Almost half of all dementia cases can be attributed to risk factors that we potentially can influence ourselves, such as smoking and high blood pressure. A new study from Lund University shows which risk factors are associated with two of our most common causes of dementia - Alzheimer's disease and vascular dementia.
During our lifetime, the risk of developing dementia is influenced by aspects that we cannot change, such as age, gender and genes. But there are also factors that we can change ourselves, such as smoking, cardiovascular disease, high blood lipids, physical activity, alcohol consumption, hearing loss and high blood pressure. Since dementia is not a single disease but a symptom of several underlying disorders, the risk profile also differs between different types of dementia. In the study from Lund University, researchers show how different risk factors affect changes in the brain linked to our two most common types of dementia - Alzheimer's disease and vascular dementia.
Different risk factors for different dementia mechanisms
"Much of the research available on the risk factors that we ourselves can influence does not take into account the different causes of dementia. This means that we have had limited knowledge of how individual risk factors affect the underlying disease mechanisms in the brain," explains Sebastian Palmqvist, senior lecturer in neurology at Lund University and senior physician at the Memory Clinic at Skåne University Hospital.
Long-term study of brain changes
The study included almost 500 people with an average age of 65, with preserved cognitive ability. Over a period of four years, changes in the brain's white matter - the nerve fibres that are often affected in vascular dementia - and levels of amyloid β and tau - the proteins linked to Alzheimer's disease - were measured. The aim of the study was to find out how risk factors, both those we can and cannot influence, are linked to changes in the brain over time.
Modifiable risk factors linked to vascular and Alzheimer's-related changes
"We saw that most modifiable risk factors - smoking, cardiovascular disease, high blood lipids and high blood pressure, among others - were linked to damage to the brain's blood vessels and a faster accumulation of so-called white matter changes. This damage impairs the function of the blood vessels and leads to vascular brain damage - and can ultimately lead to vascular dementia," says Isabelle Glans, doctoral student at Lund University and resident in neurology at Skåne University Hospital.
But the researchers also discovered risk factors linked to the Alzheimer's protein.
"Diabetes was associated with increased accumulation of amyloid β, while people with lower BMI had faster accumulation of tau. However, these findings need to be investigated further and validated in future studies", continues Isabelle Glans.
Living healthily and changing the risk factors that can be changed may help to delay the onset of symptoms in Alzheimer's disease. This is particularly important because many people with dementia actually have a combination of different underlying mechanisms, such as both vascular and Alzheimer's changes. Sebastian Palmqvist therefore emphasises the importance of a healthy lifestyle even in Alzheimer's disease:
"Focusing on vascular and metabolic risk factors can still help reduce the combined effects of several brain changes that occur simultaneously," he concludes.
Quick facts about the study: Clinical research // Peer-reviewed publication // Quantitative study // In vivo // Prospective // Longitudinal //
Publication
DOI: 10.1016/j.tjpad.2025.100448
Funding
National Institute of Health, Alzheimer's Association (USA), GHR, the Alzheimer Foundation, Hjärnfonden, Bundy Academy, the Swedish Research Council, MultiPark at Lund University
