The Bible puts the human lifespan at 120 years, yet few people reach that milestone. As of 2025, there were 101,000 people at least 100 years old living in the U.S., and 722,000 in the world.
Ethel Caterham, born Aug. 21, 1909, and certified as the oldest living person by the supercentenarian research organization LongeviQuest, has said her secret to longevity was “never arguing with anyone! I listen and I do what I like,” CBS News reported.
Be that as it may, researchers say the secret may involve a bit more than that.
A study published in Cell Reports Medicine found protective genes, strong metabolic health, and a diverse microbiome likely all help.
The research was based on tissue samples taken from the body of María Branyas Morera, who died in 2024 at the age of 117 – at the time, the oldest person in the world. The researchers said her habit of eating three servings of yogurt a day likely contributed to the diversity of her gut microbiome and possibly her longevity.
“Aging is a process that can be managed, and it can go better or worse. It goes a lot better if you can develop a few simple habits and also avoid a couple of bad ones,” Turner Osler, professor emeritus at the University of Vermont, told The Food Institute.
“Most important is that you choose your parents carefully, because your genetics are responsible for about 50 percent of how long you will live. Of course, we don’t get to pick our parents, but there are things we can do that control the other 50 percent of our lifespan.”
6 Science‑Backed Habits That Boost Longevity
So what do experts recommend we do to increase the odds of living past the century mark?
FI surveyed several health experts to get their take. Here are the six things on which they could all agree:
- Eat enough fiber
- Don’t smoke or drink
- Don’t eat ultra-processed or fried foods
- Limit saturated fat intake
- Get enough exercise, including high intensity exercise and strength training, and avoid long bouts of sitting
- Get enough sleep
Lessons from Supercentenarians
Guinness World Records lists Jeanne Louise Calment of France as the oldest person ever to live. Born Feb. 21, 1875, Calment died at the age of 122 and 164 days.
Health experts say a sense of community is an underrated key to allowing people to live as long as Calment and Branyas Morera.
“Having a purpose in life and waking up to something every day is one of the most important ones,” added Dr. Meena Malhotra, founder of Heal n Cure Medical Wellness Center. “In some cultures, it’s called ‘ikigai.’ Also, when you have company, friends, a community and you are not alone – that can really be a gamechanger because you are keeping your brain and body active, socializing and learning new things.”
Malhotra also noted controlling insulin resistance is essential.
Madeline Salamon, founder and chief innovation officer at Credo, said one of the strongest “predictors of longevity is the amount and variety of whole plant foods people consume. Most people are unfortunately fiber deficient, even though fiber plays a major role in lowering inflammation, supporting gut health, and reducing risk for many chronic diseases.”
