Science Confirms that Heatwaves Don't Just Make You Feel Slower, They Actually Age You

4 min readNew research suggests that heatwave exposure speeds up biological aging.People with certain underlying health conditions may be most affected. There are a few theories on what could be behind this.The Earth is slowly getting hotter, and with that, heatwaves are becoming more frequent in many places. And while slogging through a heatwave is no fun for anyone, new research suggests that being exposed to extreme heat could do more than make you feel uncomfortable—it may be aging you.The study, which was published in the journal Cyborg and Bionic Systems, breaks down the impact heatwaves can have on your biological age, suggesting that it’s really important to do what you can to stay cool when temperatures soar. (Just a reminder: Biological age is how old your cells and organs appear to be, while chronological age is how long you’ve actually been alive.)There are a bunch of things that can impact your biological age, so it’s a stretch to say that heatwaves alone are impacting you in the aging department. But the findings raise several questions about why extreme temperatures may age you and what exactly you can do to combat this.Meet the experts: Rigved Tadwalkar, MD, consultative cardiologist and partner at Pacific Heart Institute in Santa Monica, California; Eric Ascher, DO, family medicine physician at Northwell’s Lenox Hill Hospital; David Benaron, MD, vice chair of research in the Department of Emergency Medicine at the University of Nevada, Reno School of Medicine.What did the study find?For the observational study, researchers analyzed data from 2,318 middle-aged and older adults in China. They specifically looked at participants’ biological age acceleration (the speed of aging in tissues, organs, and cells) and compared that to participants’ exposure to heatwaves from 2011 to 2015. The researchers used blood tests and health markers, like cholesterol levels, blood pressure, and inflammatory markers, in order to measure biological aging.They found that heatwave exposure was “significantly associated” with a higher biological age acceleration. This meant that the more people were exposed to extreme temperatures, the faster the speed of their biological aging process.In the most extreme cases, the researchers found that each heatwave incident was associated with up to six months of accelerated biological aging. People were the most at risk of experiencing this faster rate of biological aging if they were overweight or obese, lived in an urban area, or lived in southern or subtropical areas. Exposure to heatwaves was also linked to higher cholesterol levels and higher blood sugar levels.As a result, the researchers noted that “these results suggest that recurrent heatwave exposure may contribute to accelerated biological aging,” in the conclusion of their study.Why might heatwaves age you?Keep in mind, the study didn’t prove that heatwaves age you, but rather, it found a link between exposure to more heatwaves and a faster rate of biological aging. The study also didn’t separate people who rode through these heatwaves in air-conditioned comfort from those exposed to the heat 24/7. So while the study can’t point to a direct reason for the link, experts have a few theories.“Heat puts the body under sustained physiologic stress,” explains Rigved Tadwalkar, MD, a consultative cardiologist and partner at Pacific Heart Institute in Santa Monica, California. To keep your core temperature stable, your cardiovascular system needs to redirect blood toward your skin, he says. “The heart then works harder, and fluid balance becomes more difficult to maintain,” Dr. Tadwalkar says.The findings that people had higher cholesterol and blood sugar when they were repeatedly exposed to heatwaves are also telling, says Eric Ascher, DO, family medicine physician at Northwell’s Lenox Hill Hospital. “These are signs of your body struggling with its metabolism,” he says.While your body is navigating all of this, it also mounts a “systemic inflammatory and stress-hormone response” to try to regulate itself, says David Benaron, MD, vice chair of research in the Department of Emergency Medicine at the University of Nevada, Reno School of Medicine. Prolonged heat exposure for several days and nights can tire out the system and give an older cardiovascular and renal system less time to recover, Dr. Benaron says.All of these factors can age you, says Dr. Tadwalkar.One other thing to remember is that heatwaves also tend to go hand-in-hand with bad air quality days, Dr. Benaron adds. The study didn’t parse out which has more of an impact on biological aging, but he says it’s likely a combination. “Heat is causing real issues, and pollution is likely amplifying it,” he says.What’s the takeaway?Doctors say more work is needed in this space. But the findings aren’t great for people who have to live through heatwaves. “This research tells us we need better ways to protect everyone from heatwaves, like special heat warnings, cooler city designs, and community support,” Dr. Ascher says.Heat also tends to cause the most issues for people with underlying health conditions, like cardiovascular disease or diabetes, Dr. Benaron says. “Most of what I admit during a heat wave is not heat stroke,” he points out, but rather complications from existing health conditions like heart failure, diabetes, or kidney issues.“For the average person, the message is fairly practical: Pay attention to prolonged heat, especially if you have heart disease, diabetes, obesity, or take medications that can affect blood pressure, hydration, or temperature regulation,” Dr. Tadwalkar says.Dr. Benaron also urges people to take extreme heat seriously. “Take steps to avoid the heat and stay hydrated,” he says. “A few hours of air conditioning a day breaks the cycle—a library, a mall, a cooling center.” And, on days when air pollution levels aren’t great, he recommends that you “treat air quality as part of the same exposure.”Carina Hsieh, MPH, is the deputy features editor of Women’s Health. She has more than a decade’s worth of experience working in media and has covered everything from beauty, fashion, travel, lifestyle, pets, to health. She began her career as an intern in the fashion closet at Cosmopolitan where she worked her way up to Senior Sex & Relationships Editor. While covering women’s health there, she discovered her passion for health service journalism and took a break to get her Masters in Public Health. Post-grad school, she worked as a freelance writer and as The Daily Beast’s first Beauty, Health, and Wellness Reporter. Carina is an alum of the Fashion Institute of Technology and the Yale School of Public Health. She and her French Bulldog, Bao Bao, split their time between Brooklyn and Connecticut. She enjoys reformer Pilates, (slow) running, and smelling the fancy toiletries in boutique fitness class locker rooms.