These compounds are said to fight aging by clearing “zombie cells” out of your body. Is there any science to back this up?
These compounds are said to fight aging by clearing “zombie cells” out of your body. Is there any science to back this up?
References
JCI - Strategies targeting cellular senescence
Targeting senescent cells: approaches, opportunities, challenges - PMC
Hello and welcome to the Nutrition Diva podcast, a show where we take a closer look at the latest nutrition headlines, research, products and trends, and sort fact from fiction. I’m your host, Monica Reinagel, and today we are exploring some fascinating new research on compounds that might actually help reverse aging at the cellular level.
Now, we’ve definitely heard this kind of thing before, right? This type of claim is stock-in-trade for the multi-billion dollar supplement industry, which sells an awful lot of supplements with very flimsy evidence to support them. And, indeed, the category of compounds we’re talking about today–senolytics—is already being marketed as the latest anti-aging miracle.
My goal today is not necessarily to give senolytics a thumbs up or thumbs down–because I think it’s far too soon to say. Instead, I want to brief you on what we do and don’t yet know about them, so that if you run across these products, or these claims, you’ve got a little background with which to assess them.
Let's start with this intriguing idea of "zombie cells." More scientifically known as senescent cells, these are cells that have been damaged or stressed to the point where they stop dividing and functioning. But they don't die off, like healthy cells typically do. Instead, they hang around in the body, not doing anything useful. Even worse, they secrete inflammatory substances that can harm neighboring cells and tissues.
We’ve all got some of these senescent zombie cells floating around. But, as we age, they gradually accumulate in our bodies. One theory of aging is that this buildup of senescent cells contributes to chronic inflammation, tissue damage, and is a major driver of the aging process. They may play a role in diseases like arthritis, osteoporosis, heart disease, diabetes, and even dementia.
Senolytics is a class of compounds (either naturally occurring or engineered) that target these “undead” senescent cells by inducing cell death, which then allows them to be cleared from the body. The idea is that by removing these problematic cells, we might reduce inflammation, improve tissue function, and potentially slow down certain aspects of aging. It’s exciting to think that instead of just treating symptoms of aging, in a decades-long game of medical Whack-a-mole, we could potentially target one of the underlying mechanisms of aging itself.
Yet, as intriguing as the concept is, we're still very much in the early stages of understanding how effective, safe, and practical these senolytic compounds might be for widespread human use.
Quercetin is one of the naturally occurring compounds that have been identified as a senolytic. This flavonoid is found in a wide variety of foods, including capers, onions, kale, berries, and tea and it has a long history of use as an antioxidant, anti-inflammatory, and immune-modulating agent.
More recently, researchers noticed its ability to selectively target senescent cells—inducing cell death without harming healthy cells. That, plus its well established record of safety, has put quercetin at the forefront of senolytic research. While most of the research on senolytic compounds so far has been limited to studies looking at cells in petri dishes or animal studies, a combination of quercetin and a drug called dasatinib has made into early phase, human clinical trials–where they have seen promising results. (Dasatinib has been around for about 20 years. It is approved for the treatment of certain types of leukemia.)
A recent study at the Mayo Clinic tested the effects of a 20-week regimen of quercetin + dasatinib in post-menopausal women and measured beneficial effects on bone formation, for example. However, the benefits were mostly seen in women who had higher levels of senescent cells going into the study–which kind of makes sense. But it suggests that this particular type of anti-aging therapy may not be effective for everyone. Those who, for whatever reason, have a higher burden of senescent cells may get more benefit. This study also wasn’t long enough or large enough to sort out questions about ideal dosage or timing or the long-term effects.
Other, even more preliminary, trials have suggested possible benefits in terms of cognitive function and in specific pulmonary conditions. And there are lots of other senolytic compounds, both natural and engineered, in the pipeline at even earlier phases of research and development. The hope is that we might eventually be able to design highly specific senolytic agents to target specific organs or cell types or disease processes. But it is early days for all of this.
As you may be aware, scientific research, and medical research in particular, has recently hit a major roadblock, in the form of drastic cuts to research funding and to the agencies that oversee and coordinate the most promising medical research. So, unfortunately, progress on this promising area of anti-aging research may slow to a crawl for the foreseeable future. Which is a shame, because it’s hard enough to be patient while promising therapies make their way through the long process of research that is required to bring them safely to market. Even harder when researchers are forced to abandon promising research mid-stream.
Meanwhile, senolytic supplements have already entered the market. As you’re probably aware, nutritional supplements are regulated far less rigorously than pharmaceuticals. While companies cannot make specific claims about curing or treating diseases, aging is not considered a disease. So, nutritional supplements can be positioned as “anti-aging” products, and with some clever inferences, marketers can gesture toward and capitalize on the scientific developments in senolytic research.
The bottom line? While senolytics represent a genuinely exciting area of research–and one I'll be following closely–I encourage you to approach senolytic supplements with a healthy skepticism.
If you're intrigued by the potential benefits of these natural compounds, a practical step you can take now is incorporating more quercetin-rich foods—such as apples, kale, and berries—into your meals.Lifestyle habits can also play a role here. Regular physical activity promotes the clearance of senescent cells–which may be why exercise seems to be one of the most potent angi-aging therapies of all.
There’s also some evidence to suggest that intermittent fasting or time restricted eating may enhance the clearance of senescent cells. So, if that’s a strategy or technique that you are following for other reasons, you may be getting a fringe benefit in the form of fewer so-called zombie cells!
My thanks to the listener whose question prompted today’s episode! Even though this research is still in its infancy, I found it really interesting–and I hope you did, too!
If you have a question you'd like me to answer, you can email me at nutrition@quickanddirtytips.com
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Nutrition Diva is a Quick and Dirty Tips podcast. Steve Riekeberg is our audio engineer, Brannan Goetschius provides script editing. Holly Hutchings is the Digital Operations Specialist and Morgan Christianson heads up Podcast Operations & Advertising and we also get indispensable support from Nat Hoopes. Thanks to all of them and thanks to you for listening!