Parabiosis is a farfetched idea that might one day be an anti-aging treatment. But we have no idea yet.
Photo: Sipa France/AP
On Monday, Silicon Valley investor, Trump-supporter and reluctant mortal Peter Thiel had his not-so-secret anti-aging ambition revealed: He wants to buy the blood of the young. Journalist Jeff Bercovici at Inc. ran an interview with Thiel about medical breakthroughs, and in one of Thiel's answers, the notable eccentric billionaire said he was interested in "parabiosis stuff." Bercovici also found that Thiel's company had taken an active interest in parabiosis research.
"Parabiosis" means the biological joining of two individuals, and in this context, it entails infusing oneself with young blood. If you're imagining the system the bad guys in Mad Max: Fury Road used to keep themselves healthy, in which they stole the hero's precious blood, you're imagining something surprisingly close to the biology involved in anti-aging parabiosis.
But Thiel might never get to indulge his hematolagnia, because parabiosis treatments in humans really haven't shown much promise. Not yet anyway.
In the Inc. interview, Thiel referred to positive results being seen in lab mice—most likely an experiment by Stanford researcher Tony Wyss-Coray, who was already a well-known figure in Alzheimer's disease research at the time of his June 2015 TED Talk, titled "How Young Blood Might Help Reverse Aging. Yes, Really."
At TED, Wyss-Coray began by musing about how no one had yet found a fountain of youth. Later, he played video of an aging, mentally sluggish lab mouse that had been literally sewn onto a strapping, younger mouse in order to let an unadulterated youth leak into the elder's bloodstream. After the therapy, the old mouse enjoyed some improvements in its mental agility—comparable to having an easier time finding your car in a mall parking lot, according to Wyss-Coray, who serves on the board of directors of the Silicon Valley anti-aging research company Alkahest.
Joe McCracken, a colleague of Wyss-Coray at Alkahest, told me in an interview that the animal results made for "a nice story that went beyond just behavior." McCracken is a veterinary scientist and acts as Alkahest's vice president of business development. Results showed "compelling structural physiological data" in lab animals, according to McCracken, and the mice "seemed to like one another other and get along." But forgive me if I take that second claim with a very large grain of salt.
In another study from Alkahest, researchers introduced young plasma into the bloodstreams of mice, rather than stitching them together. That time, they found "similar changes in terms of enhanced learning and memory," according to McCracken.
As for why blood would work, McCracken and the team at Alkahest still don't know, but they have some ideas. They've broken plasma into more than "100 proteins that are deferentially expressed in aging." Some appear to increase with age, and others decrease. By figuring out what all those proteins are, McCracken said, "We are trying to both understand healthy aging, as well as age-related conditions."
But he added that promising results in animals don't mean anyone should get his or her hopes up about young veins being the fountain of youth. Many results from those animal experiments, he said were "not translated well into humans," and when I asked McCracken if he considered young blood to be a promising anti-aging therapy, he didn't exactly exude optimism. "The short answer is, I have no idea," he said. But, he added, "We are trying to approach this in a very systematic and ethical way, to answer that question."
According to Inc., sometime this summer, Jason Camm, health director at Peter Thiel's investment company, Thiel Capital, reached out to Ambrosia, another Silicon Valley medical research company that competes with Alkahest, and expressed interest in its research. Ambrosia had just begun a human clinical trial looking into the effects of young plasma on June 11 of this year and is still actively looking for young blood donors.
Ambrosia's trial will test for changes in age-related biomarkers, including signs of physical health as well as dementia. The company charges an $8,000 fee to participate and has 600 enrollees, for a total of $4,800,000 in revenue meant to cover blood, lab work, insurance, an ethics review, and administrative costs, according to Science Magazine.
Alkahest, meanwhile, has enrolled Alzheimer's patients in a young-blood study that costs the patients nothing. "The primary objective of this first study is really just to demonstrate safety," McCracken said, rather than testing to see if young blood makes old people leap out of bed and dance like Grandpa Joe in Willy Wonka and the Chocolate Factory. But he told me Alkahest will also be "looking for any biomarkers or any hints of efficacy."
Speaking to Science Magazine, Wyss-Coray claimed that Ambrosia's pay-to-participate model is "basically abusing people's trust and the public excitement around this." He suggests that participants are signing up to pay for something that has a chance of keeping them young, and that at this phase, "there's just no clinical evidence."
But while a rivalry seems to be forming between Alkahest and Ambrosia, the idea of reversing the aging process with young blood was apparently so catchy that researchers outside of Silicon Valley—and indeed the US—decided to get on board. Bundang CHA Hospital, in South Korea, is currently performing a study that looks at the effects of stem cell-rich umbilical cord blood and plasma on people 55 and over.
Notably, however, that study appears to be focused entirely on immune health and physical strength, and it excludes subjects from participating if they have any cognitive impairment. And according to its page on the US National Institutes of Health website, the purpose of the Bundang cord blood study, as with the Alkahest study, is "to carry out a safety evaluation."
But when you're experimenting with a treatment that sounds like the Brothers Grimm made it up, excitement and confusion from the public are a part of doing business, McCracken said. "We have been approached [via email] by people who I would describe as the crazies. We tend not to respond to those," he told me, without explaining further. He added, "I've been to conferences where people joke and say, 'Oh, you're the vampire company!'"
But McCracken enjoys some of the oddball emails he receives.
From time to time, he said, people contact Alkehest, asking if researchers would like case-study information about their loved ones suffering from Alzheimer's, who, they believe, received a jolt of vitality after a blood transfusion. "I think most clinical scientists would say that is anecdotal information," McCracken told me. "But it does give us encouragement."
Follow Mike Pearl on Twitter.