Jamie Justice admits she has no poker face. As executive director of XPrize Healthspan, a philanthropic and corporate sponsored competition, Justice oversees one of the most buzz-worthy science competitions today. The contest, launched in 2023, attracted nearly 200 applicants from groups around the world who think they can help people to live not just longer lives, but healthier ones.
When the 15-member judging panel met in early summer to pick the top 10 teams who would continue on in the seven-year competition, Justice excused herself. “I couldn’t be in the room because my face shows everything,” she says, since she became familiar with each of the teams and their various approaches to extending human life.
Read more: TIME’s 2026 Longevity Leaders
Both in the scientific community and the commercial market, there is no shortage of ideas—from legitimate, rigorously developed approaches to more fantastical schemes—for a fountain of youth. XPrize Healthspan exists to bring some order to that chaos, and legitimacy to the process of developing and, most importantly, testing ideas in longevity. Applicants for the prize, which has a total purse of $101 million, allocated in segments throughout the seven-year competition, included teams from academic research institutes as well as biotech and startup groups. All had to follow a few basic rules; they had to show early promise in human studies that their approach could improve health in three critical areas: muscle function, brain function, and immune function. All teams were judged based on standard measurements of these three functions that XPrize committees of experts had specified, to ensure that all projects were evaluated using the same metrics. The judges announced the top 10 projects on Aug. 11.
“This is where I get the most excited, when things get really sort of dirty and ugly,” says Justice, who spent time researching geroscience at Wake Forest University before coming to XPrize. “You’ve got biohackers selling you this, and you have a bro guy over here that wants you to take so much protein that you’re going to die. What we need to do is have a strainer, a filter where everybody is held to the same standard. There may be something really worthwhile and useful out of some of these things that seem harebrained. What XPrize does well is invite everyone in, teach them how to do the science to get to a level of super credibility. It’s an alliance that comes together to set the frameworks for the start line, a finish line, and how to get there.”
The projects are as varied as you might expect approaches to longevity to be—ranging from the latest anti-aging trends in Asia involving extracellular vesicles, to stem cells and more traditional, well-established programs that include exercise and supplements. Two of the teams are from Japan, one from South Korea, one from China and six from the U.S. Two of the groups are studying repurposed drugs for their potential in extending life, while the Korean team is investigating a novel longevity drug. Four projects involve supplements and five rely on biologic compounds including extracellular vesicles, peptides, and antibodies.
Both teams from Japan are working with the vesicles, which carry a wide menu of molecules in the body, from enzymes to peptides, fats and genetic material. But the teams are taking very different approaches to optimizing what these vesicles can do to improve health.
Time Traveler Corp., a biotech startup launched in 2024 by Rieko Akiyama to bring ideas from her father’s research in tumor biology and cancer research at University of Tokyo to longevity is one of the teams focusing on this approach. Tomoatsu Hayashi, a project assistant professor at the University of Tokyo and co-CEO, started by studying human cells to find ways to make the vesicles at scale. Smaller versions of these vesicles, called exosomes, which are made when cell membranes fold inward, and pinch off tiny bubbles, are an increasingly popular component of anti-aging beauty products in Japan and Asia, but they remain untested from a longevity perspective, and Hayashi and his team were eager to study them in a more rigorous fashion.
Akiyama gave the team what turned out to be its XPrize-leading idea. She noted that during the COVID pandemic, there were more discussions about turning away from animal-derived materials in science, which are heavily regulated to ensure safety before they develop into products used in people, to plant-based sources, including for food products like mayonnaise. “I wondered whether human-derived exosomes could also be replaced by plant-derived exosomes, which might offer advantages in terms of safety, scalability, and ethical considerations,” she says through a digital translator during a recent interview near Hayashi’s labs at the University of Tokyo. “I brought this idea to my father and asked whether plant-derived extracellular vesicles could become a new approach for promoting healthy longevity. That conversation became the starting point of our plant-derived exosome business.”
Hayashi and his team started with edible plants and algae, assuming that those would have the strongest safety profile for eventual human use, and screened more than 140 species, including 95% of those that grow in Japan. While human exosomes were widely studied, those from plants were still a mystery, and “we didn’t know if plant exosomes would have the same effect in human cells,” he says. But starting first with mice and then with human cells, they showed that in fact, plant exosomes worked in very similar ways to human-derived exosomes, proving Rieko’s initial hunch correct. And of the species, it turned out exosomes from parsley showed the strongest effects.
In mice, the parsley-derived exosomes lowered inflammatory factors that are responsible for many aging processes in cells. Animals who were fed the exosomes in their water were able to maintain muscle strength, as measured by the longer time that these mice could hang from a wire cage compared to similarly-aged mice that didn’t get the supplement.
The team saw similar benefits in lowering inflammation in a small group of 40 people who started taking the supplement pill once a day. Anecdotally, the people reported sleeping more consistently and deeply and feeling more energy during the day. The animal and human data were enough to give the team a chance at testing their product further in more people in the next phase of the XPrize competition. That trial will evaluate volunteers on muscle function, walking, leg presses, cognitive tests, and tests looking at inflammatory markers in their blood.
The other Japanese team, also from University of Tokyo, is likewise banking on exosomes. But to address supply issues, instead of plants, they turned to stem cells. Keisuke Goda, professor of chemistry at University of Tokyo, decided to tackle the problem of getting exosomes to the cells where they are needed most. Relying on his chemistry and engineering background, he designed so-called super exosomes with specific molecules on their surface that can draw them to aging cells like a magnet. Because they are revved up to target aging cells, they can deliver the lipids, genetic material, and other compounds cells need to keep them acting like younger versions of themselves. “We knew from previous studies that exosomes secrete a range of molecules including growth factors, metabolic enzymes, lipids, and DNA and RNA, and previous reports showed that injecting young exosomes into aged mice rejuvenated the aged mice,” says Goda. “But there is a delivery problem.”
As part of the XPrize, Goda and his team will start testing the super exosomes in more than 100 people in a formal trial see how they affect muscle, brain, and immune cells.
He is confident that they will see similarly encouraging results as they saw in their mouse and human cells studies, which showed that older human cells in the lab treated with the exosomes had reduced markers of aging and appeared rejuvenated. “We know they work,” says Goda. “It’s exciting. When we saw the results, we doubted it was true. But the cells were rejuvenated, they were not dying.” About 25 months after they started studying the super exosomes in mice, the untreated animals are starting to die, he says, but the treated ones are not. “We of course want to see the actual effect in humans, assuming it’s safe,” he says.
Not all of the top 10 teams involve innovative or cutting edge scientific approaches. The group from Mount Sinai earned its spot by combining three, more familiar strategies: exercise and two supplements, one that’s been bandied about the aging community for a few decades now—rapamycin—and another, spermidine, that came out of work from one of the Mount Sinai scientists as a factor to control inflammation associated with aging. During the COVID pandemic, Dr. Miriam Merad, director of the precision immunology institute at the Icahn School of Medicine at Mount Sinai, and her team noticed a strong connection between age and inflammation that made older people more susceptible to the effects of a COVID infection. That led to a hypotheses about the role that inflammation might play in a range of age-related diseases, including heart disease, respiratory conditions, and muscle loss. “What we realized was that the inflammatory response was contributing to age associated diseases,” she says. “It’s very established what happens with age when organs decline—they acquire somatic mutations from the exposures we have, and at the same time as all of our organs age, our immune system is also declining, and producing more inflammatory molecules. Age-associated diseases are aggravated, or precipitated by chronic inflammation.”
Addressing inflammation, then, might be a powerful way to control the aging process, and in further studies in mice and with human cells in the lab, Merad and her team zeroed-in on a compound that older cells weren’t making as robustly as younger ones—a polyamine called spermidine. By giving older mice the supplement spermidine, they saw improvements in the animals’ immune responses that tipped the balance away from the chronic state of inflammation associated with accelerated aging. “Once we saw the data in the lab, we all started taking it ourselves because [the data] looked so good,” says Dr. Thomas Marron, professor of immunology and immunotherapy at the Icahn School of Medicine at Mount Sinai and the principal investigator of the team’s study of the compound.
The researchers also included rapamycin, a drug approved by the U.S. Food and Drug Administration to treat rejection in kidney transplants, as well as certain types of cancer, in the study as well. Because some, but not all, studies showed rapamycin extended the life of animals, it’s been a controversial product in the longevity field, with some in the health community using the drug off-label in the hopes of a longer and healthier life, despite the lack of solid evidence in human studies that it can have this effect.
That’s one of the reasons the Mount Sinai team is eager to put it to the test, in combination with an exercise regimen and spermidine. Their rationale in combining the two supplements and physical activity lies in the fact that aging isn’t likely directed by a single compound or process, but the net result of a multitude of body processes, so slowing aging will likewise require a multi-pronged strategy. Marron also expects that given the biological differences among people, some may respond more to one supplement, while others respond to the other, and still others may respond best to the exercise regimen. Studying them together could provide the first hints about which components are contributing to slowing aging, and by how much. The researchers will be taking blood samples throughout the coming year, and looking at certain markers of inflammation and as well as conducting tests of hand grip and leg strength, respiratory function and evaluations of changes in fat composition with MRI images. The participants will also take standard cognitive tests to monitor changes in their processing speed and executive function skills such as planning, memory, attention, and impulse control.
“The goal of XPrize is to improve health span by 10 years, and ultimately by 20 years,” says Marron. “But that’s hard because there is no validated way to measure health span, or aging. So the real goal is to inject more science into this process.”
The top 10 teams earned $1 million each to test their ideas in a larger group of people over the next year, and hopefully show improvements in the three areas targeted by the XPrize: muscle, brain, and immune function. “I love to have a front seat and watch the next phase of this go from hype cycle to durable evidence if there is any,” says Justice. But she also acknowledges that aging is a varied process, and no single, uniform solution that applies to the widely diverse human species will likely emerge. “We age at different rates, we have different constellations of diseases and functional decline, so a one-size-fits-all is probably unlikely,” she says. “I expect a lot of failure, but the question is whether you can take that failure and make something useful out of it. Does it become compost to build something better? There needs to be a lot more work from the field within geroscience to really lean on learnings. This is what gets me excited.”
