- While the causes of dementia are complex, many cases of dementia can be linked to several modifiable risk factors.
- A new study finds that such risk factors are associated with nearly half of all dementias.
- One of the study’s key insights is that dementias are actually conditions that begin many years before symptoms appear, and that addressing risk factors early in life may allow one to avoid dementias later on.
- Vascular dementia, in particular, is linked to modifiable risk factors.
We can control, or at least positively influence, the risk factors associated with the development of nearly half of all dementias, says a new study from Skåne University Hospital in Sweden.
The study also reports that beta-amyloid plaques — a biomarker of Alzheimer’s disease — are tied to diabetes, while lower body mass index (BMI) was associated with accumulation of tau protein tangles, another Alzheimer’s biomarker.
The authors of the study analyzed data for 494 participants, with an average age of 65, who had enrolled in the prospective Swedish BioFINDER-2 study.
All were thoroughly evaluated during the process, with cerebrospinal fluid (CSF) analysis, PET imaging, MRI scans, and clinical and cognitive evaluations. They were tracked over 4 years as changes in their brains were observed and recorded.
As our understanding advances regarding the manner in which dementia progresses, it has become clear that its appearance is not simply a late-life matter.
Sarah Bullard, PhD, ABPP, Director of Psychology at Gaylord Specialty Healthcare, who was not involved in the recent study, remarked to Medical News Today:
“I just heard someone say the other day that dementia is a middle-age disease and not a disease of old age. The truth is that changes in your brain often begin decades before symptoms appear.”
This may be especially true of vascular dementia, which accounts for 17–30% of dementia cases.
The new study, said Dung Trinh, MD, “treats [white matter hyperintensity] progression as a moving marker, not just a static correlate of aging, and shows that specific risk factors lead to [white matter hyperintensity] accumulation in people at risk for Alzheimer’s disease.”
Trinh, who was also not involved in the study, is an internist at MemorialCare Medical Group in Irvine, CA.
According to him, the study “supports the model that dementia develops from interaction between non‑modifiable factors [such as] age, APOE [gene], and modifiable ones — hypertension, metabolic risk, cardiovascular health — acting through cerebral small‑vessel disease.”
“This strengthens the rationale that aggressive management of vascular/metabolic risk and educational/cognitive enrichment can slow the trajectory toward symptomatic dementia,” said Trinh.
“Early intervention is critical for better outcomes,” Bullard underscored. “Neurodegeneration isn’t an inevitable part of aging. It’s the result of a lifetime of choices and exposures.”
“This gives us a huge window of opportunity for intervention. But it also means that the choices we make today have consequences that extend far into the future,” she said.
“In contrast, [the study] shows how genetic risk factors, particularly carrying the APOE ε4 allele, are more closely associated with the accumulation of beta-amyloid and tau, the hallmark proteins of Alzheimer’s disease,” said Joel Salinas, MD, MBA, MSc, FAAN, Chief Medical Officer and Co-Founder of Isaac Health, who was also not involved in the study.
Nonetheless, even for Alzheimer’s disease, addressing the same risk factors can reduce the risk of developing the condition, according to the study.
“Evidence suggests,” said Salinas, “it’s never too early, thus never too late, to start” adopting habits associated with better brain health and dementia prevention.
“Longitudinal data suggest that dementia risk accumulates over decades, with early‑life education, midlife vascular/metabolic health, and late‑life sensory and social factors all contributing,” noted Trinh.
“Low education and early‑life cognitive enrichment appear to set a baseline for cognitive reserve, while midlife hypertension, obesity, and diabetes particularly drive vascular and neurodegenerative changes that emerge years later,” he pointed out.
“A practical interpretation would be to start in early adulthood (education, physical activity, avoiding smoking), be especially aggressive in midlife (roughly 40s–60s) on vascular and metabolic control, and then sustain lifestyle/sensory/social optimization into late life.“
– Dung Trinh, MD
“While genetic risk cannot be changed,” cautioned Salinas, “early and sustained lifestyle interventions can significantly reduce the likelihood or delay the onset of dementia later in life.”