Could a pill one day slow ageing in humans?Punchstock Rapamycin, a drug commonly used in humans to prevent transplanted organs from being rejected, has been found to extend the lives of mice by up to 14% — even when given to the mice late in life. In flies and worms, drug treatments have been shown to prolong lifespan, but until now, the only robust way to extend life in mammals has been to heavily restrict diet. The researchers caution, however, that using this drug to extend the lifespan of humans might be problematic because it suppresses the immune system —...