A new study is suggesting that short-term fasting could help protect cancer patients against the effects of chemotherapy.
Scientists from the University of Southern California have found in experiments with mice that fasting strengthens healthy cells but not cancer cells, and they are optimistic such strategies could be employed to improve cancer treatment.
Chemotherapy has many side-effects because the drugs also kill healthy body cells and scientists have long been searching for ways to improve the body's defences against the drugs because one of the many side-effects of chemotherapy is that the powerful drugs also kill healthy body cells.
The researchers led by Dr. Valter Longo, found that a short period of fasting deprived healthy cells of oxygen, causing them to enter an emergency mode that made them highly resistant to stress.
But this did not apply to cancer cells and when they were deprived of oxygen they became more vulnerable to drugs than the normal cells.
This means in theory that more powerful and effective doses of cancer treatment could be used without harming patients.
While the researchers say the next stage will be to test the results in humans, they warn cancer patients not to try starving themselves.
For the research mice injected with aggressive human tumours and then given a potentially lethal dose of chemotherapy after two days of fasting, survived whereas half of the control mice, which had not fasted, died.
The different resistance of normal human and human cancer cells to chemotherapy after a short period of starvation has already been confirmed in the laboratory.
In a future trial the researchers will examine whether a 48 hour starvation period is sufficient to generate protection, without the risk of making a patient too weak and even more sensitive to chemotherapy.
The research is published online in the current issue of the Proceedings of the National Academy of Sciences.