Readers can now see a clearer picture of who is most vulnerable to dementia later in life: a new analysis of the Framingham Offspring Study, published in Scientific Reports, found that women whose biological age ran ahead of their chronological age in midlife faced a significantly higher risk of dementia over a median 26 years of follow-up. The same link did not appear in men, even though both sexes showed higher cardiovascular and mortality risk from accelerated aging.
What the study measured
Biological age reflects how well a person’s cells and systems are functioning, and it can move faster or slower than the number of birthdays they have had. The research team estimated biological age from clinical biomarkers including total blood cholesterol, blood sugar, and scores on the Mini-Mental State Exam, a standard cognitive screening tool. Participants were grouped as accelerated, decelerated, or concordant, meaning their biological age roughly matched their calendar age.
More than 3,000 participants were tracked for a median of 26 years. Among those whose biological age exceeded their chronological age, men were on average 4 years older biologically than their years on paper, while women were 2.5 years older. The researchers also adjusted for diabetes, blood pressure medication use, and smoking status.
What the long-term data showed
During follow-up, the study recorded 713 cardiovascular disease events, 1,105 deaths, and 265 dementia cases. The pattern that emerged was sex-specific for the brain:
- Women with accelerated biological age had a statistically significant increase in dementia risk, and sensitivity analyses confirmed that women with accelerated or even concordant biological age were at higher risk compared with those whose aging had slowed.
- Men showed no significant rise in dementia risk from accelerated biological age.
- Both men and women with accelerated aging had roughly double the mortality risk.
- Accelerated biological age was tied to a 1.6-fold higher cardiovascular risk in men and a 1.8-fold higher risk in women, compared with peers whose biological age had decelerated.
Why the sex difference matters
Nearly two-thirds of Alzheimer’s disease patients are women, a disparity that researchers have long sought to explain, according to a separate study in Alzheimer’s Research and Therapy. The new findings add a possible clue: the gap may partly reflect how fast women’s cells are aging in midlife, not just how long they live. Future studies will need to examine the drivers behind that difference, including hormones, immune function, and environmental exposures.
What experts say about using biological age in practice
The authors were clear that the design is observational and cannot prove cause and effect. Biological age also remains a proxy measure with no standardized calculation method, which limits how it can be used. Adding biological age to existing risk models improved prediction only marginally: the change in the c-statistic, a measure of how well a model distinguishes between people who do and do not develop a condition, ran from essentially zero to about 0.01. The measure tracks risk, but it does not add much beyond what individual risk factors already reveal.
Standardized clinical definitions are needed before biological age becomes a routine tool. There is no therapy for accelerated aging itself, so the path forward is to treat the underlying components, including blood pressure, blood sugar, smoking, diet, sleep quality, and stress. Those are the same factors that large-scale studies have tied to dementia-free years later in life: avoiding high blood pressure, diabetes, and smoking in midlife has been linked to about 13 additional dementia-free years.
Modifiable factors worth attention
The study points to lifestyle factors that can be addressed now, before biological age measures are widely used in clinics.
- Blood pressure control: one of the strongest midlife predictors of later dementia.
- Blood sugar management: tied to both cardiovascular and cognitive outcomes.
- Smoking cessation: a persistent driver of accelerated aging and mortality.
- Dietary fiber intake: linked in other research to lower dementia risk and better mood regulation.
- Moderate exercise in midlife: tied to better brain health decades later.
- Sleep quality, stress, and environmental chemical exposure: candidate drivers that future research is working to clarify.
FAQ
What did the Framingham Offspring Study find about biological age and dementia?
Tracking more than 3,000 adults for a median of 26 years, the study published in Scientific Reports found that women whose biological age exceeded their chronological age in midlife had a significantly higher risk of dementia. Men with accelerated biological age did not show the same increase in dementia risk, although both sexes had higher cardiovascular and mortality risk.
How is biological age different from chronological age?
Chronological age is the number of years a person has been alive. Biological age estimates how well their cells and systems are functioning based on biomarkers like cholesterol, blood sugar, and cognitive test scores. A person can be biologically older or younger than their calendar age suggests.
Can biological age be used to predict dementia risk today?
Not yet as a routine clinical tool. The study authors and outside experts noted that biological age is a proxy measure with no standardized calculation, and that adding it to existing risk models improved prediction only marginally. Treating individual risk factors such as blood pressure, blood sugar, smoking, and diet remains the recommended approach.
