Background: Cognitive decline—worsening memory and more frequent memory loss or confusion—affects 10% of all US adults aged 45 and older. Incidence is higher—11.4%—among Hispanic and Latino Americans. In some cases, cognitive decline may be an early sign of dementia.
Close adherence to the Mediterranean diet (MeDi) is associated with a reduced risk of dementia and cognitive decline. The MeDi emphasizes fresh fruits, vegetables, whole grains, beans, legumes, nuts, low to moderate amounts of dairy, eggs, fish, and poultry, and olive oil as the primary fat source.
Researchers have attributed the MeDi’s brain benefits to its cardiovascular effects, such as lower blood pressure, reduced diabetes risk, and improvements in blood vessel function and cholesterol levels. The first large-scale study of the MeDi in Hispanic and Latino Americans investigated whether the MeDi’s brain benefits are independent of its cardiovascular effects.
Preliminary findings from this 10-year study of 2,774 participants (44% men, 56% women; average age 64 at follow-up) were presented at the recent conference of the American Stroke Association, February 5–7, 2025.
Methods: At an initial visit, each participant reported their food intake during the previous 24 hours and received a score (0 to 9), indicating how closely their diet corresponded to the MeDi. Average MeDi score was 5. Ten years after the baseline visit, investigators obtained a brain scan via MRI (magnetic resonance imaging) for each participant.
The main outcome evaluated in the study was white matter integrity (WMI) and volume. The white matter of the brain (as opposed to the gray matter) consists of bundles of nerve fibers that, crucially, communicate information to different parts of the brain. WMI and volume are markers of the strength of those connections in the brain. MRI scans provide clear, detailed cross-sections of the brain, showing white matter and gray matter.
To account for the impact of cardiovascular benefits, the study also asked participants about multiple practices associated with heart health: regular exercise; healthy diet; not smoking; weight maintenance; and maintaining healthy blood pressure, blood sugar, and cholesterol levels.
Results: Participants with higher MeDi scores had stronger connections between regions of the brain (preserved WMI) compared to those with lower MeDi scores. With each point higher in MeDi score, participants’ MRI scans also showed less structural damage to the blood vessels of the brain. After factoring in heart-health practices, the researchers determined that cardiovascular effects alone did not account for all the significant brain benefits of the MeDi.
Conclusion: Eating a Mediterranean-style diet improved brain health and preserved structural integrity in a high-risk population. Even small adjustments in food intake, closer to the MeDi, could help protect against cognitive decline and dementia. The brain benefits of the MeDi extend beyond its well-known cardiovascular effects—more research is needed to identify the brain-protective mechanisms involved.
References: 1. Trifan G, Moustafa B, Issan C, et al. Stroke. 2025(56);Supp 1:Abstract 100. 2. Mediterranean-style diet linked to better brain health in older Hispanic and Latino Adults. February 5, 2025. 3. Wooten KG, McGuire LC, Olivari BS, et al. MMWR Morb Mortal Wkly Rep. 2023;72:249–255.