How quickly are you ageing?

What molecular ‘clocks’ can tell you about your health

Armed with an influx of cash and public enthusiasm, researchers are looking to improve how ageing is measured.

Heidi Ledford. Nature. February 25, 2025.

If the number of on-camera screams is any indication, Kim Kardashian’s first encounter with epigenetics was a thrilling one.

The reality-television star and her family shrieked and squealed in the season finale of The Kardashians in Los Angeles, California, last July as they each learnt the results of a commercial blood test that purportedly assessed their “biological ages”. Although Kardashian was 43, the placement of chemical markers on her DNA — her ‘epigenetic profile’ — matched that of a 34-year-old, according to the test. Her body, moreover, was ageing 18% more slowly than most people of her age.

“You should give yourself a pat on the back,” said Matthew Dawson as he relayed the results. (Dawson is chief executive of TruDiagnostic in Lexington, Kentucky, the company that sells the test.)

On the other side of the country, neuropsychologist Terrie Moffitt says she was “mortified” when she saw the segment. Moffitt, who works at Duke University in Durham, North Carolina, had spent decades with her colleagues collecting data from around 1,000 people to create the basis for one of the tests provided by TruDiagnostic. She had hoped that her work might one day inform medical decisions or provide a way for researchers to assess whether an anti-ageing treatment is having a positive effect on health. A stunt on a reality-TV show was not the kind of publicity she was aiming for. “I have a snob’s view of reality TV,” she adds.

Mixed feelings of enthusiasm and apprehension were common among researchers who spoke to Nature about efforts to develop tests that measure the impact of ageing on the body. With money pouring into the field and an unprecedented level of public attention and excitement, scientists are publishing a steady stream of papers on ways to measure how rapidly a person’s body is declining. Many of the measures look at chemical marks on DNA known as methylation, or at proteins or metabolites that can be found in the blood. These biological markers, or biomarkers, could prove incredibly useful as part of burgeoning efforts to develop drugs and other therapies that would forestall the negative effects of ageing and increase what gerontologists refer to as the healthy lifespan.

Often, however, test results that use these biomarkers are interpreted and presented without a full reckoning of the uncertainties that plague them. It’s a problem not just for commercial tests, but also for media articles and even scientific publications. “There’s a lot of confusion,” says Brian Chen, a molecular epidemiologist at California Pacific Medical Center Research Institute in San Francisco. “I’ve seen, in academia, scientists trying to promote and hype up ‘biological age’ and ageing research in general to generate more interest and funding.”

Chen and others worry about the risk of elevated expectations as scientists take on the long and arduous task of validating these tests. “Whether or not at the end of the day this kind of thing is going to be positive or negative for the field is hard to know,” says Matt Kaeberlein, chief executive at Optispan, a health-care technology company in Tukwila, Washington. “If you lose your reputation, that’s hard to get back.”

Marking time

For the moment, the field is on fire. In December 2024, the US Advanced Research Projects Agency for Health announced a programme to develop and validate biomarkers of ageing. Hevolution Foundation, a charity in Riyadh, has invested US$400 million in healthspan research. And organizers of XPRIZE Healthspan — a competition to find treatments for conditions associated with ageing — are planning a 7-year, $101-million global competition that is dedicated to improving healthspan.

A smorgasbord of tests to assess ageing already exists.

Episode 4236 - Feb 26 - Tiếng Anh - Bạn già đi nhanh như thế nào - Vina Technology at AI time

Vina Technology at AI time - Công nghệ Việt Nam thời AI

Episode 4236 - Feb 26 - Tiếng Anh - Bạn già đi nhanh như thế nào - Vina Technology at AI time