According to a new study published in Proceedings of the National Academy of Sciences, fasting a few days before chemotherapy treatments may protect patients from debilitating side effects from the treatments such as hair loss, nausea and anemia. It could also allow the use of more potent chemotherapy doses without endangering patients.

The healthy cells deprived of nourishment stop dividing and become more resistant to stress. This makes them less vulnerable to chemotherapy, which targets cells that are dividing. Because cancer cells do not respond to their environment the same way, starvation does not protect them from the drugs.

The scientists report that starving mice for a few days before chemotherapy treatments protected their healthy cells from damaging side effects. Of the 28 mice that received only water for 48 to 60 hours before chemotherapy only one died from the treatment while 20 of the 37 mice that did not fast died. Fasting mice suffered no visible treatment side effects, compared with the non-fasting mice which became sluggish and developed ruffled hair.

Researchers are planning a trial that will begin this year to study the benefits of fasting in cancer patients taking chemotherapy drugs. They remind cancer patients that they should not fast before treatment without consulting their doctor as it may be harmful to them.