Research in the US has shown that injecting old mice with young blood leads to improved muscle strength, brain function and stamina; potentially reversing the effects of ageing.
3 studies were published last week in Science, all reporting on the rejuvenating effects of young blood in older mice. The young blood led to the appeared reversal of age-related declines in memory, learning, stamina and the function of many organs including the heart and brain.
Ageing is the underlying cause of a huge number of health problems. As our bodily systems slowly go into decline with age, health problems like dementia, cancer, heart disease and diabetes become more and more common. By learning more about the ageing process and its links with various health problems, we could predict, or even prevent many cases. Therefore, this research carried out in the US is of great importance.
In each study the researchers used a process called heterochronic parabiosis, which essentially involves joining two mice together; think conjoined twins. This process is carried out by making an incision on one side of each mouse and then allowing the wounds to heal in such a way that the two mice become joined. This process results in the joining of the two mice’s blood supply.
The researchers joined young mice (3 months) with older mice (18 months) and studied the effects of the new shared blood supply. They found that brain function increased in the older mouse, as not only did the mice grow more neural connections (how brain cells communicate), these connections were also stronger. This means better communication between the cells in the brain of the older mouse.
Villeda, lead author of one of the papers told the Guardian “There’s something about young blood that can literally reverse the impairments you see in the older brain.”
From these initial findings Villeda went on to directly inject older mice with young blood plasma (blood without red blood cells), and what he found was remarkable. He tested the young and old rats’ memory and ability to learn using a water maze and testing their ability to remember a threatening environment.
The old rats injected with young blood plasma performed just as well as the six-month old rats in the maze task. Even more remarkably, the older rats performed as well as the three-month olds in remembering a threatening environment.
These results suggest that there is something in the blood of young rats that is essentially reversing or halting the ageing process in older rats.. so what is it?
The answer to that very important questions is Creb; a protein that regulates the brain. The young blood plasma actually increases the activity of Creb which in turn switches on the genes that create neural connections.
However, young plasma isn’t just improving learning and memory in mice. Further studies have shown that injected young blood also increases blood flow in the brain by encouraging blood vessel growth. There was also an increase in the growth of neural stem cells which later become new brain cells. It has also been found that young blood makes older mice stronger and boosts endurance due to increased muscle function. The young blood also led to the older mice gaining a greater sense of smell.
So this is all very exciting, but what happens if you do the opposite, and inject young mice with old blood? Well, interestingly the younger mice show the opposite results; they show decreased brain and muscle function and perform less well in memory and learning tasks. So the process works both ways.
So what does this all mean for us? According to Villeda, “The evidence is strong enough now, in multiple tissues, that it’s warranted to try and apply this in humans”. This potential research is however, not expected to take place until three to five years from now.
This is all very promising, and if the same is found in humans there could be a dramatic reduction in the onset of age-related health issues, which would be particularly important as the aged population in the UK continues to grow. Preventing the onset of these diseases would save a huge amount of money and potentially work to prevent the potential impeding public health crisis.
However, we cannot know for sure the impacts of this study on humans until clinical trials are carried out. So don’t go stitching yourself to your children just yet.. there is plenty more we don’t know.