A protein-enriched Mediterranean diet may improve nutrition and cognitive performance in older adults at risk of undernutrition and cognitive decline, according to newly published results from the PROMED-EX randomized controlled trial.
Published online in The American Journal of Clinical Nutrition on August 14, 2026, the study followed 105 community-dwelling older adults for six months, examining whether targeted dietary changes—with or without home-based exercise—could support healthier aging.
Study Tested Diet, Exercise and Standard Advice
Participants had an average age of about 68 years, and 69% were women. All were considered at risk of both undernutrition and cognitive decline.
Researchers randomly assigned them to one of three groups: a protein-enriched Mediterranean diet plus home-based exercise, the same diet without the exercise programme, or a control group that received a healthy-eating leaflet.
The Mediterranean-style intervention emphasized improving overall diet quality while ensuring adequate protein intake—an important consideration as people age and become more vulnerable to loss of muscle and poor nutritional status.
Nutritional Status Improved Significantly
After six months, nutritional status improved significantly in both Mediterranean-diet intervention groups compared with the control group.
Using the Mini Nutritional Assessment scale, researchers reported an adjusted improvement of 2.7 points for the diet-only group and 2.9 points for the diet-plus-exercise group compared with controls.
Diet quality also improved substantially in both intervention groups.
The findings are particularly relevant because undernutrition among older adults can contribute to frailty, muscle loss, reduced independence and poorer overall health.
Cognitive Performance Also Improved
Researchers found encouraging results for cognition.
Compared with the control group, overall neurocognitive test scores improved by 0.3 standardised units in the diet-only group and 0.2 in the diet-plus-exercise group.
The findings do not prove that a protein-enriched Mediterranean diet can prevent dementia. However, researchers said that correcting undernutrition could potentially help slow cognitive decline while supporting physical health and quality of life during aging.
Did Exercise Provide Extra Benefits?
Interestingly, adding exercise did not produce clearly greater improvements in the study’s main nutrition or cognitive outcomes.
One important explanation is that adherence to the home-based exercise programme was low, making it difficult to determine the full potential benefit of combining the two interventions.
Even so, researchers observed additional improvements in some measures of physical performance and health-related quality of life among participants receiving the exercise intervention.
Why Protein Matters as We Age
Maintaining adequate protein intake becomes increasingly important with age because older adults are vulnerable to declining muscle mass and strength.
A protein-enriched Mediterranean eating pattern can combine protein sources with many of the foods traditionally associated with the Mediterranean diet, including vegetables, fruits, legumes, whole grains, nuts and olive oil.
The goal is not simply eating more protein, but maintaining adequate nutrition within a balanced dietary pattern.
What the Study Means for Healthy Aging
The PROMED-EX findings suggest that nutrition could be a valuable and modifiable part of healthy-aging strategies, particularly for older people already at risk of poor nutrition and cognitive deterioration.
However, the trial was relatively small, involving only 105 participants, and researchers say larger and longer studies are needed before determining whether these improvements translate into lasting protection against cognitive impairment.
For now, the strongest conclusion is encouraging but measured: a protein-enriched Mediterranean diet improved nutritional status and showed promising cognitive benefits in at-risk older adults, while exercise may offer additional physical and quality-of-life advantages.
About the Author
