In brief
- The research showed that biological age can be a stronger predictor of dementia risk than chronological age.
- According to a February 2025 report by the National Institutes of Health, more than 6 million Americans are living with dementia.
- Experts say tracking biological age helps improve the understanding of health and aging, while also identifying early risks of diseases such as dementia.
Aging faster on the inside—even if you’re still young on the outside—could raise your risk of dementia, a new study from Zhengzhou University in China found.
The research showed that biological age, or how well the body is functioning, can be a stronger predictor of dementia risk than chronological age.
The study, published on Wednesday in Neurology, the journal of the American Academy of Neurology, used data from the UK Biobank and tracked 280,918 people with an average age of 57 over a 14-year period.
It found that faster biological aging was linked to a 14% to 15% higher risk of developing dementia.
“With the rising impact of dementia around the world, identifying risk factors and implementing preventive measures is essential,” lead researcher Dr. Yacong Bo said. “While none of us can change our chronological age, we can influence our biological age through lifestyle factors such as diet and exercise.”
To assess biological aging, Chinese researchers used two metrics: Klemera–Doubal Method Biological Age (KDM-BA), which uses blood test results; and PhenoAge, which draws on clinical data tied to aging and mortality.
For each increase in the rate of biological aging, as measured by KDM-BA and PhenoAge, the risk of dementia rose.
“These brain structure changes explain some, but not all, of the association between advanced biological age and dementia,” Bo continued. “These results support the hypothesis that advanced biological age may contribute to the development of dementia by causing a widespread change in brain structures.”
More than 6 million Americans are living with dementia, which causes about 100,000 deaths annually, according to a February 2025 report by the National Institutes of Health.
While dementia has declined 13% per decade due to better education, heart health, and lifestyle, the total number of cases is rising as the population ages, increasing pressure on the healthcare system.
In 2020, the number of people worldwide with dementia stood at 55 million, according to the non-profit Alzheimer’s Disease International. By 2030, the number is expected to reach 78 million, and by 2050, it is projected to reach 139 million.
Age is often seen as just a number on a calendar, with chronological age referring to the number of years one has been alive. In contrast, biological age reflects how well your body is functioning relative to that number.
Experts say that tracking biological age helps improve our understanding of health and aging, while also identifying early risks of diseases like dementia.
“Focusing on biological age offers a more accurate, personalized understanding of an individual’s health,” Dr. John Thomson Smith told Decrypt. “In clinical settings, this could guide more tailored treatment plans, while in consumer wellness, it could provide personalized wellness recommendations to improve quality of life and longevity.”
For Smith, senior medical advisor at AI-powered longevity research network Rejuve AI, targeting biological age can transcend one-size-fits-all care, providing a targeted approach to identify and reduce risks, such as dementia, early.
“Biological age reflects the true state of an individual’s health, based on a variety of factors such as genetics, lifestyle choices, and environmental influences,” Smith said.
Researchers found that changes in gray matter volume, which is responsible for memory, decision-making, and other key functions, along with cortical thickness and surface area, help explain the link between faster biological aging and the development of dementia.
As scientists race to find cures for dementia, they are exploring novel approaches, including gene therapies, advanced drugs, and artificial intelligence for early detection through brain imaging and biological age tracking.
“The most exciting aspect of these drugs is their multi-system benefits,” Professor of cardiology and medicine at Northwestern University, Dr. Sadiya Khan, previously told Decrypt. “They target not just diabetes, heart health, or brain health, but all these areas simultaneously.”
Edited by Sebastian Sinclair and Josh Quittner