The Secret to Living to 100? It’s Not Good Habits

If you want to live to your 100th birthday, healthy habits can only get you so far.

Research is making clearer the role that genes play in living to very old age. Habits like getting enough sleep, exercising and eating a healthy diet can help you stave off disease and live longer, yet when it comes to living beyond 90, genetics start to play a trump card, say researchers who study ageing.

“Some people have this idea: ‘If I do everything right, diet and exercise, I can live to be 150.’ And that’s really not correct,” says Robert Young, who directs a team of researchers at the nonprofit scientific organisation Gerontology Research Group.

About 25% of your ability to live to 90 is determined by genetics, says Dr. Thomas Perls, a professor of medicine at Boston University who leads the New England Centenarian Study, which has followed centenarians and their family members since 1995. By age 100, it’s roughly 50% genetic, he estimates, and by around 106, it’s 75%.

Knowing what enables some people to live very long lives has consequences for the rest of us. Ongoing research into very old age may help provide insight that could eventually be used to develop drugs or identify lifestyle changes to help people live healthier for longer, says Dr. James Kirkland, president of the American Federation for Aging Research.

Who makes it to 100

Centenarians make up a growing share of the U.S. population. There are about 109,000 centenarians living in the country in 2023, according to Census Bureau projections, up from about 65,000 10 years ago, thanks in part to decades of advances in medicine and public health.

Despite a decline in life expectancy, which dropped to 76.4 in 2021, Perls estimates that roughly 20% of the population has the genetic makeup that could get them to 100 if they also make consistent healthy choices.

Not only do centenarians live longer, but data suggest they manage to avoid or delay age-related diseases like cancer, dementia and cardiovascular disease longer than the general population. Among the New England Centenarian Study participants, 15% are “escapers,” or people with no demonstrable disease at the age of 100; some 43% are “delayers,” those who didn’t develop age-related disease until age 80 or after.

Chuck Ullman, who is 97 and lives in a retirement community in Thousand Oaks, Calif., says he is free of health problems—aside from a sore right shoulder from a recent electric biking accident—and has no desire to live to a particular age. He hopes to live as long as he feels good and can do the things he loves, such as woodworking, attending political discussion groups and getting dinner with some of his many friends.

“There are 350 residents here, and I have 350 friends,” Ullman says of his community. He also spends time with Betty, his wife of 77 years. “My objective is to enjoy each and every day that comes along.”

Genes that matter

Researchers have identified some genes and combinations of them that are associated with longevity, such as the presence of a variant of what’s known as the apolipoprotein E gene called e2, a trait thought to help protect against Alzheimer’s. They emphasise each trait is a small piece in a large, complicated puzzle, which can factor in socioeconomic status, race and ethnicity, and climate.

Living past 100 requires a combination of many genetic variants, each with a relatively modest effect, says Perls of the New England Centenarian Study.

Gene variants that offer protective qualities, such as repairing DNA damage, are especially beneficial, he says.

People who are curious about how long they might live should start by looking at their family histories. Your relatives’ lifespans are one of the strongest predictors of longevity, says Perls. Ullman, the 97-year-old, says his mother lived to 90.

If multiple members of your family have lived into very advanced age, “you’ve potentially won a much greater chance of having purchased the right lottery ticket,” says Perls.

Good habits

Neurologist Dr. Claudia Kawas has been tracking the habits of the “oldest old,” those older than 90, in Southern California since 2003, as part of a study at the University of California, Irvine. She and a team of researchers have found links between longevity and even short amounts of exercise, social activities such as going to church, and modest caffeine and alcohol intake.

“Super-agers,” or people over the age of 80 whose cognitive abilities are on par with those 20 to 30 years younger, reported having more warm, trusting, high-quality relationships with other people than cognitively normal participants, investigators at Northwestern University found.

“Keeping in good relationships could be one key to healthspan,” says Amanda Cook Maher, a neuropsychologist at the University of Michigan and lead author of the study.

Your outlook also matters. Harvard researchers identified a link between optimism and longer lifespans in women across racial and ethnic groups. Among the study participants, the 25% who were the most optimistic had a greater likelihood of living beyond 90 years than the least-optimistic 25%, according to the 2022 study published in the Journal of the American Geriatrics Society.

Jeanne Case, 100, says she has taken a glass-half-full approach to life.

She plans to outlive her colon and skin cancers and keep enjoying swing music and Mexican food as long as she feels physically and mentally well.

A day in her life can include walking a mile, conversing with her writing group or noshing on fish tacos with friends. The Irvine, Calif., resident has always exercised but also enjoys indulgences like cheesecake and lemon bars.

“I try not to let stress bother me,” she says.