Young Blood as a Treatment for Age-Related Diseases

The past decade has seen groundbreaking research in the field of aging, revealing a fascinating phenomenon:
blood transfusion from young mice to old mice showed a significant slowdown in the aging rate.
This discovery sparked great interest and led to a search for a modern "fountain of youth," in the form of treatments based on young blood transfusion.

The scientific basis for the idea rests on parabiosis experiments, a method in which the circulatory systems of two animals are connected. Already in early studies, and later in the work of researchers like Amy Conboy and Tony Wyss-Coray, it was observed that when an old mouse shares a bloodstream with a young mouse, there is an improvement in the muscle, liver, and brain function of the old mouse.
It is important to emphasize: the effect in these models may stem not only from "young factors" in the young blood, but also from the dilution of harmful factors that accumulate in the old blood with age. That is, it is possible that part of the benefit comes from removing substances rather than adding them.

In 2017, the startup company Ambrosia caused a stir in the medical world
when it began offering experimental treatments of young plasma transfusion (the liquid part of the blood) at a price of $8,000 per liter.
The treatment was based on the assumption that components in young blood can stimulate biological processes in the body and slow down aging.

However, the "fountain of youth" approach also raised many concerns.
The lack of established clinical trials in humans raised questions about the safety and efficacy of the treatment.
Additionally, ethical questions arose regarding an approach that could turn aging into a "privilege" of the wealthy.

In February 2019, a severe blow came to Ambrosia and the idea of young blood transfusion.
The U.S. Food and Drug Administration (FDA) issued a sharp statement, on behalf of Commissioner Scott Gottlieb and Director Peter Marks, stating that there is no clinical evidence for the efficacy of young plasma transfusion against age-related diseases, dementia, Alzheimer's, heart disease, or Parkinson's.

The authority emphasized that this is not just an unproven treatment, but a treatment that may be dangerous: plasma transfusion carries a risk of allergic reactions, fluid overload on the circulatory and cardiac system, acute lung injury related to transfusion, and exposure to infectious diseases. The FDA explicitly warned the public not to consider these treatments safe or effective.

Following the statement, Ambrosia stopped the treatments in February 2019 to comply with FDA guidelines. However, the treatment was not completely shelved: the company's founder, Jesse Karmazin, shortly after returned to offering plasma transfusions in an "off-label" format under a new brand called Ivy Plasma, and later even resumed using the name Ambrosia. The story illustrates how wide the gap remains between marketing promises and scientific evidence in this field.

References:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6764071/