Young mouse blood extends lives of older ones while rejuvenating them
Surgically attaching old mice to young mice to exchange their blood has previously been shown to rejuvenate the older individuals’ brains, livers and muscles. Now, it has been shown to also extend their lifespan, even after the animals have been detached
By Alice Klein
27 July 2023
The blood of a young individual may contain cells, proteins or other components that have rejuvenating properties
Alamy Stock Photo
Surgically attaching old mice to young mice for three months turns back the biological age of the older individuals and extends their lifespan after they are detached. The finding adds to a large body of research pointing to the restorative effects of young blood.
Several studies have found that sewing old and young mice together so their blood flows into each other’s bodies – a procedure called parabiosis – has rejuvenating effects on the older individual’s brain, liver and muscles. However, whether this means they end up living longer, even after separation from the young mice, has been unclear.
To find out, a team co-led by James White at Duke University in North Carolina and Vadim Gladyshev at Harvard University surgically connected old mice (aged 20 months) to either young mice (aged 3 months) or other old mice for a period of three months. The researchers then detached them and measured how long they lived. “We wanted to know, do the anti-ageing effects just go away after you take the mice apart?” says White.
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The old mice that had been joined to the young mice ended up living six weeks longer on average than those that had been joined to other old mice, a lifespan extension of about 5 per cent. “If you could improve human lifespan by 5 per cent, that could mean an extra four or five years,” says White. The researchers did not compare these mice’s lifespans against those that were not surgically attached to any other animal in case the procedure itself affected their longevity, which could blur the results.
However, this effect is smaller than that achieved by calorie restriction, which can make mice live up to 27 per cent longer.
