Short-term starvation techniques may help shield healthy cells from the damaging side effects of chemotherapy, while still leaving tumor cells vulnerable to treatment, researchers said.

A series of laboratory experiments in yeast, mice and human cells found that reducing the food supply for as long as 60 hours helped toughen normal cells and make chemotherapy work better on tumors, researchers said today in the Proceedings of the National Academy of Sciences.

Scientists have known that limiting calorie consumption can help mice and other organisms live longer and avoid developing tumors. The new research suggests calorie restriction may also enhance chemotherapy for cancer patients. About 1.4 million people in the U.S. will be diagnosed with the disease this year, according to the American Cancer Society.

``The potential here is that you could give chemotherapy three times more frequently with very little side effects,'' said Valter Longo, a gerontologist at the University of Southern California, in a telephone interview. Longo was the study's senior author.

The experiments looked at how healthy cells and tumors responded to being deprived of glucose, a simple sugar. When yeast cells were genetically modified to be protected from toxins and were cut off from a glucose broth, they were 1,000 times better protected against damage from oxygen or chemotherapy drugs than yeast cells with an amplified tumor gene. - See Starving Protects Healthy Cells From Chemotherapy, Study Says for the complete report.