Be careful about going to the O2 cinema in Greenwich, London, this February: you might come across some horrors. There’s “the long and winding road of arterial stiffness”, for one thing, or “extracellular matrix degradation in extrinsic ageing”. No one wants to see “the ‘hidden’ epidemic of adult Alzheimer’s and neurological deaths” or “the ageing eye”. No one except the delegates at the 2015 Ageing Summit, that is.
It’s shocking what happens to the body as we get older. Ageing is a natural process but we don’t have to accept it – and we haven’t. Science has addressed nutritional issues and the causes of disease and decrepitude so successfully that life expectancy in the developed world has doubled in the past 200 years. But this was low-hanging fruit. Many questions remain. How far are we willing to go to beat ageing? What do we think, for instance, about blood-sharing rodents?
In a few labs across the world, there are mice that exist in pairs. Each has had an incision cut in its side, and the pairs have been stitched together in such a way that the healing process leaves them conjoined. Blood vessels grow between them and within a fortnight the mice are pumping each other’s blood. Researchers are performing these nightmarish experiments because they offer a possible means to curing disease and reversing processes associated with ageing. And, of course, because they can.
Scientists have been doing this kind of thing for a long time. Read Samuel Pepys’s diary and you will find a discussion of related experiments carried out at the Royal Society in the 1660s. A group of researchers who included Robert Hooke and Christopher Wren would regularly transfuse blood between dogs, using a quill as a cannula, to see if the transfusion altered behaviour or physical features. Pepys suggested that they extend the technique, with “the blood of a Quaker to be let into an archbishop” in order to calm religious tensions.
Such research has gone in and out of fashion but it’s back in again today because the modern experiments, which pair old rodents with young ones, are producing fascinating results. Researchers have observed older mice being rejuvenated by blood from their younger partner. The reintroduction of chemicals that had long disappeared from the older body leads to new stem-cell activity: the cells begin to divide again, endowing the older mouse with new and vigorous muscle and liver tissue.
We have also seen increased neural growth in the older mice, early signs that exposure to young blood could rejuvenate the brain. That is why a group of elderly people are now receiving a weekly injection of blood plasma taken from healthy men under 30. Later this year, we should learn whether this regime has helped restore some brain function to the recipients, who are all Alzheimer’s sufferers.
Can we ever stave off decrepitude, ageing and death completely? That seems highly unlikely. Nonetheless, as delegates to the Ageing Summit will appreciate, it’s only natural to try. Evolution has equipped us with the ability to develop countermeasures to the failings it built into our bodies. Our evolved survival instinct makes us, as a species, put that ability to work.
Those paired-up mice have shown us that young blood reverses arterial stiffening, for example – we can go the other way down that long and winding road. So while bathing in the blood of young virgins is not an accepted route to new vigour, having it injected might be. One day, it may even be as commonplace as Botox. Whatever it takes, it’s clear that human beings won’t go down without a fight.