Smoking, high blood pressure, high blood lipids and cardiovascular disease tracked with damage to the brain's blood vessels and faster accumulation of white matter changes over four years, while relating less consistently to the amyloid and tau proteins associated with Alzheimer's disease.
The finding comes from a Lund University study of nearly 500 people with an average age of 65 and preserved cognitive ability, published in The Journal of Prevention of Alzheimer's Disease. Data came from the Swedish BioFINDER-2 cohort, collected between May 2017 and January 2025.
"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," said Isabelle Glans, a doctoral student at Lund University and a neurology resident at Skåne University Hospital. "This damage impairs the function of the blood vessels and leads to vascular brain damage, and can ultimately lead to vascular dementia."
The Signal the Imaging Actually Captured
White matter is the tissue containing the nerve fibers that connect brain regions, and it depends on a dense network of small blood vessels.
On MRI, damage to that tissue appears as white matter hyperintensities, bright patches indicating areas where the tissue has been injured, typically by inadequate blood supply from diseased small vessels. These accumulate with age in most people, and the rate of accumulation is what distinguishes normal aging from a disease process.
Longitudinal imaging is what makes this study informative. A single scan shows how much damage exists, which conflates a lifetime of accumulation with current disease activity. Repeated scans over four years show how fast damage is being added, and the researchers could then ask which risk factors predicted a faster rate.
Two exceptions to the vascular pattern matter and are easy to miss. Diabetes was associated with accelerated amyloid accumulation, and lower body mass index with faster tau accumulation. The authors cautioned that both findings need further validation. Their overall conclusion is that modifiable risk factors of future dementia primarily affect accumulation of cerebral vascular pathology, with those two exceptions noted.
The Mechanisms That Separate the Two Diseases
Alzheimer's disease and vascular dementia produce overlapping symptoms through different biology, and the difference determines what can be changed.
Alzheimer's involves accumulation of amyloid plaques outside neurons and tau tangles inside them, followed by neuron loss concentrated initially in memory regions. Its strongest risk factors are age and genetics, including the APOE ε4 variant, neither of which anyone can modify.
Vascular dementia results from damage to the blood supply itself, through small vessel disease, strokes or a series of small infarcts. Its risk factors are the risk factors for vascular disease anywhere in the body: blood pressure, lipids, smoking, diabetes and existing cardiovascular disease.
The presentations differ accordingly. Alzheimer's typically begins with memory difficulty and progresses gradually. Vascular dementia more often begins with slowed thinking, difficulty with planning and executive function, and can progress in a stepwise pattern when discrete vascular events occur.
Mixed pathology is common in practice, and the two interact. Senior author Sebastian Palmqvist, a neurology researcher at Lund, said improving vascular and metabolic health may therefore remain valuable even for people at risk of Alzheimer's disease, because it can reduce the combined effects of several brain changes occurring simultaneously.
The Limits and What the Design Cannot Show
This is observational research. It identifies which risk factors track with which imaging changes; it does not demonstrate that treating them prevents dementia.
The cohort was cognitively preserved at baseline with an average age of 65, and four years is short relative to the decades over which dementia develops. Whether faster white matter accumulation in this group translates into more clinical dementia later is a question this design cannot answer.
Palmqvist noted that prior research often failed to account for the distinct underlying pathologies of dementia, which meant limited knowledge of how individual risk factors affect disease mechanisms in the brain. That is the gap this study addresses, and filling it is a different achievement from demonstrating that intervention works.
The evidence that controlling vascular risk factors reduces dementia risk comes from separate work, and it is reasonably strong, though not definitive. MedicalDaily has covered prescribing questions for older adults managing several of these conditions at once. The study was funded by public and nonprofit sources including the National Institute on Aging, the Alzheimer's Association, the European Research Council and Swedish research bodies.
The Practical Reading for Readers
Approximately 45% of dementia cases are estimated to be attributable to potentially modifiable risk factors, which is the framing that makes this research worth acting on rather than worrying about.
The concrete items are the ones a primary care visit already covers. Knowing a blood pressure number rather than assuming it is fine, since hypertension is asymptomatic. Having lipids checked. Stopping smoking, which is the single modifiable factor with the broadest effect across both vascular and general health. Managing diabetes, which in this study was also the factor linked to amyloid accumulation.
None of this is novel advice, and that is the point. What this line of research adds is a mechanism: these factors are not vaguely bad for the brain; they damage the small vessels supplying white matter, and that damage is visible and measurable on imaging years before symptoms appear.
Anyone noticing changes in memory, planning or word finding should be evaluated rather than waiting, since some causes of cognitive symptoms are treatable and reversible, including thyroid disease, vitamin deficiency, medication effects, depression and sleep apnea. MedicalDaily has covered research complicating the tau-focused approach to Alzheimer's drug development and the metabolic medications now reshaping several of these risk factors.
Key Questions Answered
What did the study find? Over four years in nearly 500 cognitively preserved adults averaging age 65, smoking, cardiovascular disease, high blood lipids and high blood pressure tracked mainly with blood vessel damage and faster accumulation of white matter changes. Diabetes was linked to amyloid accumulation and lower body mass index to tau accumulation.
What are white matter hyperintensities? Bright patches on MRI indicating injured white matter, typically from inadequate blood supply through diseased small vessels. They accumulate with age, and the rate of accumulation distinguishes normal aging from disease.
How does vascular dementia differ from Alzheimer's? Alzheimer's involves amyloid plaques and tau tangles, with age and genetics as leading risk factors. Vascular dementia results from damaged blood supply, with risk factors that are the same as for vascular disease elsewhere.
Do the symptoms differ? Alzheimer's typically begins with memory difficulty and progresses gradually. Vascular dementia more often begins with slowed thinking and difficulty with planning, and can progress in steps when discrete vascular events occur.
Does this prove treating risk factors prevents dementia? No. This is observational research identifying which risk factors track with which imaging changes over four years. Evidence that controlling vascular risk reduces dementia risk comes from separate work.
How much of dementia is potentially modifiable? Approximately 45% of cases are estimated to be attributable to potentially modifiable risk factors.
When should memory changes be evaluated? Promptly. Some causes of cognitive symptoms are treatable and reversible, including thyroid disease, vitamin deficiency, medication effects, depression, and sleep apnea.
