longevity

Naked mole rats have extraordinarily long lifespans and are extremely resistant to cancer.

Photo credit: Meghan Murphy, Smithsonian's National Zoo

Rochelle "Shelley" Buffenstein has one of the world's largest, if not the largest, lab-dwelling colonies of the naked mole rat. (No one has done a worldwide tabulation, but she has 4,500 of them.) Buffenstein has spent decades studying the little subterranean-dwelling rodents. Over the years, she and her colleagues have uncovered one surprising discovery after another, which has led them to re-orient the whole field of anti-aging research.

Naked mole rats defy everything we thought we knew about aging. These strange little rodents from arid regions of Africa, such as Kenya, Ethiopia and Somalia, live up to ten times longer than their size would suggest. And unlike virtually every other animal, they don't lose physical or cognitive abilities with age, and even retain their fertility up until the end of life. They appear to have active defenses against the ravages of time, suggesting that aging may not be inevitable. Could these unusual creatures teach humans how to extend life and ameliorate aging?

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Eve Herold
Eve Herold is a science writer specializing in issues at the intersection of science and society. She has written and spoken extensively about stem cell research and regenerative medicine and the social and bioethical aspects of leading-edge medicine. Her 2007 book, Stem Cell Wars, was awarded a Commendation in Popular Medicine by the British Medical Association. Her 2016 book, Beyond Human, has been nominated for the Kirkus Prize in Nonfiction, and a forthcoming book, Robots and the Women Who Love Them, will be released in 2019.

A senior long jumper competes in the 80-84-year-old age division at the 2007 World Masters Championships Stadia (track and field competition) at Riccione Stadium in Riccione, Italy on September 6, 2007. From the book project Racing Age.

Angela Jimenez

What if a simple blood test revealed how fast you're aging, and this meant more to you and your insurance company than the number of candles on your birthday cake?

The question of why individuals thrive or decline has loomed large in 2020, with COVID-19 harming people of all ages, while leaving others asymptomatic. Meanwhile, scientists have produced new measures, called aging clocks, that attempt to predict mortality and may eventually affect how we perceive aging.

Take, for example, "senior" athletes who perform more like 50-year-olds. But people over 65 are lumped into one category, whether they are winning marathons or using a walker. Meanwhile, I'm entering "middle age," a label just as vague. It's frustrating to have a better grasp on the lifecycle of my phone than my own body.

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Matt Fuchs

Matt Fuchs is a health and science writer based in Silver Spring, Maryland. He has written on a variety of health topics, including profiles of older athletes defying their ages, for publications such as The Washington Post, The Washington Post Magazine, and Medium's The Startup. He is also a science fiction author. Follow him on Twitter, @fuchswriter.

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Summit County resident Gloria Breigenzer, 75, does a yoga headstand in the Rocky Mountains while her horse looks on.

(Photo credit: Thomas Breigenzer)


People are living longer in the world's richest countries, according to a recent Pew Report. Certain areas, in particular, have drawn the attention of researchers who study longevity because in those places, living to 100 is not unusual.

"If you want to live longer, shape your environment."

At 8000 feet up, Summit County, Colorado is a longevity hotspot. Surrounded by mountains that soar to more than 14,000 feet, the population of nearly 31,000 brags the highest expected lifespan in the United States, at 86.83 years. For comparison, the average life expectancy in the U.S. is 78.6 years.

So, what is it about living in Summit County that has brought about this high honor?

Despite popular belief, it's not about genes. Only about "20-30 percent of longevity can be predicted by genetics," longevity researcher Howard S. Friedman wrote in an email exchange. Friedman, a professor at the University of California at Riverside, co-authored a book about a famous study that followed participants for eight decades to learn what traits and factors contribute to a long life.

"About half is behavioral (including environmental)," Friedman says. "The rest is random (chance)." His longevity research is based on work that began in 1921 by Stanford University psychologist Lewis Terman. To discern the keys to longevity, Friedman and colleagues spent 20 years looking back at the lives led by the 1500 "gifted" 11-year old boys and girls who were born in 1910 and participated in Terman's study.

"We found that ambition, perseverance, and high motivation … predicted not only success but also longevity: Stressful job and hard work, long life!" Friedman says.

Longevity expert Dan Buettner agrees that an individual's environment is key. Buettner studies what he calls Blue Zones, where people "naturally live longer." But, unlike the five Blue Zones in the world -- Okinawa, Japan; Sardinia, Italy; Nicoya, Costa Rica; Ikaria, Greece; and Loma Linda, California — the majority of the Summit County population chose to move to the mountain towns that make up the region. Because Buettner believes that people can be taught to live longer, he sees Summit County as an instructive locale.

Like the Blue Zones, people in Summit County "do not pursue healthy lifestyles; [rather] it ensues," he says. "Blue Zones have the benefit of traditional patterns of eating and traditional rhythms of life. So they tend to be places where people walk to work, to a friend's house … [and] Blue Zone people eat the right food -- not because they have better individual responsibility or discipline; they simply live in an environment where beans, greens, nuts and grains are cheapest and most accessible."

"If you want to live longer," Buettner says, "shape your environment."

But an individual's environment can be affected by a number of factors, including socioeconomics, race, quality of and access to health care, as well as behavioral and metabolic risks. While the residents of Summit County smoke less and exercise more than those in regions with shorter life spans, they also have higher incomes and levels of education and lower unemployment.

"The healthiest individuals in The Longevity Project…lived meaningful, committed lives. They worked hard and played hard."

Gloria Breigenzer moved to Summit County 20 years ago with her husband. "We wanted to ski and ride horses up in the mountains," says Breigenzer. The 75-year-old still works part time as a hair dresser, goes to the gym every day, lifts weights and does yoga.

"I don't know why people don't want to get up and go out and work out and do stuff. I do," says the grandmother, who also exercises her rescue horse five days a week and for the past 15 years has done swing, country two step, and jazz dance in a group with her 77-year-old husband. She's also taking kiteboarding lessons and for the past two years has spent every afternoon studying Spanish.

Pete and Judy Rubin, both 65, retired to Summit County nearly two years ago from Cleveland. In Colorado, "socializing doesn't revolve around food," says Pete. "In Cleveland it always did…[Being outside] in summer or in winter is just easy. Skiing, on a bike, taking a hike, mowing the lawn, looking at a mountain instead of having someone else do it."

The Summit County approach resonates for researcher Friedman, who says that it's the "constellations of habits and patterns of living," that stood out most to him in his study. "Throw away your lists...The healthiest individuals in The Longevity Project…lived meaningful, committed lives. They worked hard and played hard. They were very persistent and responsible, and they were dedicated to things and people beyond themselves."

The following are some of the common denominators found in populations that live longer, including those who live in Summit County:

Plant-based diet: "Eat meat, no more than 5 times a month … [and] 95 percent of all the calories you take in should be whole plant-based foods," says Buettner.

Know your purpose: Buettner found that having and understanding your sense of purpose is worth up to seven years of extra life expectancy.

Have friendships: "You should have three to five friends who are healthy themselves who you can call on a bad day and they'll care," says Buettner.

Be on the move: Populations in zones where there is higher longevity "move naturally" as part of their day. It's not about diets. "No diet in the history of the world has worked for more than 5 percent of people after two years," says Buettner.

Relieve stress: "You should have some daily practices that help you downshift," says Buettner. It "could be taking naps, or meditation practice, or a habit of praying or a habit of doing happy hours."

Employ a family first rule: "Successful centenarians put their families first," explains Buettner. "And that means keeping your aging parents nearby, being seriously invested in your partner and if you have kids, you make them a priority."

It's these "key patterns of living [that] tend to make you both healthier and happier," says Friedman. "And health and happiness often then mutually reinforce each other."

Cari Shane
Cari Shane is a freelance journalist and corporate writer, skier, swimmer and Airbnb Superhost. Originally from Manhattan, Shane now lives carless in Washington, DC and writes for The Washington Post (newspaper and magazine), USA Today, OZY, Fodor’s, NextAve, and more.

Eliminating "zombie-like" cells, called senescent cells, may hold the key to slowing aging and its chronic diseases.

(© eshma/Adobe)


Imagine reversing the processes of aging. It's an age-old quest, and now a study from the Mayo Clinic may be the first ray of light in the dawn of that new era.

The immune system can handle a certain amount of senescence, but that capacity declines with age.

The small preliminary report, just nine patients, primarily looked at the safety and tolerability of the compounds used. But it also showed that a new class of small molecules called senolytics, which has proven to reverse markers of aging in animal studies, can work in humans.

Aging is a relentless assault of chronic diseases including Alzheimer's, cardiovascular disease, diabetes, and frailty. Developing one chronic condition strongly predicts the rapid onset of another. They pile on top of each other and impede the body's ability to respond to the next challenge.

"Potentially, by targeting fundamental aging processes, it may be possible to delay or prevent or alleviate multiple age-related conditions and many diseases as a group, instead of one at a time," says James Kirkland, the Mayo Clinic physician who led the study and is a top researcher in the growing field of geroscience, the biology of aging.

Getting Rid of "Zombie" Cells

One element common to many of the diseases is senescence, a kind of limbo or zombie-like state where cells no longer divide or perform many regular functions, but they don't die. Senescence is thought to be beneficial in that it inhibits the cancerous proliferation of cells. But in aging, the senescent cells still produce molecules that create inflammation both locally and throughout the body. It is a cycle that feeds upon itself, slowly ratcheting down normal body function and health.

Disease and harmful stimuli like radiation to treat cancer can also generate senescence, which is why young cancer patients seem to experience earlier and more rapid aging. The immune system can handle a certain amount of senescence, but that capacity declines with age. There also appears to be a threshold effect, a tipping point where senescence becomes a dominant factor in aging.

Kirkland's team used an artificial intelligence approach called machine learning to look for cell signaling networks that keep senescent cells from dying. To date, researchers have identified at least eight such signaling networks, some of which seem to be unique to a particular type of cell or tissue, but others are shared or overlap.

Then a computer search identified molecules known to disrupt these signaling pathways "and allow cells that are fully senescent to kill themselves," he explains. The process is a bit like looking for the right weapons in a video game to wipe out lingering zombie cells. But instead of swords, guns, and grenades, the list of biological tools so far includes experimental molecules, approved drugs, and natural supplements.

Treatment

"We found early on that targeting single components of those networks will only kill a very small minority of senescent cells or senescent cell types," says Kirkland. "So instead of going after one drug-one target-one disease, we're going after networks with combinations of drugs or drugs that have multiple targets. And we're going after every age-related disease."

The FDA is grappling with guidance for researchers wanting to conduct clinical trials on something as broad as aging rather than a single disease.

The large number of potential senolytic (i.e. zombie-neutralizing) compounds they identified allowed Kirkland to be choosy, "purposefully selecting drugs where the side effects profile was good...and with short elimination half-lives." The hit and run approach meant they didn't have to worry about maintaining a steady state of drugs in the body for an extended period of time. Some of the compounds they selected need only a half hour exposure to trigger the dying process in senescent cells, which can then take several days.

Work in mice has already shown impressive results in reversing diabetes, weight gain, Alzheimer's, cardiovascular disease and other conditions using senolytic agents.

That led to Kirkland's pilot study in humans with diabetes-related kidney disease using a three-day regimen of dasatinib, a kinase inhibitor first approved in 2006 to treat some forms of blood cancer, and quercetin, a flavonoid found in many plants and sold as a food supplement.

The combination was safe and well tolerated; it reduced the number of senescent cells in the belly fat of patients and restored their normal function, according to results published in September in the journal EBioMedicine. This preliminary paper was based on 9 patients in an ongoing study of 30 patients.

Kirkland cautions that these are initial and incomplete findings looking primarily at safety issues, not effectiveness. There is still much to be learned about the use of senolytics, starting with proof that they actually provide clinical benefit, and against what chronic conditions. The drug combinations, doses, duration, and frequency, not to mention potential risks all must be worked out. Additional studies of other diseases are being developed.

What's Next

Ron Kohanski, a senior administrator at the NIH National Institute on Aging (NIA), says the field of senolytics is so new that there isn't even a consensus on how to identify a senescent cell, and the FDA is grappling with guidance for researchers wanting to conduct clinical trials on something as broad as aging rather than a single disease.

Intellectual property concerns may temper the pharmaceutical industry's interest in developing senolytics to treat chronic diseases of aging. It looks like many mix-and-match combinations are possible, and many of the potential molecules identified so far are found in nature or are drugs whose patents have or will soon expire. So the ability to set high prices for such future drugs, and hence the willingness to spend money on expensive clinical trials, may be limited.

Still, Kohanski believes the field can move forward quickly because it often will include products that are already widely used and have a known safety profile. And approaches like Kirkland's hit and run strategy will minimize potential exposure and risk.

He says the NIA is going to support a number of clinical trials using these new approaches. Pharmaceutical companies may feel that they can develop a unique part of a senolytic combination regimen that will justify their investment. And if they don't, countries with socialized medicine may take the lead in supporting such research with the goal of reducing the costs of treating aging patients.

Bob Roehr
Bob Roehr is a biomedical journalist based in Washington, DC. Over the last twenty-five years he has written extensively for The BMJ, Scientific American, PNAS, Proto, and myriad other publications. He is primarily interested in HIV, infectious disease, immunology, and how growing knowledge of the microbiome is changing our understanding of health and disease. He is working on a book about the ways the body can at least partially control HIV and how that has influenced (or not) the search for a treatment and cure.

A healthy middle-aged couple enjoying a hike. (Shutterstock)

(Shutterstock)


[Editor's Note: This video is the fourth of a five-part series titled "The Future Is Now: The Revolutionary Power of Stem Cell Research." Produced in partnership with the Regenerative Medicine Foundation, and filmed at the annual 2019 World Stem Cell Summit, this series illustrates how stem cell research will profoundly impact human life.]

Kira Peikoff
Kira Peikoff is the editor-in-chief of Leaps.org. As a journalist, her work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and son.