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In a nutshell
- Even mild heart problems can affect brain structure, particularly in memory-related regions like the hippocampus, years before cognitive symptoms appear
- Heart dysfunction impacts brain volume from middle age onward, with women showing greater brain volume reduction than men with comparable heart issues
- Heart-healthy lifestyle choices (regular exercise, balanced diet, stress management) may help preserve brain health and potentially reduce risk of cognitive decline
ROTTERDAM, Netherlands — Your heart and brain may seem like separate biological systems, but emerging research reveals they’re more intimately connected than previously realized. A new study uncovers compelling evidence that even subtle heart issues may affect brain structure — potentially years before any cognitive symptoms emerge.
Doctors have long noticed that heart failure patients often struggle with memory and thinking skills, but the underlying reasons remained mysterious. This extensive analysis by an international team of scientists offers new insights, suggesting that keeping your heart healthy might be crucial for maintaining brain function as you age.
Published in Neurology, the study examined data from nearly 11,000 adults across Europe and the United States. Researchers investigated connections between heart function (measured by heart imaging) and brain structure (visible on brain MRI scans). What they discovered was surprising: even subtle heart issues that haven’t caused obvious symptoms correlate with measurable changes in brain volume, especially in regions essential for memory.
The research team was led by Dr. Frank J. Wolters from Erasmus MC in Rotterdam, Netherlands, alongside Dr. Sudha Seshadri from the University of Texas Health Science Center. Their findings could significantly impact preventative healthcare. While the observed brain volume differences were relatively modest, they represent changes that build up over decades and may influence cognitive resilience later in life.
Why Does The Heart Affect Brain Volume?
Your heart’s main job is pumping oxygen-rich blood throughout your body. Though your brain makes up just 2% of your body weight, it’s extraordinarily demanding — requiring roughly 20% of your body’s oxygen supply. When your heart struggles to pump efficiently, your brain may be among the first organs to show the effects.
Researchers examined several heart measurements, including fractional shortening (how well the heart’s left ventricle contracts), left ventricular ejection fraction (percentage of blood pumped out with each heartbeat), and diastolic function indicators like the EA-ratio (measuring blood flow patterns during the heart’s filling phase).
Participants with moderate to severe systolic dysfunction (problems with the heart’s pumping phase) showed noticeably smaller brain volumes compared to those with normal heart function. Similarly, diastolic dysfunction (difficulties with the heart’s filling phase) correlated with reduced brain size, particularly affecting the hippocampus — a curved brain structure crucial for forming memories.
When comparing these heart measurements with brain MRI scans, clear patterns emerged. People with clinical heart failure showed approximately 13% smaller hippocampal volume than those without heart failure. Even among participants without diagnosed heart problems, those with subtle cardiac dysfunction showed measurable differences in brain structure.
These patterns persisted even after researchers accounted for numerous factors that affect both heart and brain health, including blood pressure, diabetes, smoking history, and genetics. This suggests a direct relationship between heart efficiency and brain structure independent of these common risk factors.
Who Is Most At Risk?
The connection between heart function and brain volume was particularly pronounced in the hippocampus for individuals with restrictive diastolic dysfunction — characterized by stiffened heart muscles that hinder proper filling of the heart’s chambers. This pattern helps explain why memory problems often emerge early in heart failure patients.j
Perhaps most striking, these brain changes appeared in otherwise healthy adults without diagnosed heart disease. This indicates that minor cardiac inefficiencies may affect brain health long before heart problems become obvious. These effects were observable from middle age onward, highlighting the importance of heart health throughout adulthood.
Another interesting finding involved the relationship between diastolic dysfunction and white matter hyperintensities — bright spots on brain MRIs indicating small blood vessel damage. Higher deceleration time, which signals impaired heart relaxation, corresponded with greater volume of these hyperintensities, suggesting a possible connection between heart dysfunction and cerebral small vessel disease.
The links between heart function and brain volumes were most evident from middle-age onward, but appeared less pronounced in participants over 70. This could reflect age-related changes in brain structure that eventually overshadow the specific impact of heart function, or might result from survivor bias, as those with the most severe heart dysfunction may not live to advanced age.
The study also found potential sex differences in how heart dysfunction affects the brain. Women with systolic dysfunction showed smaller total brain volumes compared to men, particularly in white matter and hippocampal regions. This matches growing evidence that heart disease manifests differently in women than men, with potentially different implications for brain health.
While this study’s cross-sectional design means it can’t definitively prove that heart dysfunction causes brain shrinkage (rather than both resulting from some other common factor), the relationships observed align with known physiological mechanisms. Reduced cardiac output could lead to chronic brain hypoperfusion (decreased blood flow), which might gradually contribute to neuronal damage and loss.
Take Care Of Your Heart To Protect Your Mind
These findings build on previous research suggesting that cardiac output (blood pumped by the heart per minute) and other heart function measures correlate with brain volume. However, this new study offers greater precision in understanding how specific aspects of heart function relate to various brain structures, addressing limitations of earlier investigations.
For everyday people, these findings add to the importance of heart health throughout life — not just to prevent heart attacks and strokes, but also to protect thinking abilities. Simple heart-healthy practices like regular physical activity, balanced nutrition rich in fruits and vegetables, avoiding tobacco, limiting alcohol, and managing stress may boost brain health through their beneficial effects on heart function.
Healthcare providers might also consider cognitive assessment for patients with heart dysfunction, even when it’s mild or subclinical. Conversely, people showing early signs of cognitive decline might benefit from thorough heart evaluation to identify potentially modifiable heart issues that could contribute to their symptoms.
The heart and brain, once viewed as separate systems, increasingly appear engaged in constant communication, with one directly influencing the health of the other. Preserving this vital conversation may be key to healthy aging of both organs, showing that in human physiology, no system truly operates independently.
Points of Contention
Like any study, there are limitations and areas of concern when it comes to evaluating the findings. Here’s what readers should keep in mind:
Cross-sectional design: The study captures a single point in time rather than tracking changes over years. This means it shows correlation but cannot definitively prove that heart problems cause brain changes.
Technical limitations: Researchers couldn’t use the most advanced heart imaging techniques (tissue Doppler imaging) because this data wasn’t consistently available across all study populations.
Participant demographics: While some cohorts included diverse populations, most participants were of European ancestry, potentially limiting how these findings apply to other ethnic groups.
Few severe cases: The study included relatively few participants with advanced heart dysfunction, which may have limited the ability to detect patterns in those with the most serious conditions.
Funding considerations: While no direct funding was reported specifically for this meta-analysis, the seven individual cohort studies receive support from various sources, including government agencies and academic institutions. No conflicts of interest were disclosed, but readers should consider that large-scale research often involves complex funding relationships.
Alternative explanations: Despite controlling for many factors, unmeasured variables might still influence both heart and brain health simultaneously, creating the appearance of a direct relationship.
Paper Summary
Methodology
This study combined information from seven long-term health studies conducted across Europe and the United States. Nearly 11,000 participants had both heart tests and brain MRI scans. The average participant age was about 67 years, and just over half were women. Each study measured heart function using standard techniques to assess how well the heart pumps blood and how effectively it relaxes and fills between beats. Brain measurements from MRI scans determined the volume of different brain regions, including the total brain, gray matter, white matter, hippocampus, and white matter hyperintensities (bright spots indicating small vessel damage). For consistent analysis, each study performed identical statistical tests, accounting for factors like age, sex, smoking, body mass index, blood pressure, cholesterol levels, diabetes, and heart disease history. Results were combined using random-effects meta-analysis, a statistical technique that accounts for differences between studies while finding consistent patterns across them.
Results
The findings revealed several important connections between heart function and brain structure. People with moderate to severe systolic dysfunction (poor pumping ability) had smaller total brain volumes compared to those with normal heart function. The adjusted standardized mean difference was -0.19, meaning their brain volumes were about 0.19 standard deviations smaller on average. Similar patterns appeared for both gray and white matter volumes. For diastolic dysfunction (poor filling ability), participants with impaired relaxation had smaller total brain volumes (difference of -0.08) compared to those with normal diastolic function. Those with restrictive diastolic dysfunction had notably smaller hippocampal volumes (difference of -0.18), suggesting this memory-critical brain region may be especially vulnerable to certain types of heart problems. Among participants with clinical heart failure (about 3.4% of the sample), brain volumes were consistently smaller, with the hippocampus showing the strongest connection (difference of -0.13). Higher deceleration time (indicating worse diastolic function) corresponded with more white matter hyperintensities, suggesting a link between heart problems and small vessel disease in the brain. These connections appeared across all age groups from 40 years onward, though they seemed less pronounced in participants over 70. Sex-specific analyses indicated that women with systolic dysfunction had smaller brain volumes than men with comparable heart problems.
Limitations
While comprehensive, this research has several limitations. Its cross-sectional design shows associations at just one point in time rather than tracking changes over years, making it impossible to definitively establish whether heart dysfunction causes brain atrophy or whether both might stem from another common factor. The researchers couldn’t use tissue Doppler imaging (a more advanced technique for assessing diastolic function) because this data wasn’t available across all cohorts. Few participants had advanced stages of cardiac dysfunction, potentially limiting the ability to detect associations in those with severe heart problems. Despite efforts to standardize MRI data processing across cohorts, differences in imaging protocols and scanner settings could have affected the comparability of brain measurements. While the study adjusted for many potential confounding factors, unmeasured variables might still influence the observed relationships. Finally, although some cohorts included ethnically diverse populations, most participants were of European ancestry, potentially limiting how widely these findings apply to other ethnic groups.
Funding and Disclosures
The researchers reported no direct funding specifically for this meta-analysis. However, each of the seven cohort studies included receives funding from various sources, including national research institutes, government agencies, and academic institutions. These funding details appear in the supplementary materials of the published paper. The authors disclosed no relevant conflicts of interest that might influence their interpretation or reporting of the study findings.
Publication Information
This research appeared in Neurology (Volume 104, Number 8) on April 22, 2025, titled “Clinical and Imaging Markers of Cardiac Function and Brain Health: A Meta-Analysis of Community-Based Studies.” The lead authors were Amber Yaqub, Joshua C. Bis, Stefan Frenzel, and others, with Frank J. Wolters and Sudha Seshadri as senior authors representing the Cross-Cohort Collaboration. The article can be found with the digital object identifier (DOI): 10.1212/WNL.0000000000213421. The publication is open access, freely available to read without a subscription or payment.
