What the latest research says about adding healthy years to your life

Death comes for us all. But recent research points to interventions in diet, exercise and mental outlook that could slow down aging and age-related diseases - without risky biohacks such as unproven gene therapies. A multidisciplinary approach involving these evidence-based strategies “could get it all right,” said Valter Longo, a biochemist who runs the Longevity Institute at the University of Southern California’s Leonard Davis School of Gerontology.

There’s a debate, however, about how much we can increase our longevity. All humans share 99.9 percent of their genes. This explains why even “super-agers,” born with tiny genetic differences that promote longevity, almost never surpass 110. (Jeanne Louise Calment of France was an outlier, living until the age of 122, the current record.) Some animals make it well beyond that mark, according to Jan Vijg, a molecular geneticist at the Albert Einstein College of Medicine. Scientists know just one way for humans to live 170 years like a giant tortoise: become a giant tortoise.

Some experts do find it likely that someone will set a record for our species by the end of this century. Statisticians have observed a “mortality plateau” for very old people; although the chance of dying in a given year goes up with age, the odds seem to stop increasing after 105. Beyond this plateau, it’s basically a coin toss every year: Heads you’ll see your next birthday, tails you won’t.

But the mortality plateau is often debated. Even if it’s true that the risk of death levels off, this won’t necessarily result in super-agers living longer than before. Susan Alberts, a Duke University primatologist, published a paper that compared the human rate of aging with other primates. The maximum human life expectancy has increased by about three months per year since the mid-1800s, but that can be explained by fewer early and midlife deaths. Alberts found that the rate of decline during old age has stayed the same, mirroring other species. She believes that maximum human life span could be extended by continuing to “avert early and midlife deaths,” which simply increases the pool of people who could live a really long time.

Time will tell who’s right regarding the life span of our species. What’s clear is that certain lifestyles help individuals live longer than they otherwise would - including the genetically blessed. Harvard researchers found that healthy habits add nearly 15 years of life expectancy. “That’s over $100 trillion in health-care savings,” said Harvard biologist David Sinclair.

Not enough Americans can access healthy lifestyles, however, and we’re getting sick and dying earlier across economic levels compared with other countries. People under 65 in the richest areas of the United States have higher mortality than those in the poorest areas of Europe, according to a study published  in September. “We’re going to pay if we don’t do something about this rising tide of disabled people,” said Judith Campisi, a biochemist at the Buck Institute for Research on Aging.

Findings from longevity research could support better health in old age, with fewer age-related diseases and disabilities. And interestingly, many scientists believe that a certain amount and type of stress can help, thanks to evolution. As Sinclair wrote in his 2019 book, “Lifespan”: “Our genes didn’t evolve for a life of pampered comfort. A little stress to induce hormesis once in a while likely goes a long way.”

“Hormesis” is a process in which various stressors — such as those related to diet and exercise — seem to activate genes that slow down cell growth and aging.

Using food to trick yourself

Stress that’s good for longevity can be caused by nutrition. Ideally, our ancestors enjoyed protein-rich red meat for peak energy and performance. But when hunting expeditions failed, people resorted to eating hardy plants. Today, our bodies still infer a state of scarcity if we consume lots of vegetables, switching on the longevity genes. Indeed, such a diet is associated with longer lives, according to the Harvard study. Becoming a full-fledged vegetarian probably isn’t necessary, but, to maximize what longevity experts call “healthspan,” at least 50 percent of protein should come from vegetable sources, Longo said.

He advises getting other proteins mostly from fatty fish while moderating your intake of starchy carbohydrates, such as pasta and potatoes. Research has shown that older people who routinely devour such carbs may be more likely to become cognitively impaired. Try to replace them sometimes with foods such as lentils or extra vegetables, which have more fiber and minerals than refined carbs, said Kris Verburgh, a nutrigerontologist and author of “The Longevity Code.”

Another signal of scarcity that seems to switch on longevity genes is the restriction of all foods, which has been shown by decades of animal studies to lengthen life span. Although water-only fasting over several days can be dangerous, “fasting mimicking” diets — very low-calorie five-day eating plans that trick the body into thinking it’s fasting while allowing some foods and nutrients — have been shown to be safer. Longo believes such diets “will play a major part in maximizing longevity.”

Research continues on various fasting regimens. In a preprint review, Matt Kaeberlein, a biogerontologist at the University of Washington, found limited evidence that avoiding food during specific windows of the day, without dropping overall calorie intake, increases life span in mice. When calories are reduced, some genetic strains of mice seem to benefit, but others actually die faster. Calorie restriction “could enhance longevity in some people while shortening lifespan in others,” Kaeberlein wrote.

“We’re beginning to find faults with some extreme diets,” Campisi said. The best approach, she said, “is dietary restriction without malnutrition.” The real benefit of fasting, she added, might simply come from losing weight. “Obesity is a risk factor for inflammation,” and chronic, low-grade inflammation can accelerate aging in a process known as inflammaging.

Sinclair eats just once per day, at dinnertime. “When you eat is perhaps more important than what you eat,” he said, referring to animal studies. “It’s easy to say mice aren’t humans, but there are some broad lessons.”

Exercising, but in moderation

Exercise can further simulate our ancestors’ stressful environments, some experts say, which can dupe your genes into extending your span of health. Just don’t do too much.

In August, the Mayo Clinic published research suggesting an optimal amount of exercise: People who played sports for 2.6 to 4.5 hours per week since the 1990s were about 40 percent less likely to have died than those who exercised less often. Cardio workouts may extend longevity by multiplying mitochondria, the “powerhouses” within cells. When scientists damage mitochondria in mice, the animals die faster, and mitochondrial dysfunction results in inflammaging in humans, Campisi said.

High-intensity interval training, or HIIT, may be particularly effective in adding to longevity. K. Sreekumaran Nair, a Mayo endocrinologist, found that 12 weeks of HIIT reversed many age-related differences in how older people synthesize proteins, buffering their mitochondria. Strength training may also partially reverse aspects of aging.

As with fasting, just don’t go overboard. “Some young guys want to do too much of everything,” Nair said. “There’s no data that working out beyond a certain level gives you better mitochondria.” Being very aerobically fit may reduce mortality risk, but the August paper suggests a Goldilocks sweet spot; exercising more than 10 hours per week was linked to shorter life spans. Previous research has shown an association between extreme exercise and health problems, such as premature aging of the heart.

Nair suggests doing 35 minutes of HIIT three days per week; doing two nonconsecutive days of strength training, focusing on core muscles, arms and legs, with three sets for each muscle group; and taking walks of 7,000 to 10,000 steps on the other two days. He also recommends trying to get at least three minutes of movement after every hour of sitting.

But keep in mind that these diet and exercise regimens can’t magically undo a lifetime of mistakes. A young person’s lifestyle “will echo for decades,” Sinclair warned.

Beyond diet and exercise

Sinclair noted another driver of longevity: long-term, loving relationships. In a nearly 80-year study, researchers found that the most important factor in a long, healthy life was having a close partner. Lynne Charnay, a 96-year-old actress who still performs onstage, attributes her longevity to marital bliss — a double dose of it. “I’ve had not one fabulous husband, but two!” Boxing regularly with her personal trainer in New York doesn’t hurt, either.

Another protective factor: optimism. In 2019, Boston University psychologist Lewina Lee found that optimism was associated with exceptional longevity. Take heart, Debbie Downers: Optimism can be cultivated through interventions. “While optimism is about 25 percent heritable,” Lee told me, “the rest is attributable to environmental influences.” That may partly explain why people entrenched in poverty, with little reason for optimism, die at much younger ages.

But residents of lower-income areas also have limited access to the heathy foods and opportunities cited above. That’s why experts on aging have called for policies that improve access to healthy lifestyles, especially as findings about exercise, nutrition and other anti-aging interventions continue to evolve, promising more years of health to those who can afford them.

“We’re still in the Wright brothers’ days of flight when it comes to longevity,” Sinclair said. “We still have a 747 and a Concorde to come, I hope, within our lifetimes.”