In brief: Fasting 'can revive immune system'

PHOTO: In brief: Fasting 'can revive immune system'

While chemotherapy can save lives, it can also cause many side effects, including the depletion of immune cells.

Chemotherapy aside, even normal ageing takes a heavy toll on the immune system.

Researchers, reporting in Cell Press journal Cell Stem Cell, have found that periodic fasting may combat both chemotherapy-induced and ageing-related changes in immune cell function by replenishing stem cells in the blood. The findings suggest that fasting may provide benefits for cancer patients, the elderly and people with various immune defects.

It is estimated that more than one-fifth of cancer-related deaths are hastened, or even caused, by the toxic effects of chemotherapy rather than the cancer itself. And there are currently no interventions to lessen the side effects that chemotherapy has on the immune system, or to prevent the immune cell dysfunction that occurs with ageing, said Cell Press in a statement.

Previous work by University of Southern California researchers found that temporary nutrient restriction could increase stem cells' resistance to certain stressors.

In their latest work, they showed that prolonged fasting periods cause a major reduction in white blood cell number, which is replenished when feeding starts again.

This effect is able to switch stem cells to a mode able to not only regenerate immune cells and reverse the immunosuppression caused by chemotherapy, but also rejuvenate the immune system of old mice, the researchers found.

The protection against white blood cell loss also occurred in human patients who fasted for a single 72-hour period before chemotherapy

This article was first published on June 8, 2014.
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