The blood of the young can slow down the ageing process, accelerate healing and even treat degenerative brain disorders. That’s not the plot of a sci-fi novel, it’s the result of new research by degeneration expert Dr Tony Wyss-Coray at Stanford University. Though to be clear, he’s only experimented on mice so far. “We discovered that circulatory factors in the blood of young mice are sufficient to slow or reverse behavioural deficits and other signs of brain ageing in old mice,” he says.
In other words, old mice that share a blood supply with young mice are rejuvenated: their brains, muscles, pancreases, livers and hearts start behaving like those of a younger mouse. The discovery originally came about when Wyss-Coray was trying to find a protein biomarker for Alzheimer’s disease. “We noticed that the biggest changes in dozens of measured proteins occurred with ageing rather than with disease,” he says.
His colleague Dr Tom Rando had previously shown that young blood can rejuvenate old muscle stem cells, so Wyss-Coray decided to see if the brain would benefit from the same process. It did. In maze testing, older mice that had been injected with plasma from young mice performed as if they were half their age. When their brain tissue was examined, the team discovered that the exposure to young blood had strengthened connections between neurons that normally weaken with age.
But can the results be recreated in humans? “We are planning to treat 18 patients with mild to moderate Alzheimer’s disease and hope to finish recruitment this year,” says Wyss-Coray. “Once the trial concludes we will analyse the data. There are no results before then.”
Elsewhere, a worrying market has begun to emerge in blood plasma. “I strongly believe in clinical trials and think there should be no treatments done without a positive phase 3 clinical trial result,” he adds. “Until then, I feel nobody should really pay for plasma infusions.” But even if it does work, there are probably limits to the effect. “Biological systems are too complex to be maintained and regenerated indefinitely,” says Wyss-Coray. “Even if our findings can be translated to humans, I think we will only have limited effect on some, but not all, aspects of ageing.”