It’s not even October yet, but vampires are already the talk of the town. Earlier this month, longevity researchers published a review of ongoing projects focused on increasing human lifespan via animal models. That review resulted in an unintended consequence—a cascade of popular news reports about the benefits of “drinking young blood.” So is vampirism really the new longevity frontier?
Will the Real Longevity Scientists Please Stand Up?
Let’s be frank. The review has absolutely nothing to do with human blood transfusions or the ingestion of bodily fluids. The piece was published in the journal Nature under the title, “Facing Up to the Global Challenges of Aging,” authored by Linda Partridge, Joris Deelen, and P. Eline Slagboom. That title doesn’t exactly evoke images of dark capes, tall collars, and a Hungarian accent. So what inspired the subsequent rally towards vampirism?
The short answer? Mice.
The review referenced a couple of animal trials in which blood played a major role. In these instances, mixing young mouse blood into older mice reduced age-related illnesses and chronic conditions. The review touched on two studies about these bloody issues: one that conjoined the blood system of younger and older mice (a process called parabiosis), and one that transferred plasma from human umbilical cords into mice to improve their brain function.
Parabiosis: Stitching Together Frankenstein’s Mouse
Literally translated, parabiosis means “living beside.” In experimental physiology, parabiosis refers to surgically combining the physiological systems of two organisms. Imagine a direct blood transfusion in which a donor’s blood goes into recipient and the recipient’s blood goes back into the donor in an endless loop.
In the mid-2000s, Stanford University researchers used parabiosis to study the process of aging. To do so, they surgically joined two mice so that they developed a common circulatory system. This encouraged the rapid and continuous exchange of cells and soluble factors between the organisms. The “young blood cures aging” idea was born.
The Stanford researchers found that parabiosis with young mice significantly enhanced the regeneration of muscle and liver cells in older partners. In other words, elements in the younger mouse’s blood seemed to kick start the stalled healing capabilities of its aging symbiotic partner.
Following suit, other researchers aimed to pinpoint which specific proteins in younger blood create a more robust environment for cellular function. This research inspired start-ups like Ambrosia, a company that offers transfusions of teenage blood plasma to customers at a cost of over $8,000.
And just a friendly reminder: researchers have been studying parabiosis for at least the past 150 years. A clear connection between these animal models and the feasibility of using such findings for human benefits remains to be seen.
Of Mice, Men, and a Thirst for Blood
One study, however, did cross the mouse-human boundary. The only other reference from Partridge’s article that even somewhat relates to vampirism comes from a study on the effects of umbilical cord plasma on the brains of mice.
In this study, Stanford researchers created plasma pools from umbilical cords, young adult, and elderly donors. Then, they injected the plasma intravenously into aged mice. They found that plasma from younger donors rejuvenated hippocampal function in the older brains. The hippocampus is the brain region that plays a critical part in memory.
This study, along with others, attempted to discover what parts of the blood specifically helped aging cells to regenerate. These conversations have never been about drinking blood—and they’re rarely about blood transfusions either.
As Partridge and her team clearly state in their review, “The practical accessibility of both the human microbiome and blood system makes therapeutic manipulation a particularly attractive approach, but research in animals is needed to establish the long-term consequences and possible side effects.”
We don’t really know why or how some of these experiments work and others don’t. Some studies have even shown the exact opposite results—even in mouse models. Sometimes, young blood (or its components) gives rise to detrimental effects that range from mild allergic reactions to fatal responses.
The Stakes of Young Blood Research
There’s no professional research to suggest, in good faith, that blood transfusion is a means for alleviating age-related health problems. Moreover, there’s no data whatsoever to support the benefits of ingesting human blood—in case you were tempted by the idea.
This isn’t to say that young blood doesn’t hold promise for future longevity research. The advantage of giving young blood to an older person is that it may contain different rejuvenating factors. And these factors could have beneficial effects on many diseased organs at the same time. Furthermore, the transfusion of whole blood or its components is a safe clinical practice today. It already has many applications in regenerative medicine. We just don’t know if and how those applications translate to human subjects or human aging.
So here’s our friendly public service announcement: It is now safe to put your garlic and wooden stakes back in storage until Halloween.