A recent study links weight gain to dementia.
A recent study concluded that being overweight and obese are not only factors associated with vascular dementia, but may also play a direct role in increasing its risk, particularly through their effect on blood pressure and blood vessels in the brain.
How does the study link weight and dementia?
The study was conducted at the University of Copenhagen in Denmark, where researchers used Mendelian randomization—a technique that mimics clinical trials—to study the relationship between obesity (body mass index) and the risk of vascular dementia.
The results – published by Medical News Today – showed that an increase in body mass index enhances the risk of vascular dementia, partly through high blood pressure and its effect on blood vessels in the brain.
What does vascular dementia mean?
Vascular dementia is the second most common form of dementia after Alzheimer’s. It occurs when blood vessels in the brain are damaged or blocked, reducing blood and oxygen flow to nerve tissues, which affects memory, thinking, and behavior.
Obesity and high blood pressure
The team explained that high blood pressure is an important mediator in the relationship between obesity and vascular dementia:
- Systolic blood pressure contributes about 18% of the total effect.
- Diastolic blood pressure contributes about 25%.
This suggests that high blood pressure resulting from obesity damages the blood vessels of the brain, predisposing individuals to vascular dementia later on.
Why is this discovery important?
“Our results show that obesity and high blood pressure are direct risk factors for vascular dementia, making them modifiable targets for community-level prevention,” says Dr. Ruth Frick-Schmidt, lead author of the study and a clinical physician at the University of Copenhagen.
Another physician involved in the evaluation explained that the use of genetic analysis reduced the biases that had limited previous studies, making the results closer to causal evidence.
Obesity and brain health
One of the key conclusions is that controlling weight and blood pressure, especially in middle age, may constitute a practical preventive strategy to reduce the risk of vascular dementia later in life.
According to experts not involved in the study, these findings support the idea that vascular health is linked to brain health, and that early intervention to modify risk factors such as high weight can reduce the future burden of dementia.
Who does this research apply to?
Despite the strength of the findings, the researchers point out that the study only included people of European descent, which may limit the generalizability of the results to the entire global population.
There are also challenges in accurately identifying the types of dementia in the databases used, issues that require further studies to confirm the results.
