This is what we’ve learned about defying the passage of time from worms, fruit flies, and centenarians. Tom Perls met two persons who would impact his life in the early 1990s. Perls was visiting Boston’s Hebrew Rehabilitation Center for Ageing as a gerontology fellow at Harvard Medical School and needed to examine a couple of patients who happened to be over 100 years old. However, he was unable to locate them in their respective rooms. One patient, a 103-year-old woman, was eventually located.
She was engrossed in her piano practise of Chopin and Mozart. Perls’ other patient, a 101-year-old former tailor, was spotted fixing his housemates’ garments in the occupational health unit. Perls, who is currently stationed at Boston University, says, “They really startled me, and that’s when the epiphany happened. “These persons appeared to be ageing very slowly in comparison to others.” He vowed to find as many more centenarians as he could in order to figure out their longevity secrets. The New England Centenarian Study, the world’s largest study of very elderly people, grew out of the effort.
Centenarians are no longer as uncommon as they once were. According to the Office for National Statistics, there were 15,120 centenarians in the UK in 2020 (almost double the number in 2002). However, receiving a birthday letter from the Queen is still a fantastic achievement. We spoke with longevity specialists about the science that could help us all get there, as well as the ageing myths you should be aware of.
Related: people who walk miles or exercise regularly can also be healthy.
Myth: Aging has an evolutionary purpose
We need to understand why our bodies age in the first place before we can figure out how to slow (or even stop) it. However, Aston University biologist Cathy Slack claims that scientists are still undecided. “There’s no benefit to ageing from a purely theoretical standpoint,” she argues. We used to think that ageing was caused by a buildup of reactive oxygen species (free radicals) that caused molecular damage, but new study indicates that this isn’t the case.
According to Slack, the current most accepted view is that ageing is an unintended consequence of biological mechanisms that encourage growth and reproduction in our youth. The same systems that formerly made us fitter begin to make us sicker after a certain point, and the body is unable to switch them off. The ‘hyperfunction’ theory of ageing is what scientists term it. “It’s like a faucet that’s been left open,” Slack adds. “You need to fill the bath, but if you leave the tap running, the water will overflow, flooding your bathroom.”
Myth: As you become older, your health will deteriorate
The musician and the tailor were not anomalies, according to Perls’ research of centenarians. People who live to be 100 are not only long-lived, but they also escape significant illness until the end of their life. According to the medical histories of his participants, there are three types of centenarians. Around 43% are ‘delayers,’ meaning they don’t show signs of ageing until they’re in their seventies. Another 42 percent are ‘survivors,’ who are in their 60s and 70s and have a chronic condition that does not kill them.
The remaining 15% or so are ‘escapers,’ or people who are 100 years old or older and have no clinically detectable disease. True, age is a significant risk factor for a variety of chronic ailments, including heart disease, dementia, and diabetes. Perls, on the other hand, feels that the old saying that “the older you get, the sicker you get” is untrue. He chooses to think of it this way: “the older you grow, the healthier you’ve always been.”
Myth: There’s nothing you can do to keep yourself from dying
According to Perls, centenarians, especially super-centenarians (those who live to be 110 years old), are likely to have genetic variations that protect them from age-related disease. When it comes to lifespan, though, heredity isn’t the whole picture. In fact, research reveals that genes account for only around 25% of the variation in human lifespan.
The majority of the money is spent on health-related behaviours and the environment. Perls points to California’s Seventh-Day Adventists as an example. This Christian denomination’s members live up to a decade longer than the general population of California. It could be because they don’t smoke, drink, or consume meat.
Perls believes that most of us can live into our nineties if we start living a healthy lifestyle in our forties. Frank Hu, a nutritional epidemiologist at Harvard’s T.H. Chan School of Public Health, agrees. His study, which was published in the British Medical Journal in 2020, discovered five lifestyle characteristics that could give you an extra ten years.
People who never smoked, drank in moderation, had a healthy BMI, exercised for 30 minutes a day, and ate a high-quality diet increased not just their life expectancy but also the number of years they lived free of significant diseases including diabetes, heart disease, and cancer. According to Hu, the findings give cause for optimism. “You don’t have to go vegan or run a marathon to be successful.” Small changes to your diet and lifestyle could help you live longer.
Related: Insects are in increasing demand for protein in pet food.
Stopping senescence may be crucial to living a long life
Other research on longevity focuses on a type of cell that accumulates in our tissues as we age. These cells are no longer reproducing, but they are also refusing to die. Biologists used to reject these zombies, known as senescent cells, as having little bearing on health or disease. However, some experts now believe that altering them could be the key to a healthier ageing process.
Senescent cells exude inflammatory substances that damage tissue and prevent surrounding cells from carrying out their regular functions, according to biochemist Judith Campisi of the Buck Institute for Research on Aging in California. As a result, removing them from the body may help to slow down the ageing process.
Mice administered senolytics, which selectively kill these senescent cells, lived longer than normal at James Kirkland’s research at Mayo Clinic in Minnesota, and showed delayed onset of various age-related illnesses. Since then, several biotech companies, including Unity Biotechnology, have turned their attention to senolytics as a potential fountain of youth.
However, not everyone is persuaded. Perls warns, “I don’t think they’re going to get a lot of people to 100.” Senolytics, on the other hand, he believes, could be useful in preserving health in later age. He’s currently looking into senescent cells in his centenarians (and their relatives) to discover if individuals who age exceptionally well have a lesser load of cellular undead.
Fruit flies and worms can teach us a lot
Although research on extremely elderly people is critical for understanding how to reverse ageing in humans, we may also learn a lot about lifespan from seemingly unrelated animals like worms and insects. “When I tell people I work with fruit flies, they’re usually surprised,” Slack adds. “However, we now see that animals of very different species age in remarkably similar ways.
“Slack’s study focuses on insulin signalling and how it affects the ageing process. “We know that this signalling route permits the animal to grow larger and reproduce when it’s young,” Slack explains. However, she’s discovered that blocking this mechanism causes the laboratory critters to live far longer than they should.
Slack claims she can extend the life of a fruit fly by up to 20% with no negative consequences other than the organism’s inability to reproduce. Her research builds on a nearly 30-year-old discovery in which scientists deleted the insulin-signaling receptor from a worm and increased its lifetime by a factor of two. However, additional research is needed to see if these discoveries can be applied to humans and how you may change critical signalling networks without harming them.
Related: Fruits used to control blood pressure, new research
Fasting could help you live longer
Scientists can use genetic editing tools to make flies and worms live longer, but they also know an easier way to extend the lifespan of organisms: hunger. Clive Mc Cay, a scientist, discovered in the 1930s that rats on highly restricted diets survived up to 33% longer than previously assumed.
More recent research from the Salk Institute in California compared rats on a standard diet with those who had eaten 30% fewer calories than normal since middle age. When the investigators looked at cells from various body regions, they discovered that cells from older dieting rats looked quite similar to those from relatively younger animals.
Such research suggests that calorie restriction in people could result in similar increases in lifespan and possibly other health consequences. For the most part, though, it is not an appealing or prudent endeavour. Intermittent fasting diets (such as the 5:2), in which people eat normally for the majority of the time except for a couple of days on a low-calorie diet, are popular among dieters.
Some experts believe these approaches may help people live longer, but the proof is still lacking. “Intermittent fasting is a terrific strategy for certain people to maintain a healthy weight,” Slack explains. “However, it has to be seen whether it will prove useful in terms of living longer.”
Anti-aging medications could be available soon
It would be much easier to simply take a drug to extend your life – and, hopefully, your health. Some medications have been identified by scientists to be effective. Rapamycin, an immunosuppressant, appears to lengthen the lifespan of mice. Metformin, a diabetes medicine, also appears to help lab animals live longer.
Metformin has been linked to improved (unrelated) health outcomes, such as fewer heart attacks and cancer diagnoses, in human trials of persons taking the medicine for type 2 diabetes. In addition, a 2014 study found that diabetic individuals who took metformin lived longer on average than non-diabetic patients who did not take the medicine.
As a result of this hopeful research, there have been stories of people taking metformin off-label with the hopes of living longer. However, there is still insufficient clinical proof that this drug would be beneficial to healthy people. Researchers, on the other hand, are fascinated. The Targeting Aging with Metformin (TAME) experiment, conducted by Nir Barzilai at the Albert Einstein College of Medicine in New York, received FDA approval in 2019.
TAME will look into whether taking metformin increases the amount of years someone can stay healthy (without stroke, heart failure, dementia, cancer or death). “It’ll be fascinating to see what happens,” Slack says. “Metformin is really inexpensive. We also need to keep in mind that any medicine that helps people age well should be available to everyone.”