Health & Medicine
How old are your internal organs?
Protecting your heart as you get older may also help protect your brain
New research finds that our heart and brain health are tightly linked, which may help explain why conditions like dementia and heart disease often happen together
Published 9 May 2025
Our heart and brain work together tirelessly throughout our lives. The brain regulates heart activity, while the heart supplies oxygenated blood to the brain.
Neither organ can function without the other.
As we age, brain and heart function decline. Eventually, this can lead to conditions like dementia and heart disease, as well as other degenerative health issues.
Unfortunately, heart diseases and neurodegenerative brain diseases, like dementia, often occur together.
This can make treatment difficult, putting a greater burden on the patients. But how do we explain heart and brain disease happening at the same time?
Our new research, published in the Journal of Neuroscience, shows that age-related changes in our cardiovascular system can selectively influence different brain networks.
Is the age of your brain and heart the same as the years you’ve lived?
While your age is typically measured by the number of years you’ve lived, the pace of aging can be different across our organs. The difference between an organ’s biological age and its chronological age can give us valuable insights into its health.
In our earlier research, we found that our organs can appear older or younger than our chronological age. For example, the lungs of a heavy smoker are likely to be significantly older than a non-smoker’s lungs of the same age.
Likewise, a 45-year-old could have a brain that appears more like that of a 55-year-old. But another 45-year-old could have a heart that appears more like a 35-year-old.
While many of the organs in our bodies age at different rates, our research suggests the biological aging of our heart and brain is tightly linked. We also think that this connected aging affects specific brain networks and heart features.
In our study, we analysed data of 3,000 healthy adults aged between 46 and 80 years from the UK (United Kingdom) Biobank, a large-scale anonymous biomedical database with health information on half a million UK adults.
Our team developed a model to calculate the biological age of a person’s brain and heart using MRI scans and ultrasound images, as well as physiological recordings of their heart activity.
Two organs, one aging trajectory
Our results show that if a person’s cardiovascular system appears older than their chronological age, it’s more likely that their brain will also be older– and vice versa.
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This may explain why brain and heart diseases often happen together. Importantly, it may give us an insight into how we can delay the onset of these diseases.
We also establish that cardiovascular aging is linked to age-related changes in specific brain networks: the somatomotor, default mode and salience networks, as well as key subcortical regions. Each of these networks plays a distinct role in everyday function.
The somatomotor network is responsible for processing our sensory information and coordinating movement.
For example, if you step on a sharp rock while walking barefoot, this network quickly detects the pain in your foot and signals your muscles to lift your foot away. It helps us respond to our environment by linking sensation and movement.
The default mode network, on the other hand, is active when we turn inward – whether daydreaming, recalling past experiences or imagining future events.
It’s the network that allows you to reflect on a childhood memory or plan your next vacation.
The salience network is crucial for processing pain, emotions, reward and motivation.
Our subcortical regions, located deep within the brain, are involved in a range of functions, including motor control, emotional processing and cognitive tasks.
Beyond their roles in thinking, sensing and movement, these brain networks are also involved in regulating our autonomic nervous system and heart function.
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This suggests that the connection between brain and heart aging isn’t just a coincidence – these systems are biologically linked.
Maintaining good cardiovascular and brain health
Our research highlights the importance of cardiovascular health in preserving brain structure and function.
A healthy lifestyle – including regular exercise, a balanced diet and stress management – not only supports heart function but may also help protect the brain, potentially reducing our risk of both heart disease and neurodegenerative conditions.
Understanding the link between brain and heart aging could lead to more effective, integrated approaches for predicting, preventing and managing these conditions.
For example, people showing early signs of cardiovascular aging could benefit from cognitive assessments, while those at risk for neurodegenerative diseases might undergo routine heart screenings.
By combining heart and brain assessments in practice and promoting a healthy lifestyle that supports both of these crucial organs, our research findings may help delay disease onset and inspire new approaches to improving our health and quality of life as we age.