Protein-enriched Mediterranean diet linked to improved nutrition and cognitive function in older adults
A 6-month randomized trial of 105 older adults at risk of undernutrition found that a personalized protein-enriched Mediterranean diet—with or without home exercise—significantly improved nutritional status and cognitive performance compared to standard healthy eating guidance.
Undernutrition in older adults is common yet often overlooked, and is linked to cognitive decline and poor health outcomes. This randomized controlled trial enrolled 105 community-dwelling older adults (mean age 67.7 years, 69% female) who were at risk of undernutrition and cognitive decline.
Participants were randomly assigned to one of three groups: personalized dietary counseling on a protein-enriched Mediterranean diet plus home-based exercise (PROMED-EX), dietary counseling alone (PROMED), or a control group receiving only a healthy eating leaflet (CON). After 6 months, both dietary intervention groups showed significant improvements in nutritional status, measured by the Mini Nutritional Assessment (MNA). PROMED improved MNA scores by 2.7 points and PROMED-EX by 2.9 points, compared to a control decline, both highly statistically significant. Cognitive function also improved, with standardized neurocognitive test scores 0.3 points higher in PROMED and 0.2 points higher in PROMED-EX versus control. Diet quality scores increased substantially in both intervention groups (by ~4 points on a 14-point scale) compared to control. Despite low adherence to the exercise component, the exercise group reported additional benefits in physical performance and quality of life. The study was small and lasted only 6 months, limiting generalizability to longer-term outcomes.
The cognitive improvements were modest in absolute terms—a 0.2–0.3 point shift on a standardized z-score scale—but consistent and statistically significant across both diet-based interventions. Notably, the addition of exercise did not substantially amplify cognitive gains beyond diet alone, suggesting that correcting nutritional deficiency may be the primary driver. The MNA improvements of 2.7–2.9 points represent clinically meaningful movement out of the at-risk nutritional range at baseline (mean 22.5). Secondary findings showed that diet quality increased reliably in both intervention groups by approximately 4 points on the 14-point Mediterranean diet quality score. The mechanism likely involves restoration of protein intake, micronutrient repletion, and reduced inflammation from the Mediterranean pattern. A key limitation is that exercise adherence was unexpectedly low, so the true benefit of combining diet and exercise remains unclear. The 6-month follow-up window also leaves open whether cognitive and nutritional gains persist beyond the intervention period.
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Open in Cadence →References
- Effect of a PROtein-enriched MEDiterranean diet and EXercise (PROMED-EX) on nutritional status and cognitive performance in older adults at risk of undernutrition and cognitive decline: the PROMED-EX randomized controlled trial. — The American journal of clinical nutrition (Read the original)