• Posted June 12, 2025

Accelerated Biological Aging Tied To Dementia, Stroke Risk

THURSDAY, June 12, 2025 (HealthDay News) — A hallmark of accelerated aging appears to be linked to an increased risk of dementia and stroke, a new study says.

Shorter telomere length in a person’s white blood cells is associated with the two brain diseases, researchers reported June 11 in the journal Neurology.

However, the link was not found in people with healthy lifestyle habits, researchers added.

“Our findings support the potential benefits of working to improve your risk factors such as maintaining a healthy weight, limiting alcohol and getting enough sleep and exercise in reducing the risk of age-related brain disease even in people who are already showing signs of damaging biological aging,” senior researcher Dr. Christopher Anderson, an associate professor of neurology at Harvard Medical School, said in a news release.

Telomeres are protective caps at the ends of chromosomes. Often compared to the plastic tips at the ends of shoelaces, telomeres serve a similar function — preventing chromosomes from unravelling.

Telomeres shorten every time cells divide, making them useful in estimating a person’s biological age, researchers said. Biological age reflects wear-and-tear from the stresses the body endures over time, and can differ greatly from the chronological age reflected by a person's birthday.

For this study, researchers analyzed genetic data for more than 356,000 people participating in UK Biobank, a large-scale health study in England, Scotland and Wales.

Researchers divided the participants into three groups based on whether telomeres in their white blood cells (leukocytes) were short, medium or long.

The team then compared telomere length to each person’s lifestyle habits, as well as whether they’d developed dementia, stroke or depression.

During an average seven years of follow-up, nearly 26,000 people developed at least one of these three age-related brain diseases.

People with the shortest telomeres had 5.8 cases of the three brain diseases per 1,000 person-years, compared to 3.9 cases per 1,000 for those with the longest telomeres. Person-years reflect both the number of people in a study and the amount of time each person spends in a study.

Overall, people with short telomeres were 11% more likely to develop one of the brain diseases, after accounting for other risk factors, results show.

They specifically had an 8% increased risk of stroke, 19% increased risk of dementia, and 14% increased risk of late-life dementia, the study says.

However, people with short telomeres didn’t have an increased risk if they made healthier lifestyle choices, like eating a good diet and exercising regularly, researchers found.

“These results suggest that healthy lifestyle behaviors could delay the aging of our cells and reduce the frequency of these diseases, especially in people who are greater risk,” Anderson said.

Researchers noted that the study can’t show a direct cause-and-effect link between telomere length and brain health, only an association between the two.

More information

The University of Utah has more about telomeres and biological aging.

SOURCES: American Academy of Neurology, news release, June 11, 2025; Neurology, June 11, 2025