable next step would be to begin studies testing
whether this works in people, he said. "I think we're pretty
close to being ready to do that," Levine said.