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Are “blood boys” like the one on Silicon Valley a real thing, and if so do they work? – D.L. Madison, WI

Yes! They totally are! Well, sort of – here’s the skinny:

The idea of using the blood of younger people to heal or slow the aging process has been around for a while. There has been a recent resurgence in interest for two reasons. First, some intriguing new data has been generated and widely publicized, and second, some folks in Silicon Valley (the place, not the show) may actually be trying it.

The data has come from “heterochronic parabiosis” experiments in mice. Heterochronic parabiosis is the surgical pairing of the circulatory systems of two animals of different ages. Importantly, these experiments are performed in an attempt to understand the role of blood (and the factors it contains) versus the cells in the aging process – not in an attempt to develop a treatment for aging. Studies have shown that the cells in older mice benefit from being exposed to the blood of younger animals.  That sounds great! However, there are some caveats. First, these mice are usually surgically connected for weeks to months of time – these effects have never been shown with a single or even multiple infusions – only continuous parabiosis. Second, the younger animals experience negative effects (their cells act like they are older), so it’s not something anyone is likely to sign up for.

In typical pseudo-scientific fashion, some took this work as “proof” that the blood of the young can reverse the aging process.  Peter Thiel, in particular has expressed interest in this, and there are rumors he actually engages in the practice. Sillicon Valley (the show) is likely poking fun at Thiel, a famous Sillicon Valley (the place) venture capitalist whose fotune came from being one one of the original investors in Facebook.

Now is the time that we tell you that there is no evidence of any health benefits in humans. A recently formed company (Ambrosia, LLC) is testing the transfusion of younger peoples blood in a “clinical trial”. However, I put the words “clinical trial” in quotations there because this is a paid trial (patients pay to join), and there is no control group (non-young blood infused patients), so the trial isn’t testing whether these infusions reverse or slow the aging process – they are really just testing the hypothesis that people are willing to pay $8,000 for the blood of younger people. It looks like the answer is “yes”, which is kinda terrifying.

Of course, blood transfusions are very useful in some situations. They are primarily used to replace lost blood in people who have suffered accidents, had surgeries, or have abnormal oxygen-carrying red blood cell physiology. More nefariously, some endurance athletes use blood transfusions as a form of “blood doping” to increase the number of red blood cells in their blood. This is effective because more red blood cells means you can carry more oxygen, and it was one of several ways that Lance Armstrong famously cheated during his Tour de France wins.

So, yes, DL, there are some “blood boys” (and probably “blood girls” and blood non-binary folks) out there. No, it doesn’t reverse, stop, or even slow the aging process. You can’t reverse the aging process (at least not currently), but aging is better than the alternative.