Fasting Before Chemo Protects Healthy Cells

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This protected the healthy cells against exposure to toxic compounds, while leaving cancer cells unprotected.

In turn, the researchers then tested mice injected with brain cancer cells to see how they faired upon exposure to a high dose of the chemo drug etoposide. Noting that just one-third of this amount is considered to be the maximum for what is allowable for human treatment, Longo and his team compared results among mice starved for 48 hours and 60 hours pre-treatment with mice that were not starved.

While 43 percent of the non-starved mice died within 10 days of treatment, only one of the 48-hour starved mice died in that time. As well, while starved mice had lost 20 percent of their weight before treatment, most regained it back within four days of chemo exposure while the non-starved mice actually lost 20 percent of their weight post-treatment.

Non-starved mice also suffered toxic side effects, such as impaired movement, ruffled hair and poor posture. The 48-hour starved mice displayed no such problems.

Mice starved for 60 hours were exposed to even higher chemo doses. At that level, all non-starved mice died by the fifth day, at which point all the starved mice continued to survive. Again, almost all starvation weight loss was regained post treatment, and no signs of toxicity were evident.

Longo and his colleagues concluded that short-term starvation does appear to guard healthy cells and allow cancer treatment to attack only diseased cells. They said they are now organizing a human trial.

"We hope this works with patients, and we have reason to think it will," he said. "I think I'm more enthusiastic about this than anything else I've done. And you can see the potential for this being turned into something very, very useful. But we won't know until we do it."

Dwayne Stupack, an assistant professor of pathology with the Moores Cancer Center at the University of California, San Diego, described the current effort as a "reasonable" approach toward mitigating the undesirable effects of chemotherapy.