SOLNA, Sweden — Many people have seen older adults who look like they’re in better shape than people half their age. In a scientific sense, these individuals have a lower biological age than their actual chronological age. Essentially, it’s the scientific explanation for the saying, “Age is only a number.” However, the aging pendulum swings both ways, and plenty of people are actually older biologically than they are chronologically. Researchers from the Karolinska Institutet have found that those with a higher biological age than their actual chronological age display a notably higher risk of both stroke and dementia, particularly vascular dementia.
This project, led by associate professor Sara Hägg and Jonathan Mak, a doctoral student at the Department of Medical Epidemiology and Biostatistics, also found that the increased risk persists even after considering other risk factors such as genetics, lifestyle, and socioeconomics.
As all humans age and grow older, the risk of chronic diseases like cancer, cardiovascular disease, and neurodegenerative disorders goes up. Traditionally, scientists and doctors alike have focused heavily on chronological age, or the number of years a person has been alive, as a rough measure of biological age.
“But because people age at different rates, chronological age is a rather imprecise measure,” says Hägg in a university release.
So, to gauge biological age’s link to disease, study authors made use of data originally collected by the U.K. Biobank. In all, they assessed a group encompassing 325,000 people who were between 40 and 70 years-old at the time of their first health measurements.
The team calculated biological age using 18 biomarkers. Some of those biomarkers included blood lipids, blood sugar, blood pressure, lung function, and BMI. Next, the research team analyzed the relationship connecting these biomarkers and the risk of developing neurodegenerative diseases like dementia, stroke, ALS, and Parkinson’s disease over the course of a nine-year period.
When they compared high biological age to actual, chronological age, it was linked to a significantly higher risk of dementia, particularly vascular dementia, and ischemic stroke (a blood clot in the brain).
“If a person’s biological age is five years higher than their actual age, the person has a 40 percent higher risk of developing vascular dementia or suffering a stroke,” Mak explains.
Researchers stress that this work was observational in nature, and thus cannot establish a casual relationship. However, these findings suggest that slowing down the body’s aging processes in terms of measured biomarkers may make it possible to delay or impede disease onset.
“Several of the values can be influenced through lifestyle and medications,” Hägg adds.
These findings are especially noteworthy because this project featured such a large group of people. Thus, this work can be broken down into smaller pieces in order to potentially capture less common diagnoses such as ALS. Importantly, ALS risk also increases with biological age, but no such relationship was seen regarding Parkinson’s disease.
“We already know that Parkinson’s disease is a bit unique in other contexts as well, for example, when it comes to smoking,” Hägg concludes.
Moving forward, researchers now plan to investigate the connection between biological age and various other diseases like cancer.
The study is published in the Journal of Neurology, Neurosurgery and Psychiatry.
You might also be interested in:
- Following these 8 healthy habits slows down aging by up to 6 years
- Young adults facing financial ruin as they care for aging loved ones
- ‘Biological age’ eclipses birthdate when it comes to telling how long someone will live