832. Could Ozempic slow—or even reverse—aging? We take a closer look at the science behind the buzzy headlines.
Could Ozempic slow—or even reverse—aging? We take a closer look at the science behind the buzzy headlines.
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Find a full transcript here.
Could the weight loss drug everyone is talking about also be the fountain of youth? A new study just found that people taking semaglutide rewound the biological clock by an average of 3 years. But before we start adding ‘longevity’ to the drug’s resume, we need to talk about what those numbers actually mean—and who they apply to.
Welcome to the Nutrition Diva podcast, where we take a closer look at nutrition news, research, and trends and answer your food and nutrition questions. I’m your host, Monica Reinagel, and today I want to address some of the buzzy headlines you may have been seeing about the prescription drug semaglutide—better known by brand names like Ozempic and Wegovy—and its supposed anti-aging effects.
The study that sparked these headlines was a 32-week, double-blind, placebo-controlled randomized trial. That’s the gold standard for testing whether a treatment has real effects. But here’s an important detail right up front: the study participants were not representative of the general population–or the vast majority of people who actually use these medications.
This study involved adults living with HIV, and the trial was originally designed to see how semaglutide might affect lipohypertrophy. This is a condition that sometimes affects HIV patients and causes an abnormal accumulation of fat in certain areas of the body. And semaglutide was found to be quite effective in managing this particular condition.
But, after the trial was over, researchers used some of the of the blood samples collected during the trial to do what’s called a "post-hoc analysis,” where they go back and take another look at the data or samples they’ve already collected to see if they can find any new or interesting patterns.
That might mean separating out subgroups of participants (say, only women, or only people over 50) and analyzing the data for them separately to see if the results look any different in those narrower populations. Or it might mean looking at outcomes that weren’t originally part of the experimental design.
Now, because these weren’t the original questions the study was designed to answer, it’s more likely that any results you come up with are due to chance. So, post-hoc findings can be interesting and worth following up on—but they really need to be confirmed in a new study before we can have much confidence in them.
In this case, the post-hoc analysis had to do with assessing the effects of semaglutide on the subjects’ biological age, using a variety of measures. And they found that semaglutide appeared to slow the pace of aging by about 9%. In fact, the participants measured about 3 years younger at the end of the study than they did at the beginning. More specifically, the results suggested that the drug shaved 5 years off the biological age of their brains and more than 4 years off their cardiovascular system. Improvements were also seen in kidney and liver function.
These are obviously pretty exciting findings–although I do want to note that this study has been made publicly available as a “preprint,” meaning that it has not yet undergone peer review or been accepted for publication by an established scientific journal. Nonetheless, that corner of the internet that I think of as the “longevity bros” is all over this–heralding GLP-1s as the next antiaging superdrug.
So, how could a drug like semaglutide, which was developed to treat diabetes and is now widely used for weight loss, possibly influence biological aging? The most likely explanation is that it’s acting on some of the same pathways we already know contribute to age-related decline. Specifically, semaglutide treatment has positive effects on inflammation, visceral fat, and insulin sensitivity--all of which are plausible mechanisms for slowing or reversing some aspects of biological aging.
But before we declare aging a thing of the past, I think we need to step back and consider some of the fine print.
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When scientists talk about “biological age,” they’re usually referring to how old your body seems to be based on certain biomarkers, compared to your chronological age, or the number of birthdays you’ve had.
In this case, researchers used something called epigenetic clocks. These tests can detect shifts in biological aging trajectories over relatively short periods, which is why they’re popular in anti-aging research. These epigenetic clocks measure patterns DNA methylation at specific sites along your genome. Over time, these patterns change in ways that tend to correlate with aging and disease risk.
There are several different clocks, and the study used a whole panel of them and all of them suggested significant positive (that is, anti-aging) effects. But there are a few important caveats:
First of all, epigenetic clocks are surrogate markers, not direct measures of healthspan or lifespan. A clock might say you’re “three years younger,” but that doesn’t prove you’ll live three years longer—or have fewer health problems.
Secondly, the various tests are not well standardized. Different research groups and commercial labs use different algorithms and may get different results on the same person.
And finally, we know that certain DNA methylation patterns tend to correlate with higher or lower disease risk and mortality. That’s why these clocks can be predictive of your health trajectory. But we don’t yet know whether making those numbers “better” (as was the case in this study) will necessarily translate into better health or a longer life.
So while these clocks are exciting tools for researchers, we can’t really use them to prove that something actually slows—or reverses—human aging in a meaningful, real-world way.
The other bit of fine print has to do with the specific group that was studied. All of the participants were people living with HIV. Now, as you’re probably aware, we have made great strides in the treatment of HIV infection. With proper medical management, people with HIV can expect to lead largely normal lives with a life expectancy typical of others their age.
But, even with well-controlled infection, people living with HIV do tend to experience accelerated biological aging. This is thought to be due to immune system activation and chronic inflammation, and it means they are more prone to age-related problems, like heart disease, and cognitive decline—and these often show up earlier than they would in the general population.
Because of this, people with HIV provide a unique opportunity for testing potential anti-aging interventions. If something can slow—or even reverse—measures of biological aging in a population that experiences accelerated aging, it’s a very hopeful sign.
But that also means the results don’t necessarily apply to everyone else. In this case, semaglutide may have been able to normalize an abnormal aging trajectory. But that’s a lot different than turning back the clock for people who are aging at a more typical pace. And in fact, in their press release, the researchers mention that “another GLP-1 trial of generally healthy adults saw no age reduction,” apparently referring to another unpublished analysis.
And this is why we need to slow down and separate the science from the spin. Semaglutide may indeed hold promise as an anti-aging therapy, but to really prove that it works as well or better than other better-established (not to mention, cheaper) approaches, we’d need a lot more research. In other words: this is intriguing science, but, as is often the case, the headlines claiming that Ozempic can make you 3-5 years younger are way out ahead of the actual evidence.
That said, controlling inflammation, reducing visceral fat, and improving metabolic functions are all worthwhile goals for healthy aging–and you don’t necessarily need a prescription drug to pursue them. In fact, the safest, most reliable, and most accessible tools we have are the ones you’ve heard me talk about many times before:
And when you see those clickbait headlines claiming that any drug, food, or supplement “reverses aging,” remember to ask: Who was studied (and by whom)? What was measured? And does that actually translate into better health or a longer life?
If you have a question you’d like me to answer, you can email me at nutrition@quickanddirtytips.com. If you’d like to find out about having me speak at your next live or virtual event, you can learn more at wellnessworkshere.com
Nutrition Diva is a Quick and Dirty Tips podcast. Holly Hutchings is our Director of Podcasts. Steve Riekeberg is our audio engineer, Morgan Christianson heads up Podcast Operations & Advertising. and a special welcome to Rebekah Sebastian, our new Manager of Marketing and Publicity. Thanks also to Nat Hoopes for his support and most of all thanks to you for listening!