Your body is full of 'zombie cells' that speed up aging. Mayo Clinic just found new ways to fight them, including one from tomatoes.
As we get older, our bodies collect cells that refuse to die. They stop doing their jobs, but they don't go away, and they keep leaking chemicals that cause inflammation and damage the healthy cells around them. Scientists call them senescent cells. Everyone else calls them zombie cells.
Now a group of seven studies from Mayo Clinic's Kogod Center on Aging shows how to find these cells, why they cause so much trouble, and some new ways to fight them, including a natural compound from tomatoes. In old mice, the treatments cut inflammation and made the animals stronger and sharper (Mayo Clinic via EurekAlert, ScienceDaily).
Most of this is in mice, not people, yet. Here's what they found, in plain words.
What is a zombie cell?
Your body is made of trillions of cells, and most of them divide to make new ones. When a cell gets old or damaged, it's supposed to either repair itself or die and get cleaned up.
A zombie cell does neither. It stops dividing but stays alive. And it isn't quiet: it keeps sending out inflammatory chemicals, like a broken smoke alarm that never stops beeping and annoys every neighbor on the street. A few are fine, and young bodies clear them out. As we age, they pile up, and that steady inflammation is linked to many diseases of getting older (Mayo Clinic via EurekAlert).
What the seven studies found
1. Zombie cells aren't all the same. They look and act differently depending on which part of the body they're in and what turned them into zombies. That's made them hard to find. Mayo researchers built a tool called SenMayo, a kind of fingerprint made from which genes a cell has switched on. It spots zombie cells across different tissues, it was checked on bone samples from older adults, and it's now used by labs around the world (ScienceDaily).
2. Their tiny power plants are part of the problem. Inside every cell are mitochondria, the small "power plants" that make energy. In zombie cells, broken mitochondria leak bits of their own genetic material, which sets off the body's alarm system and keeps inflammation going. Faulty mitochondria also change which inflammation genes stay switched on (Mayo Clinic via EurekAlert).
That's a big deal, because it means doctors might one day turn off the harmful "beeping" without having to kill every zombie cell.
3. A compound from tomatoes calmed them down. Researchers tested a natural compound called tomatidine, which comes from a substance found in tomatoes. In old mice, it reduced zombie-cell signs in the liver, skin and brain, lowered inflammation in the brain, and the mice became less frail, better coordinated and better at memory tests (EMBO Molecular Medicine abstract, via University of Minnesota). Interestingly, it didn't kill the zombie cells. It quieted the inflammation they give off.
4. Drugs that clear zombie cells helped old brains. Other experiments used "senolytic" drugs (senolytic means zombie-cell killer) and genetic tools to remove zombie cells from the brains of old mice, which cut inflammation and improved how the mice did on thinking tasks (Mayo Clinic via EurekAlert).
5. A possible blood test for aging. The team found that a protein called IL-23R in the blood tracks with zombie cells and aging. One day, a simple blood test like this might show how fast someone's body is aging, and whether a treatment is working (ScienceDaily).
"This body of work is moving the aging field forward to precisely identify, understand and target the specific senescent cells that contribute to age-related dysfunction," said Mayo Clinic scientist Marissa Schafer, whose lab led several of the studies (ScienceDaily).
The work is part of SenNet, a national project funded by the National Institutes of Health to map where zombie cells build up in the human body over a lifetime.
Has any of this been tried in people?
A little, and the results are mixed. In a Mayo-led trial published in 2024, 60 older women took a zombie-cell-killing combination (dasatinib and quercetin) for 20 weeks. Overall, it didn't meet its main bone goal. But women who started with the most zombie cells did see better bone results, which hints that these treatments may help some people more than others (Mayo Clinic News Network, PubMed). That's exactly why these new tools to tell zombie cells apart matter.
