A new study has discovered that chemotherapy drugs work better when combined with cycles of short, severe fasting.
Scientists from the University of Southern California, US, found that even fasting alone effectively treated a majority of cancers tested in animals, including cancers from human cells.
The study, published in Science Translational Medicine, found that five out of eight cancer types in mice responded to fasting alone.
The authors report that “just as with chemotherapy, fasting slowed the growth and spread of tumours.”
They write: “The combination of fasting cycles plus chemotherapy was either more or much more effective than chemo alone”.
According to senior author Professor Valter Longo, Professor of Gerontology and Biological Sciences at the University of Southern California, no mice survived in either case if treated only with chemotherapy.
Only a clinical trial lasting several years can demonstrate whether humans would benefit from the same treatment, Prof Longo cautioned.
He said that results from the first phase of a US trial with breast, urinary tract and ovarian cancer patients, on which he is collaborating with the US National Institute on Ageing, have been submitted for presentation at the annual meeting of the American Society of Cancer Oncologists (ASCO) this summer.
“We don’t know whether in humans it’s effective,” Prof Longo said of fasting as a cancer therapy.
“It should be off limits to patients, but a patient should be able to go to their oncologist and say, ‘What about fasting with chemotherapy or without if chemotherapy was not recommended or considered?’”
Prof Longo stated that fasting may not be safe for everyone.
The clinical trial to be reported at ASCO did not enroll patients who already had lost more than 10 per cent of their normal weight or who had other risk factors, such as diabetes.
“What we have learned from (previous) trials is that during fasting, while normal cells deprived of nutrients enter a dormant state similar to hibernation, cancer cells try to make new proteins and take other steps to keep growing and dividing.”
The result, Prof Longo said, is a “cascade of events” that leads to the creation of damaging free radical molecules, which breaks down the cancer cells’ own DNA and causes their destruction.
“The cell is, in fact, committing cellular suicide. What we’re seeing is that the cancer cell tries to compensate for the lack of all these things missing in the blood after fasting. It may be trying to replace them, but it can’t,” Prof Longo explained.
ASCO takes place this year in Chicago, US from June 1-5.
Image courtesy of curtfleenor, Flickr Creative Commons
