Healthier diet linked to lower dementia in older adults at risk
A healthier diet may be associated with a lower risk of dementia among older adults, including those with blood biomarkers indicating increased biological risk, including of Alzheimer's disease pathology. This is shown in a new study from Karolinska Institutet published in JAMA Network Open.
Dementia develops over many years, often long before symptoms appear. New blood-based biomarkers can detect biological changes linked to Alzheimer’s disease and other neurodegenerative processes at an early stage. However, it remained unclear whether lifestyle factors, such as diet, are still associated with dementia risk once such biological changes are already detectable.
Researchers from Karolinska Institutet, led by Davide Liborio Vetrano, Associate Professor in Geriatric Research at the Aging Research Center (ARC), Department of Neurobiology, Care Sciences and Society (NVS), analysed 1,865 adults aged 60 years and older, free from dementia, and followed them up to 15 years. The participants were part of the Swedish National Study on Aging and Care in Kungsholmen. Their dietary habits were assessed repeatedly, and risk of dementia was analysed in relation to blood biomarkers associated with Alzheimer’s disease pathology, neuronal damage, and inflammation-related glial processes.
It was found that higher adherence to healthier dietary patterns was associated with a lower risk of dementia. Notably, this association was also observed among individuals with elevated blood biomarker levels, indicating increased biological risk.
Diets with lower inflammatory potential stood out
The study examined three dietary patterns: the Alternative Mediterranean Diet, the Alternative Healthy Eating Index and a reversed Empirical Dietary Inflammatory Index. This allowed a comparison of dietary patterns related to Mediterranean diet, cardiovascular health, and systemic inflammation, respectively, and to explore whether some dietary patterns may be especially relevant for people at higher biological risk.
The most consistent findings were observed for dietary patterns with lower inflammatory potential. Among participants with elevated levels of Alzheimer’s disease-related and neurobiological risk biomarkers, greater adherence to such a diet was associated with a lower risk of dementia. For example, among these participants, a diet with lower inflammatory potential was linked to up to a 30% lower relative risk of developing dementia.
"Our findings suggest that diet quality, and particularly dietary patterns with inflammatory potential, may be relevant for dementia prevention in people who already show biological signs of increased risk," says corresponding author Anja Mrhar, PhD student from University of Ljubljana, Slovenia, and affiliated at ARC.
The findings connect two rapidly developing areas in dementia research: early identification of biological risk through blood-based biomarkers and prevention through modifiable lifestyle factors.
Relevance for dementia prevention
Blood-based biomarkers are increasingly used in research to identify people at higher risk of developing dementia. At the same time, prevention has become an important focus in the clinic, as well as public health. The results suggest that diet may be one factor that could influence how dementia develops over time, even after early biological changes have begun.
"These findings move us closer to precision nutrition, suggesting that different dietary patterns may be particularly beneficial for different groups of older adults," states Adrián Carballo-Casla, postdoctoral researcher at ARC and co-leading author of the study.
However, the researchers emphasise that this study is observational and cannot prove that diet prevents dementia, but it suggests that lifestyle may still influence how the disease develops, even when early warning signs are present.
Further studies are needed to confirm the results in other populations and to identify which specific foods or nutrients may be most important.
Publication
Diet Quality and Dementia Risk in Older Adults With Alzheimer Pathology
Anja Mhrar*, Adrián Carballo- Casla*, Giulia Grande, Caterina Gregorio, Federico Triolo, Martina Valletta, Claudia Fredolini, Milica Gregorič Kramberger, Aleš Kuhar, Bengt Winblad, Laura Fratiglioni, Amaia Calderón-Larrañaga, Davide Liborio Vetrano, JAMA Network Open, 25 June 2026, doi: 10.1001/jamanetworkopen.2026.20254
* co-first authors