Science- Longevity researchers are working on a new class of anti-aging drugs called "senolytics."
- The drugs target and clear out "zombie" cells that build up as people age.
The same chemicals that give bright red strawberries their vibrant taste and color might also be a secret ingredient to healthy aging. It turns out that a single, special compound found in strawberries, called fisetin, is a zombie cell killer.
Paul Robbins, co-director of the Institute of the Biology of Aging and Metabolism at the University of Minnesota, has been studying fisetin for years, and he's been impressed at how it can help lab mice stay healthy. He has already shown in published research that fisetin, which is also found in other red and rust-colored fruits like apples and persimmons, can extend and improve the lives of lab mice.
But during the pandemic he started to wonder: What if fisetin could help him age better, and improve his immunity, by reducing inflammation, and lowering the levels of potent "zombie" cells building up in his body over time? He started taking a dose of fisetin once every two weeks, hoping it might help boost his immunity — and he hasn't stopped since.
"I have a knee that's kind of cranky — it always seems to feel better right after I take it. Is that real? Who knows," Robbins told Insider.
He says it's entirely possible that everything he's feeling could just be a powerful placebo effect.
"Again, there's no evidence in humans that this sort of treatment has any benefit," Robbins said.
Strawberry chemicals can kill "zombie cells" that build up as we age
Scientists call fisetin a "senolytic" because it targets and wipes out senescent cells in the body, which build up as people age and contribute to age-related health issues. These cells are also called "zombie cells" because they have stopped multiplying, but don't die off. Yet they can still release molecules that trigger inflammation.
The National Institutes of Health is so concerned about senescent cells' impact on aging they're funding $125 million in grants to study them over the next few years. In aging mice, when these zombie cells are wiped out, functionality of key organs like the heart, liver, lungs, and the brain all improve, as systemic inflammation goes down.
"If you're a healthy human when you're 20, 30, or 40, you really don't have a lot of senescent cells, it appears," Robbins said. In fact, senescent cells are critical for embryonic development, telling our fingers when to stop growing, and they can fight off cancerous tumors, too.
"It's when you get older that you find it really associated with conditions like frailty or disease," Robbins said.
In the lab, he is working to develop fisetin-based drugs that may work to clear these zombie cells from the body.
"These trials are ongoing, and I think we will know within the next year or two if there's any real benefit, or if we need better senolytics, or if we need a senolytic plus another compound," he said.
Wait for more research before taking fisetin, experts say
Other longevity experts like assistant professor Markus Riessland, who studies senolytics and the aging brain at Stony Brook University, says people at home should practice just a few years of patience as scientists like Robbins endeavor to figure out when, how, and at what dosage fisetin might work to improve aging.
There are already plenty of supplement-peddlers on the internet, selling products that are not regulated for safety or quality. In addition to being for sale in an unregulated space, high doses of fisetin could be toxic. The proper dosage and potential harms for patients with other health issues haven't been uncovered either. So while Riessland is excited about the promise of senolytic drugs like fisetin, he's not ready to start pill popping just yet.
"I don't want to say 'take it,' I don't want to say 'don't take it,'" Riessland said. It's still unclear how well fisetin will work, and how safe it is. "I would wait a little bit, to be honest."
In the meantime, you can find plenty of natural fisetin — as well as other anti-inflammatory compounds that may help fight aging — abundant in strawberries as well as onions, apples, and a whole bunch of other colorful fruits and vegetables.
And there is a small, but growing, body of research suggesting that people who eat more strawberries may reduce their Alzheimer's risk, curb cognitive decline and even improve blood sugar and heart health. So go ahead, bite into that bright red strawberry already.