Recently, there have been a lot of articles going around that want to make us believe that the blood of younger people is some sort of anti-aging potion that can instantly make us look and feel younger and healthier than we actually are. The belief is that injecting young blood into your system may have all kinds of benefits. Some famous moguls, like Peter Thiel, have already expressed an interest in using this form of “medication” in order to improve their quality of life as they age. Even some companies have started working on treatments like these in order to fill this niche need of moguls around the world.
One thing that no one expected is that this whole belief may potentially be based on incorrect observations. The belief is that the young blood is rejuvenating, when in fact it may be that the blood of older people is actually toxic. Testing showed that injecting old mice with young blood had next to no benefits while injecting young mice with old blood almost instantly worsened the young mice health. This tells us that some molecule in the blood of older mice is causing the blood to become toxic. The accumulation of these molecules negatively affects not only the bloodstream but other organs and fluids within the body, causing overall deterioration of health.
So sadly, young blood is not the medicine we all thought it was and does not have any anti-aging properties as previously believed. The reason people thought it did in the first place came as a result of a study performed in 2005. During this study scientists connected surgically connected two mice, one older and one younger. This process is called parabiosis and it forces blood and other fluids to course freely through the bodies of the two mice. Pretty soon into the study, scientists noticed that tissue repair in the older mice became much quicker. The media immediately focused on the part of this process that was the easiest to explain, and that was the exchange of blood between the two mice. But further research showed that there was far more to it than that. In fact, the blood was the least important part of the whole transaction. What is far more important is that the older mouse gained access to the organs of the younger mouse. Access to younger kidneys and lungs was especially beneficial. This access benefited the older mouse much more than anything else.
During a newer study, scientist only focused on exchanging blood between the mice. They split the blood reserves almost in half and exchanged them between the mice. After a month they performed extensive tests on both mice. The older mouse showed almost no improvement whatsoever, while the younger mouse showed a severe decline in health. Each of the systems within the body declined in some way. Brain cell development suffered the most. So to sum up, there was no benefit from using young blood, but using the blood of older mice was highly detrimental.
So why is the old blood so bad? Scientists believe that it is due to a yet unidentified molecule that accumulates in the blood of older people/mice. These molecules then inhibit the growth and development of new cells. This also tells us that those molecules are also stronger than the ones found in young blood. One way that scientists may potentially slow down aging is to target those molecules, but still, a lot of research needs to be done before this happens.