Plant-Based Dietary Patterns and Neuroimaging Biomarkers of Brain Health: A Scoping Review of Observational and Interventional Evidence.

Healthy dietary interventions are well established in cardiovascular disease prevention, but their effects on the brain remain underexplored. This scoping review aims to investigate how adherence to core components of a whole-food plant-based diet (WFPBD) may impact neuroimaging outcomes across different brain conditions. We searched PubMed and MEDLINE for studies published in the past 20 years evaluating the effects of a predominantly or exclusively WFPBD, alone or combined with other lifestyle factors, on neuroimaging biomarkers. Selected studies were grouped into three domains: (1) demyelinating disease, (2) dementia and Alzheimer's disease, (3) cognitive aging and cerebrovascular burden. The dataset comprised heterogeneous study designs and follow-up durations, including randomized-controlled trials (RCTs; n = 9; 14 days - 3 years), longitudinal observational studies (n = 7; 2-20 years), and cross-sectional studies (n = 6). Observational evidence suggests associations between plant-based dietary patterns and favorable neuroimaging outcomes, whereas RCTs have generally not confirmed these effects. Residual confounding and healthy user bias are potential limitations. Dietary patterns aligned with a WFPBD may be important components of broader lifestyle interventions supporting brain health. Confirming observational findings will require adequately powered randomized trials with standardized neuroimaging endpoints and well-designed dietary interventions.