Hot Flashes and Cold Plunges: The Next Evolution of Longevity

A look into the growing interest in longevity and what it means for men and women’s health.

The average person had a life expectancy of 32 years in 1900; today, it is over 73 years. Innovations in healthcare, better nutrition and sanitation, and improved living standards have led to global life expectancy doubling in just over a century. For comparison, in the 130 years prior to 1900, the average life expectancy only increased by 3.5 years.

Now, it is worthwhile to caveat that the average life expectancy is a statistical metric based on age-specific mortality rates. Simply put, it is an average and does not necessarily provide a prediction of an individual’s lifespan. So, while people on average are living longer, the human lifespan itself appears to be more static. A study on the length of life by the Journal of the Royal Society of Medicine found the median age of men born before 100 BC who died from “old age,” (i.e., not a violent death) was 72.

However, this too is being challenged. In 2019, in his New York Times bestselling book, Lifespan: Why We Age—and Why We Don’t Have To, Havard genetics professor David Sinclair wrote, “What’s the upward limit [of age]? I don’t think there is one. Many of my colleagues agree. There is no biological law that says we must age. Those who say there is don’t know what they’re talking about. We’re probably still a long way off from a world in which death is a rarity, but we’re not far from pushing it ever farther into the future.” Along a similar vein (no health pun intended), Bryan Johnson, a multimillionaire tech entrepreneur, is devoting his life to trying to become the first man not to die. In the process, he has founded two longevity companies, gained two million followers on Instagram, and released a Netflix documentary in January.

The interest in longevity and “living longer and better” has seemingly exploded in the past few years, driven by promising, albeit largely preclinical/early-stage, scientific research; an influx of capital; and growing consumer interest. Function Health, a company co-founded by Dr. Mark Hyman, which provides on-demand health testing for $499 per year, raised $300 million in its Series B funding round at a post-money valuation of $2.7 billion this past August, per Pitchbook. 

In truth, “longevity” seems to encompass both the ultra-wealthy engaging in biohacking in a pursuit to reverse aging and the everyday consumer looking for practical ways to take greater ownership over his or her health. I had the opportunity to get some perspectives on longevity from two HBS students: one who is actively building in the space, and one who is a “typical” longevity consumer. Andrea Gonzalez Corleto (MBA ‘26) is co-founding Lyv, a women-focused longevity startup, inspired by her own health journey and frustrations with the existing healthcare system. Julius Gruener (MBA ‘26) was an early follower of the longevity movement and has tried and tested many popular longevity best practices to improve his own health. 

Interest in Longevity 

Both Corleto and Gruener’s interest in longevity arose from a similar place: navigating a chronic illness. As Corleto sagely puts it, “for a lot of people, you start caring about your health when you realize your health is not optimal.”

Corleto began experiencing painful symptoms caused by endometriosis, a notoriously difficult-to-diagnose chronic illness that affects around 10% of women aged 15 to 44. She struggled to get a diagnosis, and even after finding a specialist, realized the visits were costly and out-of-pocket. “In that journey, I realized that the health care system is so reactive versus proactive. It took me so long to get a diagnosis, and even after I got diagnosed, it was still, ‘here’s a pill.’ I was like, what about supplements? What about my diet? What else can I be doing?”

Gruener was diagnosed with autoimmune liver hepatitis at the age of eight. As part of this diagnosis, he sees a doctor every six months and takes medication daily. “My disease is manageable, but it has forced me to live a healthier lifestyle, especially after a doctor told me I needed to monitor my alcohol intake in college.” This led him to conduct research on his own personal health. He read David Sinclair’s book and then began following other longevity influencers like Andrew Huberman and Peter Attia, who provided more evidence-backed studies around the impact of healthier lifestyle habits. “I used to have a philosophy ‘you can sleep when you’re dead.’ Now I don’t feel like I am fully functioning without a full eight hours,” Gruener says.  

Living Longer vs. Living Better 

So, what is longevity in practice? Again, it exists on a spectrum. At one extreme, longevity is about never dying — or at the very least, delaying aging. Bryan Johnson is going to great lengths to stop his biological aging, including receiving blood transfusions from his son, following strict lifestyle habits, and maintaining a hyperfocus on optimizing the human body. Zooming out from individual hacks to the population-level impact, Gruener is blunt. “Aging is the underlying cause of most deaths. For example, your risk of stroke is essentially a function of age. If we cured all cancer tomorrow, we’d gain roughly two years in life expectancy, but the debilitating effects of aging remain. Slowing aging by just 5%, we’d add about four years.”

However, for many people interested in longevity, it is less about living longer and more about living better. “It is lifespan versus health span,” as Corleto puts it. It is daily lifestyle choices that promote long-term wellbeing: sleeping seven to nine hours per night; reducing alcohol consumption; exercising regularly; incorporating cold plunges or sauna use; and being intentional about nutrition, supplements, and stress management. As Gruener describes, “for me, it is about … the practical things I can implement in my life … without going too far.”

The idea that we can play an active role in our health is an increasingly attractive one. McKinsey estimates the wellness category represents ~$500 billion in annual spend in the U.S. alone, growing at 4-5%. In addition, 84% of consumers say wellness is a “top” or “important” priority. 

But does one size fit all? Does aging look the same for both men and women? The truth is that that has been the implicit assumption for most longevity work to date. Studies have relied disproportionately on male animals or used mixed-gender groups without analyzing gender-specific responses. Part of this is due to the assumption that female hormone fluctuations introduce variability, making them harder to study. Men have a 24-hour hormone cycle, while for women, it is 28 days. 

The Women’s Health Opportunity 

However, women consistently live longer on average than men. Unfortunately, they also spend 25% more of their lives in debilitating health compared to men, which means “longevity” itself may be slightly different for women versus men. “Many men are trying to live longer, many women are just trying to live healthier,” Corleto describes. Unfortunately, as I covered last year, women’s health has been underfunded and under-researched — and longevity, historically, has been similar. Since its nascency, the longevity movement has been largely dominated by male voices.

To that end, Corleto is a pioneer in her own right. “We help women get to the root cause of their symptoms, identify areas of risk, and get clinician support through telehealth.” 

One of the root causes that must be understood is the role that hormones play. “Perimenopause is a crucial part [of] women’s lives, where your estrogen starts to decline ... When estrogen declines, you have a risk of cardiovascular disease, metabolic changes happen, bone density decreases.” As Corleto explains, “it affects both healthspan and lifespan.” 

Understanding the unique factors behind women’s aging and long-term health is critical for two reasons. First, women deserve more personalized solutions rooted in a deeper understanding of conditions that disproportionately affect them — from chronic illnesses to menopause — so they can live healthier, longer lives. Corleto has found this in her work already. “We thought it would mostly be women in their 40s and 50s, but younger women in their 20s and 30s have been really interested, too.”

Second, investing in women’s longevity has promising implications for men as well. As The Wall Street Journal reports, new scientific findings around the role that sex differences play in the aging process has made researchers increasingly excited about how learnings on treating and improving women’s aging could improve men’s aging as well. For example, could the expected lifespan of men depend on when their mother went into menopause? Jamie Justice, a gerontologist at the Wake Forest University School of Medicine, believes “that an important predictor of longevity in both females and males is the age at which their mothers go through menopause.” Researchers are also exploring the impact of women having two X chromosomes versus men’s only one, which releases proteins as the female mice age. This, too, could have implications for why women live longer.

It is exciting to see the growing momentum behind investing in women’s health both on a personal level and a societal one, especially if it means improving women and men’s quality of life. However, it’s worth noting that the longevity movement also faces its share of critics and unanswered questions, especially at its most extreme. Is it a narcissistic pursuit of immortality? Will only the ultra-wealthy benefit? Additionally, a lot of longevity research remains largely preclinical or in early stages. As we have seen, one-size may not fit all. These notes of caution are important ones to guide longevity leaders and consumers alike.

At its best, longevity empowers ordinary people to take a more proactive approach to their health, helping them to live better and feel better. This feels especially critical and promising for women, who spend more of their life in worse health. 

For me, it is like the adage goes: it is about adding life to the years, not just adding years to life. 

Meredith Nolan (MBA ’26) is originally from outside of Washington, D.C. She graduated from the University of Virginia with a BS degree in Commerce in 2020. Prior to the HBS MBA, Meredith worked in private equity in San Francisco on TPG’s Consumer team.