Targeting the Right Brain: Structural Subtyping and Vascular Profiles Predict Response to Lifestyle Interventions in Dementia Prevention

Introduction

The global prevalence of dementia is projected to triple by 2050, presenting an unprecedented challenge to healthcare systems and public health infrastructure. While the recent FDA approvals of anti-amyloid monoclonal antibodies represent a milestone in Alzheimer’s disease (AD) therapeutics, these treatments are largely targeted at the early symptomatic stages and carry risks of amyloid-related imaging abnormalities (ARIA). Consequently, primary prevention remains the most viable strategy for reducing the global burden of cognitive decline. The landmark Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) randomized controlled trial (RCT) provided the first high-level evidence that a multidomain lifestyle intervention could improve or maintain cognitive function in at-risk older adults. However, a critical question remains: Why do some individuals show significant neural benefits from these interventions while others do not? A recent study by Lorenzon et al. (2025) published in the Journal of Prevention of Alzheimer’s Disease addresses this by investigating the role of brain structural heterogeneity and vascular risk profiles in modulating intervention response.

Highlights

The study identifies that baseline brain structural patterns, specifically grey matter (GM) distribution, significantly influence the efficacy of lifestyle interventions on brain preservation.
Individuals with diffuse or frontal-predominant cortical thinning, when paired with favorable vascular profiles (lower blood pressure and reduced obesity), showed the greatest reduction in cortical thinning following the FINGER intervention.
These findings suggest that ‘one-size-fits-all’ prevention strategies may be suboptimal and that neuroimaging-based subtyping could guide more personalized clinical recommendations.

Background: The Need for Precision Prevention

The FINGER trial demonstrated that a multidomain approach targeting diet, exercise, cognitive training, and vascular risk management can improve processing speed, executive function, and overall cognition. Despite these cognitive gains, longitudinal MRI studies across the entire FINGER cohort have often shown modest or inconsistent effects on brain structural markers like hippocampal volume or total grey matter volume. This discrepancy between cognitive improvement and structural change is likely due to the inherent heterogeneity of the aging brain. At-risk individuals do not possess a uniform neuroanatomical profile; some may exhibit early Alzheimer’s-like atrophy, while others show age-related frontal thinning or vascular-related changes. Understanding how these baseline brain ‘signatures’ interact with lifestyle changes is essential for transitioning from generalized advice to precision medicine in dementia prevention.

Study Design and Methodology

This observational sub-study of the FINGER RCT utilized a sophisticated unsupervised clustering approach to categorize 120 participants (61 intervention, 59 control) based on their baseline MRI data. Participants were aged 60 to 77 and were considered at risk for dementia based on a Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) score of 6 or higher, along with cognitive performance at or slightly below mean levels for their age.

The Multidomain Intervention

The intervention group underwent a intensive 2-year program consisting of:
1. Nutritional guidance based on Finnish Nutrition Recommendations (DASH-like diet).
2. Physical activity, including aerobic and resistance training.
3. Cognitive training using a web-based program.
4. Social engagement activities.
5. Intensive monitoring and management of metabolic and vascular risk factors.

Neuroimaging and Subtyping

The researchers employed unsupervised clustering of cortical thickness and subcortical volume metrics. This allowed them to define subgroups (clusters) with distinct patterns of grey matter distribution. Furthermore, they utilized specific ‘cortical signatures’ associated with Alzheimer’s disease and ‘resilience’ (areas known to be preserved in cognitively healthy aging). The primary outcomes were the longitudinal changes in mean cortical thickness, the AD-signature regions, the resilience-signature regions, and hippocampal volume, analyzed via hierarchical linear models.

Key Findings: Who Benefits Most?

The study’s results provide a nuanced view of how the brain responds to lifestyle modification. The researchers identified specific clusters characterized by diffuse cortical thinning or frontal-predominant thinning. Interestingly, the response to the intervention was not uniform across all clusters.

The Synergy of Brain Structure and Vascular Health

The most significant finding was that participants within clusters exhibiting cortical thinning but who also maintained more favorable vascular profiles—specifically lower systolic blood pressure and lower body mass index (BMI)—showed significant structural benefits from the intervention. In these individuals, the FINGER intervention was associated with significantly less thinning in:
– Mean global cortical thickness (p < 0.05)
– AD-signature regions (p < 0.05)
– Resilience-signature regions (p < 0.05)

Conversely, individuals with high vascular risk at baseline or those with more advanced, localized atrophy patterns did not show the same degree of structural preservation. This suggests that the 'window of opportunity' for structural brain maintenance via lifestyle intervention may be widest in those who have not yet reached a threshold of significant vascular damage.

Cognitive vs. Structural Divergence

While the intervention improved cognitive performance across various domains (executive function, processing speed), the structural benefits were more localized to specific subgroups. This highlights the concept of ‘brain maintenance’—the idea that lifestyle interventions may slow the rate of biological aging in the brain, provided the baseline vascular environment is conducive to such preservation.

Expert Commentary and Mechanistic Insights

The findings by Lorenzon et al. underscore the biological plausibility of the FINGER intervention. The mechanisms are likely multifactorial: physical activity increases brain-derived neurotrophic factor (BDNF), the DASH diet reduces systemic inflammation and oxidative stress, and vascular management preserves microvascular integrity. However, if the neurodegenerative process or vascular damage is too advanced, the brain’s capacity for plastic reorganization or ‘maintenance’ may be compromised.

From a clinical perspective, these results suggest that we should be assessing ‘brain health’ more holistically. A patient with early frontal thinning but well-controlled blood pressure might be the ideal candidate for an aggressive multidomain lifestyle program. On the other hand, for those with high vascular burden, the priority must remain the aggressive management of hypertension and metabolic syndrome before the full neuroprotective benefits of exercise or diet can be realized.

Study Limitations

It is important to note the relatively small sample size of this sub-study (n=120), which may limit the generalizability of the specific clusters identified. Additionally, the 2-year duration of the RCT, while substantial, may still be too short to see dramatic changes in hippocampal volume, which often requires longer follow-up in non-demented populations. Future research should aim to replicate these clusters in larger, more diverse cohorts like the World-Wide FINGERS network.

Conclusion

The FINGER trial has already revolutionized our approach to dementia prevention, proving that lifestyle matters. This recent analysis adds a critical layer of depth: the brain’s baseline structure and the body’s vascular health are major determinants of how much benefit an individual will derive. By stratifying at-risk populations using MRI-based subtyping and vascular risk profiles, clinicians can better predict intervention outcomes and move closer to personalized, evidence-based strategies for cognitive longevity.

Funding and Trial Registration

The FINGER study was supported by various grants, including the Academy of Finland, the La Carita Foundation, and the Alzheimer’s Research & Prevention Foundation. ClinicalTrials.gov Identifier: NCT01041989.

References

1. Lorenzon G, Marseglia A, Mohanty R, et al. Brain patterns and risk factors in the FINGER RCT multimodal lifestyle intervention. J Prev Alzheimers Dis. 2025;12(10):100390.
2. Ngandu T, Lehtisalo J, Solomon A, et al. A 2 year multidomain intervention of diet, exercise, cognitive training, and vascular risk monitoring versus control to prevent cognitive decline in at-risk elderly people (FINGER): a randomised controlled trial. Lancet. 2015;385(9984):2255-2263.
3. Kivipelto M, Mangialasche F, Ngandu T. Lifestyle interventions to prevent cognitive impairment, dementia and Alzheimer disease. Nat Rev Neurol. 2018;14(11):653-666.