Every cell in your body has a predetermined life span. Some cells live for a few days, while others live for decades. At the end of that life span, each cell undergoes a process called apoptosis: The cell breaks apart and the immune system carries the pieces away. But as we age, this system can go awry.
Enter senescent cells. These dysfunctional cells earned the nickname of zombie cells because they are neither alive and multiplying nor are they broken down and carted off by apoptosis. Instead, they build up and interfere with how healthy cells communicate with each other, impair the body’s ability to get rid of old mitochondria (the powerhouse of the cell), reduce the function of stem cells, and damage the healthy cells around them. Ultimately, they cause everything from frailty and cognitive impairment to inflammation and chronic diseases. They can even worsen viral infections like COVID-19, my colleagues and I reported in the journal Science last June.
There is research being done every day to investigate what permanently kills off these cells, and after conducting several trials and studies, we may have an answer.
Senolytics and fisetin
Drugs and nutraceuticals called senolytics are designed to rid the body of senescent cells by inducing apoptosis. They include dasatinib (a cancer drug), quercetin, and fisetin. The latter two are plant flavonols. Fisetin, the more powerful of the two, can be found in many fruits and vegetables:
strawberries: 160 microgram/gram (μg/g)
apples: 26 μg/g
persimmons: 10.6 μg/g
onions: 4.8 μg/g
grapes: 3.9 μg/g
kiwi fruit: 2.0 μg/g
A healthy diet that contains fruits and vegetables that are high in fisetin is extremely beneficial and will result in positive long-term effects for your body. But it is difficult to get the amount needed to get rid of senescent cells through food alone, so a senolytic or nutraceutical supplement might be beneficial.
Supplements are available in 100- to 500-mg strengths, but there are no human studies on the most effective dosage. Animal trials suggest that range is safe, but more xhuman trials are needed. It’s important that you consult with your doctor before beginning any supplement.
Matthew Yosefzadeh, PhD, a postdoctoral fellow at the University of Minnesota. Dr. Yousefzadeh has published more than 30 scientific publications with an emphasis on cellular senescence and aging. He has led numerous projects researching the efficacy of fisetin. Disclosure: He serves as an unpaid advisor on the scientific advisory board for SRW Laboratories, which produces a supplement with fisetin.