I’ve been involved in what’s called functional medicine for most of my career. Our guiding philosophy was that we weren’t satisfied treating disease symptoms exclusively with pharmaceutical drugs. We wanted, to the degree that we could, to address the root causes of disease. Well, what advances in the biology of aging have made clear over the past decade or so it that aging itself is the root cause of disease. I’m talking about the most common ones – heart disease, dementia, diabetes, osteoarthritis – which develop in mid-life and beyond and shorten and sometimes ruin our lives. We’re now at the point we’re we can identify the distinct, but interrelated, bio-chemical processes which together drive aging – the so-called “hallmarks of aging.” And that is huge. 

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Aging is no longer regarded as this fundamentally mysterious thing that will always be beyond our control. We’re beginning to come up with therapies that can slow these processes down. Nowhere is the buzz these days more intense than around ‘senolytics’. The term refers to a handful of supplements which contain, in concentrated form, compounds found in many fruits and vegetables. They offer the potential to turn the dial down on chronic inflammation, one of the prime movers, if not the main one, behind the aging process. Most people, even health-conscious folks, have probably never heard of senolytics. I’m betting that will change over the next few years. Here’s what you need to know now: 

What’s in a name? 

We get the term senolytics by combining “senescent,” which means old and tired, and “lysis” which refers to destruction. Senolytic compounds destroy tired, old cells. That’s sounds pretty straightforward so you might ask why does the body need help doing that? Doesn’t it take care of its own housekeeping? 

The zombie cell story.

Our bodies do destroy old cells, especially with the cells that turn over frequently, like in the skin or the gut, when they begin to wear out or are in danger of turning cancerous due to DNA damage. That’s called apoptosis. But some cells evade the death sentence and become senescent. They stop dividing and just get old, becoming progressively worse at doing their assigned jobs. And as we get older, our immune systems become less able to clear out these cells on their own. Consequently, they just hang around, hence the term “zombie cells.” And just like zombies in the movies, they aim to do us harm. They begin to secrete inflammatory molecules, a major contributor to the chronic inflammation that promotes just about all of our dreaded diseases of aging. 

Senolytics to the rescue? 

A little over a decade ago, researchers at the Mayo Clinic began publishing a series of landmark papers which found that compounds like fisetin (found in strawberries, apples, onions and cucumbers) and quercetin (in apples, capers, onions, kale and berries), both members of the antioxidant flavonoid family, helped dismantle the senescent cells’ protective defenses. Dosed up, the mice immune systems were able to clear out the zombies more effectively. Consequently, the researchers saw improvements in muscle function, insulin sensitivity, and bone density – what we’d love to have for our seniors – and in the case of fisetin, mouse life expectancy was increased by 10-15%.

The human story.

The mouse research is compelling but there’s always the $64,000 question: Will it work, or how well will it work, in humans? We don’t have a satisfying answer yet. The evidence from clinical trials is so far modest but researchers from the Buck institute and the National Institute on the case. To date, we have one pilot trial that looked at senolytic therapy and idiopathic pulmonary fibrosis, an age-related killer, and found modest improvements in walking distance and ability to rise from a chair. (Keep in mind though, the therapy in question combined quercetin and an anti-cancer drug dasatinib, a fairly well-studied combo which recently was found to cause brain damage in mice, so that could prove to be a red flag.) Another study looked at fisetin for older adults with osteoarthritis. The results are just now emerging and larger trials are being undertaken. 

Senolytics vs senomorphs?

It’s exciting times but still early days for the senolytic therapy. For instance, we don’t yet know how many senescent cells we actually want to get rid of. Some number of them appear to be valuable for wound healing, for example. Health care providers who work with these compounds generally recommend “pulsed” dosing, which means relatively high doses for 2 or 3 days and then pausing for the rest of the month to let the supplements clear the system. 

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Whatever the optimal dosing regimen turns out to be, I’m all for consuming generous amounts of the fruits and vegetables that naturally contain these compounds in more modest amounts. While we don’t have experimental proof that these foods act as senolytics, we do know they’re good for you for a hundred other anti-inflammatory and antioxidant reasons so why not load up? 

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And while you’re at it, make sure to fill your plate with foods and supplements that aren’t technically senolytics, but they are “senomorphs,” that is, they tamp down the inflammation generated by, among other things, those zombie cells. Into this category, I put turmeric/curcumin (especially when combined with piperine or black pepper extract), green tea, the cruciferous veggies, just for starters. 

Sweat senolytic therapy.

This probably won’t surprise you, but the animal research has established that exercise is an effective way to lower levels of cell senescence. I’m going to bet that it’s the same for people. Ditto for eating lean, clean and in moderation, and paying special attention to antioxidant veggies and fruits. 

The take-away.

Honestly, I view these this kind of therapy as a work-in-progress and I’m not yet recommending it for my patients as a protocol just yet, but as I mentioned above, eating the kinds of foods that promote help dismantle the senescent cells’ protective defenses is a good way to dip your toe in, and enjoy lots of other health benefits to boot. However, if you are interested in exploring it further, then by all means work with a knowledgeable health care provider. 

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For now though, what really excites me about the senolytics is proof of concept, and the concept itself—removing dysfunctional cells that accumulate with age—has opened an entirely new avenue of research. For decades, aging was seen largely as an inevitable outcome of time. Today, researchers are uncovering the biological mechanisms behind it piece by piece. We are at the beginning of an age where we can modify – slow down! – the aging process by pulling the right biochemical levers. 

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Whether that means we may soon be able to significantly expand our maximum lifespans, remains to be seen. But I think we’re fast assembling a toolbox of supplements, and maybe a few drugs, that will significantly increase our healthspan. That’s the real goal, being as robust as we can be, before it’s time to exit the stage.