Researchers at Stanford University have developed a tool that can compute the “biological age” of human organs by processing a vial of blood.

The tool, unveiled in Nature Medicine on Wednesday, was developed by a research team spearheaded by Tony Wyss-Coray, a Stanford Medicine professor who has spent almost 15 years studying aging and says the tool could “change our approach to health care.”

“It could help us shift from sick care to health care, and empower people to take care of their own body,” he said.

Scouring a draw of blood for thousands of proteins, the tool works by first comparing the levels of these proteins with their average levels at a given age. An artificial intelligence algorithm then uses these gaps to derive a “biological age” for each organ.

To test the accuracy of these “biological ages,” the researchers analyzed data from about 45,000 people from the UK Biobank, a database that has collected detailed health information from over half a million British citizens for the past 17 years.

When they analyzed the data, the researchers found a clear trend for all 11 organs they studied; biologically older organs were significantly more likely to develop aging-related diseases than younger ones.

The brain’s biological age, Wyss-Coray said, was “particularly important in determining or predicting how long you’re going to live.”“If you have a very old brain, those people are going to die the soonest out of all the organs we looked at,” he said.

Those with “extremely aged brains” — the 7% whose brains scored the highest on biological age — were over 12 times more likely to develop Alzheimer’s disease over the next decade than those with “extremely youthful brains” — the 7% whose brains inhabited the other end of the spectrum.

Wyss-Coray’s team also found several factors — smoking, alcohol, poverty, insomnia and processed meat consumption — were directly correlated with biologically aged organs. Poultry consumption, vigorous exercise, and oily fish consumption were among the factors correlated with biologically youthful organs.

With these results, Wyss-Coray’s team set about testing the tool on people in real time. The fifth person they tested was Paul Coletta, an entrepreneur who decided to participate in the test after reading a preliminary Nature paper that had been sent by a friend. The test found that Coletta, then 60, had kidneys that were biologically 68 years old.

“All the typical kidney biomarkers came back as normal, but I followed up with an ultrasound, and it revealed a large renal cyst in my left kidney,” he said. “It found an early signal of decline, and it empowered me to act.”

Coletta was so impressed that he agreed to found Vero Bioscience, a company that now has an exclusive license from Stanford Medicine to commercialize the product, with Wyss-Coray.

Coletta said he planned to make the tool the core of an “at-home AI health clinic.”

“It’s not just a kit where you send us your blood and you get a result,” he said. “We want to support the consumer through the journey of what the intervention should be for that organ.”

The test, Coletta said, would cost $200 once it could be operated at scale.

Malia Fullerton, a professor of bioethics and humanities at the University of Washington, said that while the tool “seems very promising as a global technique,” there were several ethical concerns when it came to its application.

“I could imagine for folks who are interested in being super agers, a desire to get rid of their quickly aging organs and replace them with new ones,” she said. “I see the first negative consequence — particularly if this goes directly to consumer — being putting strains on our organ donation system, which is already under complete duress.”

Wyss-Coray said the risks of an organ transplant currently far outweigh the potential reward of replacing an aged organ with a healthy one, particularly since the test was merely a risk assessment. In any case, he said, it would be challenging to solve the issue completely.

“You can’t prevent people with money from going to a place where they can get the surgery they want,” he said. “But I think it’s a remote possibility.”

Fullerton said there is also a question about how insurers would use the information. While there is imperfect non-discrimination legislation for health and employment insurance, she said, no such legislation exists for life insurance.

“Underwriters trying to say things about one’s likelihood of living a long life or living disease-free surely would make use of such information if it were validated and shown to be broadly predictive,” she said.

Wyss-Coray said it would be important to make sure “that information is private and withheld from your employer or from health insurance.”

The current insurance model, he said, might also change if the test became broadly accepted.

“It is an incentive for insurance to actually know and help you pay for it before you have a heart attack, and then you have an operation that is much, much more expensive than doing preventive care before,” he said.

Fullerton also raised concerns about the use of the UK Biobank, the database Wyss-Coray’s team used. The database, she said, is “notoriously monochromatic,” as subjects skew heavily white.

“I don’t have any reason to believe that organs would age differently in different groups, but it is extremely important that we do our work for biomedical research in diverse cohorts, so that we can ensure the information we are generating is generalizable to all populations of patients,” she said.

Wyss-Coray said he hoped to remedy this issue by conducting studies on Asian and Arab populations in the future. However, he said he is confident in the global applicability of his results.

“I think overall, we find that basic principles of biology are common to mankind,” he said.

Wyss-Coray and Coletta hope to commercialize the test with Vero Bioscience within the next three years. And as for the future of the technology, Coletta has high hopes.

“I see it as being the gold standard of health biomarkers, used everywhere by every physician and every consumer, so that you’re constantly staying one step ahead of disease,” he said. “Consumers being empowered to take their health into their own hands.”