London: Fasting for short periods could help combat cancer and boost effectiveness of the treatments, a new study has claimed.
Researchers at University of Southern California found that fasting slowed the growth and spread of tumours and cured some cancers when it was combined with chemotherapy.
It`s hoped that the findings will lead to the development of more effective treatment plans and further research is now under way, they said.
In experiments on mice, they found tumour cells responded differently to the stress of fasting compared to normal cells. Instead of entering a dormant state similar to hibernation, the cells kept growing and dividing, in the end destroying themselves, they said.
"The cell is, in fact, committing cellular suicide," lead study author Professor Valter Longo was quoted as saying by the Daily Mail.
"What we are 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 cannot."
For the study, published in the journal Science Translational Medicine, Prof Longo and his team looked at the impact fasting had on breast, urinary tract and ovarian cancers in mice.
Fasting without chemotherapy was shown to slow the growth of breast cancer, melanoma skin cancer, glioma brain cancer and neuroblastoma -- a cancer that forms in the nerve tissue
In every case, combining fasting with chemotherapy made the cancer treatment more effective, the researchers found.
Multiple cycles of fasting combined with chemotherapy cured 20 per cent of those with a highly aggressive form of cancer while 40 per cent with a limited spread of the same cancer were cured, they said.
But none of the mice survived if they were treated with chemotherapy alone, they added.
According to the researchers, they are already examining the effects of fasting on human patients, but only a clinical trial lasting several years will confirm if human cancer patients really can benefit from calorie restriction.
However, they highlight that fasting could be dangerous for patients who have already lost a lot of weight or are affected by other risk factors, such as diabetes.
Results of a preliminary clinical trial will be presented at the American Society of Cancer Oncologists conference to be held in Chicago in June.
Prof Longo said their study only tests if patients could tolerate short fasts of two days before and one day after chemotherapy.
"We don`t know whether in humans it`s effective.
"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."