Everyone in an ongoing study of healthy aging has to provide a DNA sample by spitting in a tube.
But Cloris Leachman’s the only participant who’s spit with the likes of the late actress Katharine Hepburn.
Leachman played Celia to Hepburn’s Rosalind in a 1950 Broadway production of Shakespeare’s “As You Like It.” Backstage one night, Leachman says, Hepburn challenged her to see who could spit the farthest.
“Mine just kind of dribbled down my chin,” but Hepburn’s flew, oh, 12 feet or so, Leachman, 85, recalled in a phone interview with msnbc.com from her Los Angeles home.
The Academy Award winner’s spit is a winner in the eyes of researchers, though. A few weeks ago, Leachman became one of about 1,100 people 80 and older who’ve enrolled in the “Wellderly” study of healthy aging. Their average age is 87; the oldest is 108.
Unlike other studies that focus on centenarians, Wellderly participants have never had cancer, heart disease or diabetes. Their minds are sharp.
Scientist Eric Topol and his team, who hope to enroll another 900 people in their study, are trying to unravel how this unique group of individuals has managed to stay so vital.
“Most of them, of course, are thin, and they’re active and socially networked,” says lead researcher Topol, chief academic officer of Scripps Health in San Diego, Calif., a nonprofit health system that treats a half-million patients each year at its hospitals, clinics and doctors’ offices. “They are just a series of remarkable people."
At 82, Leachman became the oldest person to compete in “Dancing with the Stars,” and she currently stars in the Fox TV comedy “Raising Hope,” for which she was nominated for an Emmy (she’s already won nine). Another woman in the study, the 108-year-old, traveled to Antarctica when she was 106. Others are writing books.
Leachman, the mother of five, grandmother of six and great-grandmother of one, attributes her health to her mindset and her diet. “I don’t think I’m my age,” she says. “I’m truly 6 years old.”
If Leachman is any example, having a sense of humor can add years to one’s life (and life to one’s years). While filming the Thanksgiving episode of “Raising Hope” last week, Leachman says, co-star Garret Dillahunt cracked her up so much that she wet her pants.
More from TODAY.com
6-year-old 'Rapunzel' chops off her hair for kids with cancer
Charlie Tillotson had never wanted to cut her hair, which had grown to more than two and a half feet in length, but all th...
- Extreme parenting: Who are we to judge?
- Fame, with brush: Check out Tony Bennett's surprising side gig
- Tamron's Tuesday trend: The wardrobe staple you need to have
- Kiefer Sutherland takes high road after Freddie Prinze Jr. slam
- 6-year-old 'Rapunzel' chops off her hair for kids with cancer
“I waddled away from the set,” she says. “I think I ruined the shot because I wasn’t supposed to be laughing.”
She laughs, and she eats healthfully. Leachman says she hasn’t touched red meat in 50 years.
It’s not just lifestyle that keeps the other study participants healthy, Topol says, noting that one 99-year-old man in the study smokes two packs of cigarettes a day.
The answers may be in their genes. Already, Topol says, the study has shown that participants carry the same common genetic variants linked to diseases of old age as other people, yet they’ve somehow escaped them.
“What this tells us is they’re gifted with these modifier genes,” Topol says.
In other words, although they carry genes that increase their risk of certain diseases, they also carry other, as-yet unidentified “guardian” genes that cancel out the bad actors. If the Wellderly researchers can figure out how the guardian genes protect against chronic diseases, Topol says, they might be able to come up with a drug that mimics that process.
To hone in on the guardian genes, Complete Genomics, a Mountain View, Calif., company, is partnering with Scripps on the Wellderly study and will sequence the whole genome of each participant at no cost, the two announced Monday. The data should be available by December. The information, uncoupled from the subjects’ names, will be made available to other scientists who need a healthy comparison, or control, group for genetic studies of the diseases of old age, Topol says.
Meanwhile, for Leachman, the show keeps going on. “They’re going to have to kill me with a lead pipe,” she says.
© 2013 msnbc.com. Reprints