Do Blood Transfusions Really Slow Aging? Discover the Science Behind It

Highlights

• Dr. Greger reviews research suggesting that certain age-driving factors like possibly malfunctioning protein building blocks (peptides) can be filtered out of blood to rejuvenate tissues and improve cognition in rodents.
• Researchers applied a technique called plasma exchange therapy, which replaces blood plasma with fresh saline, to Alzheimer’s patients who then experienced 60% less cognitive decline.

Dr. Michael Greger, an American physician, author, and speaker, reviews research exploring whether blood transfusions can rejuvenate tissues to make us younger in a NutritionFacts podcast. The main questions regarding the potential of blood transfusion therapies to rejuvenate organ function are how they work and relatedly, which transfusion technique is most effective. In that sense, researchers have questioned whether blood from younger animals contains an element that works against aging or if blood from older ones contains debilitating factors that drive aging. His report suggests that age-driving factors in older blood, such as malfunctioning peptides, contribute to aging and can be filtered out to rejuvenate aged individuals’ tissues.

Evidence for this comes from a study of patients with moderate Alzheimer’s disease who experienced substantially slower cognitive decline after undergoing plasma exchange therapy. Plasma exchange therapy is a procedure where an individual donates blood and has the plasma replaced with saline — a mix of salt and water — and new albumin (a blood protein). The blood cells along with the new saline and albumin are then infused back into the patient. Eliminating certain plasma factors with this technique appears to slow cognitive decline in patients with Azlheimer’s. This suggests that some sort of factors in the blood like peptides and perhaps other unidentified blood elements contribute to age-related diseases like Alzheimer’s.

Historical Background On Using Blood Transfusions to Slow Aging

In his podcast, Dr. Greger explores research on whether revitalizing aged animal blood with blood from younger animals can slow aging. To begin, he relays data from a study where researchers sought to find if there are critical, rejuvenating elements that are circulating in the bloodstream of youthful animals. To test this, old muscle stem cells were grown (cultured) in blood from young animals. This had a rejuvenating effect on the cells, suggesting that young blood may contain vitalizing factors that we lose with age. Alternatively, it could also mean that a repair-repressing component builds up with age, which the young blood diluted in the study.

To find the extent that circulating factors play a role in aging, researchers also turned to another procedure called heterochronic parabiosis — where the circulatory systems of a young and old animal are surgically joined. Along these lines, a study of heterochronic parabiosis, where an old rat was coupled with a young rat, showed that older rats lived about 20% longer. Subsequent experiments showed that older rats coupled to younger rats also became stronger and had better cognition, and tissues like the brain, heart, and muscles were rejuvenated.

Dr. Michael Greger continues, saying this did not necessarily mean that aging was slowed. Rather, having the use of youthful organs from younger animals could have contributed to a longer lifespan and rejuvenated organs. To find out whether there are transmissible, bloodborne factors that work against aging when animals’ circulatory systems are coupled, researchers tested what transfusing blood from younger animals into older ones would do.

Blood Transfusions from Young Donors and Plasma Exchange Therapy

Infusing the blood of young mice into older ones has been shown to have rejuvenating effects on multiple organs, similar to heterochronic parabiosis. This has led to ongoing clinical trials testing whether weekly infusions of blood products from young donors into patients with Alzheimer’s disease improves cognition.

We are still left with the question, though, of whether young blood contains restorative factors or whether blood from older animals contains debilitating aging factors. To address this issue, another team of researchers diluted the blood of old mice by siphoning off the plasma and replacing it with water. If the rejuvenating effects of heterochronic parabiosis on older animals were due to some anti-aging factor in young blood, then nothing should have happened. Conversely, if blood from older animals contains an age-driving factor that gets diluted with water, then plasma dilution would work just as well as heterochronic parabiosis.

Intriguingly, replacing plasma with water did work just as well as heterochronic parabiosis for the mice. As such, young blood transfusion worked just as well as heterochronic parabiosis in rejuvenating the liver. Moreover, young blood transfusions rejuvenated the muscle and brain even better than heterochronic parabiosis. This suggested that most, if not all, of the rejuvenation benefits of heterochronic parabiosis could be replicated with blood dilution.

Dr. Greger says this was good news, because there is already an FDA-approved technique in use today for this purpose — plasma exchange therapy. This procedure is usually used to filter out toxins but whether it could be used for tissue rejuvenation had not been tested.

Given the findings from diluting the plasma of old mice, researchers tested plasma exchange therapy’s effects on patients with Alzheimer’s disease since plasma exchange is a similar technique. While the procedure did not seem to help those with mild Alzheimer’s disease, those with moderate Alzheimer’s disease experienced about 60% less cognitive decline over the course of 14 months. This finding is in stark contrast with typical Alzheimer’s treatments like memantine that helps with symptoms but does not change the course of cognitive decline.

Exploring Plasma Exchange Therapy for Multi-Tissue Rejuvenation

From heterochronic parabiosis to plasma exchange therapy, the research suggests that diluting age-inducing factors from the blood of older animals, including humans, may serve to rejuvenate tissues and organs. In that sense, the finding that plasma exchange therapy substantially lessens cognitive decline in Alzheimer’s patients may only be the tip of the iceberg.

Along these lines, questions remain regarding whether plasma exchange therapy in older individuals could rejuvenate other organs like the liver, kidney, and heart. Not only that but whether plasma exchange therapy may help with other age-related diseases or be used to rejuvenate tissues and organs during natural aging needs testing with further human trials.