Almost half of all dementia cases are tied to habits we can change, such as smoking or high blood pressure. A new study from Lund University explains how these habits affect the two most common forms of dementia: Alzheimer’s disease and vascular dementia.
Some risk factors cannot be altered – age, sex, and genetics are fixed. Other factors are within our control, including smoking, heart disease, high cholesterol, lack of exercise, alcohol use, hearing loss, and high blood pressure.
Dementia is not a single illness. It is a group of symptoms that can come from many different brain problems. Because of this, the risk factors may act differently for each type. The Lund researchers looked at how each factor relates to brain changes seen in Alzheimer’s and vascular dementia.
"Most studies ignore the fact that dementia has many causes," said Sebastian Palmqvist, a senior lecturer in neurology. "We needed to see how each lifestyle factor impacts the brain itself."
Four‑Year Brain Monitoring
The team followed nearly 500 people, average age 65, who showed no memory problems at the start. Over four years they measured the brain’s white‑matter pathways, which often get damaged in vascular dementia.
They also tracked two proteins—amyloid‑β and tau—that are linked to Alzheimer’s. This allowed them to see how both changeable and unchangeable risks affect the brain over time.
Vascular Risks Hurt Brain Blood Vessels
Most of the modifiable risks—smoking, heart disease, high cholesterol and high blood pressure—were tied to damage in the brain’s tiny blood vessels. That damage sped up the loss of white‑matter health.
"When the vessels are injured, the brain cannot get enough blood, which leads to vascular dementia," explained Isabelle Glans, a doctoral student.
The study also found clues about Alzheimer’s proteins. Diabetes was linked to more amyloid‑β buildup, while people with a lower body‑mass index showed faster tau accumulation. These findings need more research.
Healthy Habits May Slow Multiple Brain Changes
Adopting better habits—like quitting smoking, controlling blood pressure, and staying active—could delay the start of Alzheimer’s symptoms. Many people with dementia have both vascular damage and Alzheimer‑type changes, so improving overall vascular and metabolic health may help protect the brain.
"Even if you are at risk for Alzheimer’s, caring for your heart and metabolism can reduce the combined damage in the brain," Palmqvist concluded.