Fasting May Improve Cancer Treatment

Cancers slow or stop spreading when fasting combined with chemotherapy

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Dietary guidelines are constantly changing. And doctors rarely discuss eating plans with their patients being treated for cancer. A new study shows that eating nothing at all from time to time could be extremely beneficial.

Studies have found that fasting alone was an effective treatment for the majority of cancers tested in animals and human cancer cells. When short cycles of severe fasting were combined with chemotherapy, the results were impressive.

"Ask your oncologist if fasting is safe and possibly beneficial for you."

These are the findings of studies being carried out under the direction of Valter Longo, Ph.D., professor of gerontology and biological sciences at the University of Southern California.

Published in February, 2012 issue of Science Translational Medicine, researchers discovered that five out of eight types of cancers in mice responded to fasting alone. That is, the growth and spread of cancer slowed after the mice were deprived of food.

Senior study author Longo, said that without exception, "the combination of fasting cycles plus chemotherapy was either more or much more effective than chemo alone."

The results showed:

  • Multiple fasting cycles when combined with chemo, cured one-fifth of the mice that had a highly aggressive children's cancer that had metastasized throughout the body.
  • The same results were seen in 40 percent of mice with the same cancer that hadn't metastasized as widely.
  • In comparison, no mice survived with the same cancers when treated with chemotherapy alone.
  • The combination of fasting and chemo slowed the growth of breast cancer, melanoma, glioma and human neuroblastoma.
  • Several cases showed fasting cycles to be as effective as chemotherapy.
  • Mice that had human ovarian cancer lived longer after fasting.
  • In all cases, fasting plus chemo resulted in the mice living longer, a slowing of tumor growth and/or a limiting of the cancer spread. 

And as exciting as this sounds, only a multi-year clinical trial could evaluate whether or not humans could benefit similarly, cautioned Longo, who added that fasting isn't safe for all patients.

"We don't know whether in humans it's effective," 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?"

In a 2010 study published in Aging, 10 patients said that fasting seemed to reduce the number of chemotherapy side effects.

"A way to beat cancer cells may not be to try to find drugs that kill them specifically but to confuse them by generating extreme environments, such as fasting that only normal cells can quickly respond to," Longo said.

Shannon Cox, M.D., a cancer specialist at Austin Cancer Centers in Austin, Texas, tells dailyRx that he's unfamiliar with this theory. "This is brand new to me, but very interesting!" Dr. Cox said.

This research was funded by the National Institutes of Health, the Bakewell Foundation, The V Foundation for Cancer Research, the Norris cancer center, the Italian Association for Cancer Research and the Italian Foundation for Cancer Research.

Reviewed by: 
Review Date: 
February 8, 2012
Last Updated:
February 8, 2012