Growth hormone, insulin may be key to longevity
By Megan Rauscher

NEW YORK (Reuters Health) - A number of studies have shown that restricting calories increases the lifespan of animals, but the biological basis for this has remained elusive. A new report hints that growth hormone, as well as insulin, are key factors in the life-extending effects of calorie restriction.

"The implication ... for pharmaceutical development would be that the signaling pathways of growth hormone and insulin may be logical targets for development of anti-aging medicine," Dr. Andrezej Bartke from Southern Illinois University in Springfield told Reuters Health.

"Although it would be irresponsible to recommend that healthy people start using anti-diabetic drugs," said Bartke, "it is reasonable to suggest that treatment(s) causing an improvement in insulin sensitivity combined with modest reduction in insulin release would reduce risk of age-related disease and likely also delay aging."

Bartke's team tested whether growth hormone and insulin are tied to the life-extending effects of calorie restriction in a series of experiments with normal mice and mutant mice deficient in growth hormone. the rest