Did you know that your body has “zombie” cells? Although senescent cells aren’t completely dead, they don’t function like living cells and can wreak havoc on tissues, hence the nickname. Scientists believe that these cells may be responsible for the damage that occurs to the lungs, bones, and even the brain as we age. This raises the question: could getting rid of these zombie cells help us stay healthier for longer?
A treatment aimed at killing zombie cells could help older women build new bone and prevent bone loss, a common problem of aging after menopause, according to a new study published in the journal Nature Medicine.
Here’s what you need to know about the latest research breakthroughs in the fight against aging.
What are “zombie cells”?
Scientists formally call these “senescent cells,” which are cells that are dying but not completely dead. They build up as we age, causing inflammation and damaging healthy cells.
The team of Mayo Clinic researchers who wrote the latest paper said they were “leaders in the field.” [who] “We demonstrate that senescent cells are not simply a consequence of aging but may actually promote aging,” Paul Robbins, director of the Institute of Aging and Metabolic Biology at the University of Minnesota, tells Yahoo Life.
Zombie cells are thought to accumulate in all tissues, but they don’t necessarily behave the same in one part of the body as in another. But studies, mostly done in mice, suggest that wiping them out could help extend healthy lifespan by slowing the damage that leads to age-related health problems, including loss of bone density, lung scarring and Alzheimer’s disease, Robbins says.
What did the new study find?
Based on previous work in mice and petri dishes, the scientists hypothesized that senescent cells contribute to osteoporosis, a type of age-related bone loss that affects about 13 percent of Americans over 50 and about 20 percent of women, according to the most recent national estimates from the Centers for Disease Control and Prevention.
A team at Mayo Clinic tested a combination of the commonly used cancer drug dasatinib and quercetin, a compound found in some foods and sold as a supplement that may help kill senescent cells, in half of 60 healthy postmenopausal women (the other half served as a control group and received no treatment). Biomarker tests suggested that the treatment, known as D+Q, led to 16% more new bone growth than the control group. But there was a caveat.
The effects were only apparent after two and four weeks, and by the end of the study the two groups were balanced. And the drug that killed zombie cells didn’t slow bone loss, it just increased the rate at which bone was built up.
Perhaps most importantly, the treatment worked best in women with a high volume of senescent cells. The study found that “only about 30 percent of women over 60 may have enough senescent cell volume to respond to this particular drug combination,” study co-author Sandeep Khosla, PhD, an osteoporosis researcher at Mayo Clinic, tells Yahoo Life. He adds that volume, or zombie cell density, tends to increase significantly after age 70, so starting treatment at that age may be most effective.
What does that mean for anti-aging and longevity?
This is a good first step, say Khosla and Robbins. The study was a clinical trial testing a treatment in humans that could kill zombie cells. And the fact that it worked is promising, says Robbins.
The science of how and why humans age is still young (for goodness’ sake), and attempts to slow or stop it are even newer. Scientists have found plenty of biomarkers, or signals, of biological age — changes in DNA — but the challenge is figuring out which ones might be “druggable targets,” Robbins says. That’s why he and Khosla focused on zombie cells.
Based on animal studies, they are among the scientists who believe that “reducing the number of senescent cells will lead to increased healthspan,” he said, but added that “there are other targets as well.”
D+Q is one of several “anti-aging drugs” that may protect against the harmful process of aging, but there’s still a lot we don’t know about how to best use it. For example, the new study found that this particular treatment doesn’t work very well unless people already have a lot of zombie cells, which Khosla says aren’t easy to measure, at least not to slow bone loss. But figuring that out can help scientists know when the treatment is effective, and finding the right timing and dosage can help make it more effective. And D+Q isn’t the only drug with the potential to fight cellular senescence.
If quercetin helps prevent aging, should you take it?
You might be tempted to take quercetin because it has been studied for its anti-aging properties and is available in health food and supplement stores. However, many experts recommend against it, because quercetin is a flavonoid, an antioxidant compound that gives color to fruits and vegetables such as citrus fruits, blueberries, apples, onions, and parsley, according to the Mount Sinai Research Institute. Robbins cautions, “We don’t know if the amount people take every day is enough to kill senescent cells.” But the study suggests that combining quercetin or another flavonoid, fisetin, with other drugs may be enough. But Robbins and her partner started taking fisetin once every two weeks after they published a paper that said quercetin could reduce the risk of severe COVID.
The biggest risk with these supplements is that they’re unregulated, so you don’t know what’s in them, and companies often make exaggerated or false health claims. [a vitamin shop]”We don’t know if it’s pure or not,” Robbins said.
But even if you buy the purest form of quercetin, it’s not “a very effective anti-aging agent” — a zombie-cell killer — “on its own,” Robbins says. Even if it was, he says, the new research highlights a very important point: “Taking a drug to slow aging at age 20 is not going to do you any good, and it may even do you harm.”
