Bad News, Oligarchs. The Dark Fantasy of Harvesting Young Organs for Longevity Just Collapsed.

3 min readHere’s what you’ll learn when you read this story:Whether fanciful sci-fi or real-world conspiracy theories, the idea that the transplantation of young organs will, in effect, de-age the recipient is a popular one. However, a new study finds that the opposite is actually true, meaning a young heart will rapidly age when placed in an older body and vice versa. Scientists discovered this phenomenon by grafting extra hearts onto mice and then performing DNA-methylation tests to see how much the organs aged—or de-aged—over the course of several months.From novels like Never Let Me Go to dystopian sci-fi films like The Island, the transplantation of organs from the young to the old—and from the poor to the rich—is a well-worn dystopian trope. But in recent years, that trope has taken a “stranger than fiction” twist. Whether as a demented conspiracy theory of Hollywood blood-harvesting, or as a real-life example of authoritarian leaders nonchalantly considering transplantation as the key to immortality, the pseudoscientific idea that young organs somehow rejuvenate old bodies has wormed its way into real-world politics.But fortunately for us, that’s all it is: pseudoscience.A new study on the pre-print server bioRxiv, led by researchers at Harvard Medical School, determined that transplanted organs eventually assimilate to the recipient’s age. So if an older person receives a young organ—a typical scenario for most transplants—that organ will gradually match the age of the recipient in due time. In other words, organ harvesting is decidedly not the key to immortality. The reverse also held, as older organs tend to take on youthful characteristics when placed in a younger body. This discovery could help relieve the organ shortage crisis by expanding the donor pool to include older hearts.This all leads to a curious question: Why are these organs shifting to roughly the age of the body in which they’re transplanted? To find the answer, Harvard University’s Jesse Poganik and his team grafted extra hearts onto three ages of mice: young (three months old), middle-aged (12 months) and old (18 to 20 months). Six months later, the scientists measured levels of DNA methylation (DNAm) to detect cellular damage, a key byproduct of aging. Using three kinds of molecular clocks that track this process, they found that young hearts grafted onto old mice experienced accelerated aging, while old hearts on young mice grew biologically younger.To test whether the same phenomenon occurs in humans, the team searched historical heart transplants at Boston’s Brigham and Women’s Hospital for cases with biopsy samples they could run DNAm tests on. According to Nature, they found 11 with substantial donor-recipient age gaps—8 to 24 years for old hearts given to young patients, and 38 to 50 years for young hearts given to old ones. In every case, the heart had taken on the biological age of its new host.“The remarkable thing is that we found exactly the same effects that we saw in the mice,” Poganik told Nature. “Some, but not all, functional measures tracked the prediction that these older hearts in younger individuals functioned as if they were biologically younger, and vice versa.”The mechanism driving this shift remains unclear, however. João Pedro de Magalhães, who studies aging at the University of Birmingham (and who spoke at length with Popular Mechanics about aging back in 2024), tells MIT Technology Review that the recipient’s immune system might be responsible, since it could affect known biomarkers of aging in the organ itself. Poganik and his team offer another explanation: that accumulated damage is traded between the recipient’s body and the transplanted heart.“Exchange of accumulated damage between the recipient and the graft following transplantation would simultaneously explain why old hearts are rapidly rejuvenated when placed into a young environment, which can effectively dilute damage,” the authors write, “and why young hearts placed into an old environment, and thus exposed to higher levels of damage, rapidly age.”Understanding this aging mechanism could allow physicians to reconsider older organs for transplantation, knowing that they’ll effectively de-age within a younger body. However, the authors admit that more studies need to be done to understand just how long those rejuvenating effects last.Darren lives in Portland, has a cat, and writes/edits about sci-fi and how our world works. You can find his previous stuff at Gizmodo and Paste if you look hard enough.