Your brain could be older than you think

How old is your brain, really? 

Bryan Johnson, a 45-year-old entrepreneur best known for his obsession with reversing aging, recently strapped on a sleek neurotech headset called Kernel Flow. 

The device measured blood flow in his brain and ran the results through an algorithm that estimated his brain’s “biological age.” The verdict? Johnson’s brain is only 36. That nine-year gap, between chronological and biological age, isn’t just a curiosity.

The “brain age gap”

According to a new study in Neurology, this so-called “brain age gap” could help explain why some people maintain sharp memory and thinking skills well into old age, even in the face of risk factors like high blood pressure or diabetes, while others do not. 

“As we get older, our brains change, with less brain volume and fewer blood vessels that support brain tissue, and diseases can worsen these changes, profoundly affecting brain health,” says study author Dr Saima Hilal of the National University of Singapore. “Such signs of brain aging can be seen on brain scans, showing if a person’s brain looks older than their actual age.”

Hilal and her team analysed data from 1,437 adults with an average age of 66, none of whom had dementia. They examined participants’ medical histories, physical exams, lab tests and brain scans, using machine learning to estimate each person’s brain age from the scan data.

To assess cognitive performance, participants took tests for executive function, attention, language, memory, visuoconstruction, which involves the ability to copy a drawing or build a model, and visuomotor speed, which is how quickly it takes someone to process visual information and turn it into action.

Researchers found that higher cognitive impairment risk factor scores were consistently associated with poorer cognitive performance.

The team developed a brain age prediction model to review participants’ brain scans and determine the predicted biological brain age of each participant. They then subtracted a person’s chronological brain age from their predicted brain age to calculate their gap.

Interestingly, in people with signs of cerebrovascular disease — like tiny brain bleeds or mini-strokes — the brain age gap acted as a kind of biological middleman, mediating the relationship between risk factors and cognitive performance.

In simple terms, the more disease burden someone had, the more their brain aged beyond its years — and the more their thinking skills suffered. The brain age gap accounted for about 20% of the effect overall, and up to 34% for executive function and 27% for language skills.

“The brain age gap may be a helpful biomarker in determining a person’s risk of cognitive decline,” says Hilal. “Our findings suggest that accelerated brain aging may serve as an important factor linking cognitive impairment risk factors to thinking and memory skills in adults with cerebrovascular conditions.”

Please login to favourite this article.