Prohibition. World War II. The Civil Rights Movement. The first man on the moon.
Those reaching their 100th birthday this year have lived through numerous pivotal historical events. When they were born in 1922, many homes didn’t have electricity, and the average American made $3,200 a year. White women had just received the right to vote, and it would be decades before black women received that same right.
Sept. 22 is National Centenarian Day, a day to celebrate those who have reached their 100th birthday, termed centenarians.
As of 2021, the United States had 97,914 centenarians, and an estimated 573,000 centenarians live across the world, the United Nations estimates.
Dr. Thomas T. Perls, MD, director of the New England Centenarian Study at Boston University, said living to 100 is based, in part, on possessing a series of genetic markers but mainly comes from living a healthy lifestyle. Perls and other researchers have identified genetic markers they believe have an effect on aging. It’s not one specific genetic marker, he said, but the combination of many genes that allows people to live well past the 100-year mark.
“It’s kind of like winning the lottery,” he said. “Getting the right combination is really rare, and those combinations get rarer and rarer with older and older ages, and that’s why there’s far fewer of those individuals.”
These genes explain familial aging trends, where multiple siblings reach well past the 100-year mark. About 50% of the 3,000 participants in the New England Centenarian Study have a family member who is also a centenarian, but Perls said the real number may be much higher in the future because in the early 1900s, many people died from what are now preventable diseases.
The genes also play more of a role as people grow older. Before age 90, living a healthy lifestyle is the main way people prolong their lives.
“If you do everything right, I think the average person should be able to get to about 90,” Perls said. “I think that’s what our average set of genes is capable of achieving for us, which is really rather amazing.”
Loma Linda University studies aging and the onset of disease in the Seventh Day Adventist population, a Christian denomination that emphasizes health by advocating for a healthy diet (in many cases a lack of processed foods, advocating for vegetarianism and eating in moderation), exercise and sufficient water intake. Followers don’t drink alcohol or use tobacco or drugs, and instead devote a lot of time to family and religion, which may provide an outlet for stress.
For Seventh Day Adventists, the average life expectancy reaches into the late 80s, about a decade older than the rest of the population. This research shows the impact a healthy lifestyle can have on life expectancy.
People in general, though, are living longer than they used to. A century ago, the average American lived to 60, according to data from the University of California Berkeley. Now, people live to 76 on average.
The number of centenarians is also increasing. Since the New England Centenarian Study began in the mid-1990s, the population of centenarians in the United States has doubled.
[Since] the mid-1990s, the population of centenarians in the United States has doubled.
Perls said this is due to improvements in medicine. He foresees this number will continue to increase as the Baby Boomer generation grows older.