Cardiovascular health in early life linked to brain structure changes

Poorer cardiovascular health in childhood and adolescence may be linked to early differences in brain structure, particularly in areas of the brain known to be affected in dementia in later life, according to a new scientific study.

Obesity, hypertension (high blood pressure) and physical inactivity are known to be cardiovascular risk factors for dementia in middle age but, so far, little is known about these links between heart and brain health much earlier in life.

Researchers led by a team at the University of Oxford’s Department of Psychiatry, in collaboration with University College London, looked at data from more than 860 children and young people between the ages of 7 and 17, including brain scans, levels of physical activity, blood pressure and body mass index (BMI).

The new paper, published in the journal eBioMedicine, found a link between increased BMI, higher blood pressure, and lower physical activity in adolescence and subsequent brain structure in young adulthood—a period when the body undergoes significant change.

The links were particularly evident in brain regions that are known to be affected in dementia in old age, suggesting that lifestyle changes early in childhood may set the stage for later decline in brain health.

Holly Haines, lead author on the paper, said, “Our research shows that cardiovascular health in the earliest stages of life may already be important for the structure of brain regions known to be affected in dementia in old age—much earlier than previously thought.”

The scientists found that markers of poorer cardiovascular health (such as higher childhood blood pressure and faster growth of BMI across adolescence) were associated with differences in the structure of a type of brain tissue called gray matter—including its thickness and surface area. These findings were predominantly in brain areas which are known to be involved in thinking and memory. Similar links between heart health and brain health have already been shown in older patients with memory difficulties and dementia.

They say the research could help pave the way in identifying and mitigating dementia risks earlier in life, but that further research is needed with a more diverse group of participants to be able to generalize the findings to the wider population.

Co-author of the paper, Associate Professor Sana Suri from the Department of Psychiatry at the University of Oxford, added, “The findings suggest that we should be thinking about targeting modifiable lifestyle risk factors, such as obesity and exercise, decades before current lifespan models of dementia suggest. The early adolescent years merit greater consideration in the context of dementia prevention.”

Data for the study was obtained from the Avon Longitudinal Study of Parents and Children (ALSPAC), a world-leading birth cohort study based at the University of Bristol.

David Thomas, Head of Policy and Public Affairs at Alzheimer’s Research UK, said, “This study suggests that not looking after our hearts even in adolescence could lead to changes in the brain later on in life, which may influence the risk of developing dementia.

“Up to 45% of dementia cases can be prevented by avoiding risk factors that we can influence, such as physical inactivity and smoking. These are habits that some people pick up in early life, without knowing the potential long-term consequences for their brain health.

“Dementia is not just an inevitable part of aging. By supporting research like this study, we are gaining insights into how people might be able to prevent dementia happening in the first place, which is vital if we want to reach a cure for this devastating condition.”