Follow one Mediterranean diet It could become an important ally in keeping your mind sharp. as the years go by. Beyond its known effects on the heart and metabolism, this traditional eating pattern in Spain is now linked to a slower progression of cognitive decline in older people with metabolic problems.
An investigation developed in the field of Rovira i Virgili University (URV)The Institut de Recerca Biomèdica CatSud, the Instituto de Investigación Sanitaria Pere Virgili (IISPV) and the area of Physiopathology of Obesity and Nutrition of CIBER (CIBEROBN) contribute new evidence that The gut microbiota plays a key role in this protectionThe study suggests that certain gut bacteria, favored by the Mediterranean diet, could help preserve cognitive function during aging.
URV | viernes, 23 de enero de 2026
A large study with overweight or obese older adults
The study was conducted with 746 older adults that presented overweight or obesity and metabolic syndromeThat is, a set of abnormalities—such as hypertension, excess abdominal fat, or glucose abnormalities—that increase the risk of cardiovascular disease and diabetes. All of them had a high cardiometabolic risk and were followed for a period of six years.
The research team systematically evaluated Three major aspects: the degree of adherence to the Mediterranean diet, the composition of the gut microbiota, and the evolution of cognitive functionTo this end, detailed data on eating habits were collected, fecal samples were analyzed to characterize the bacteria present in the gut, and neuropsychological tests were applied to measure abilities such as memory, attention, and reasoning.
The results, published in the scientific journal BMC Medicine, indicate that People who more strictly followed the Mediterranean diet had a more favorable gut microbiota and, at the same time, a slower cognitive decline over the follow-up period. In contrast, those who deviated from this dietary pattern showed less positive cognitive evolution.
The work falls within the framework of the consortium PREDIMED PlusThis is part of a large-scale, multicenter study conducted in Spain that examines the impact of the Mediterranean diet and lifestyle on long-term health. Within this context, the new publication focuses specifically on the relationship between diet, gut microbiota, and brain function.
The microbial footprint of the Mediterranean diet
One of the aspects that the team highlights as most innovative is the identification of a “microbial footprint” associated with the Mediterranean dietThis concept refers to a characteristic set of gut bacteria whose presence and abundance are linked to greater adherence to this dietary pattern. Furthermore, the authors relate this signature to detectable changes in the microbiota which could partly explain the observed effects.
In practice, this footprint functions as a new microbiota-based biomarkerWhen certain groups of microorganisms associated with the Mediterranean diet predominate, a slower rate of cognitive decline is also observed. According to the authors, this finding provides valuable clues about the biological mechanisms that could explain why this type of diet is beneficial for the brain.
Predoctoral researcher Jiaqi Ni, first author of the URV paperShe emphasizes that the data obtained “demonstrate that the gut microbiota is a key element in the cognitive benefits of the Mediterranean diet.” According to the author, some bacteria linked to greater adherence to this diet “could offer some protection against the decline of mental functions.”
The professor from the URV Jordi Salas-Salvadó, director of the study And a researcher from CIBEROBN, points out that recognizing this microbial fingerprint “opens up new opportunities to design nutritional interventions or even microbial ones” aimed at promoting healthier cognitive aging. The team believes that, in a context of increasing life expectancy and a growing prevalence of dementia, these strategies may be especially relevant.
Likewise, the researchers from the URV Nancy Babio and Stephanie K. NishiResearchers from the Department of Biochemistry and Biotechnology emphasize the importance of these results in societies like Spain, where the population is aging rapidly. In their opinion, improve the overall quality of the diet It is a relatively simple and accessible tool, with a real potential impact on the brain health of older people.
The gut-brain axis in the spotlight
In recent years, numerous scientific works have brought to light the existence of the so-called gut-brain axisA two-way communication system through which gut bacteria can influence the central nervous system. These microorganisms participate in food digestion, play a role in the immune response, and produce compounds that can reach the brain.
These substances include, for example, metabolites derived from dietary fiber, vitamins, and other signaling molecules These microorganisms contribute to modulating inflammatory processes, mood, and even cognitive performance. Therefore, the composition of the microbiota is not a neutral element, but rather part of a complex network of interactions that affects the organism as a whole.
The Mediterranean diet, characterized by a high consumption of fruits, vegetables, legumes, whole grains, extra virgin olive oil, nuts and fishAnd due to a lower presence of processed products and red meat, it seems to create a particularly favorable environment for this intestinal microbial ecosystem.
The work led by the URV and the IISPV shows that People who adhere more closely to this dietary pattern have a more diverse and healthier microbiota profileThis diversity is, in turn, associated with a better ability to produce compounds beneficial to brain health, which would fit with the slower rate of cognitive decline observed during follow-up.
The combination of these findings reinforces the hypothesis that It is not just one specific food that makes the difference, but the overall dietary pattern.which modulates the intestinal environment and, through it, could influence the evolution of functions such as memory or attention.
Implications for aging in Spain and Europe
The study takes place in a context in which population aging and the increased prevalence of dementia These are significant challenges both in Spain and in the rest of Europe. Projections indicate that the number of people with mild cognitive impairment or dementia will continue to grow in the coming decades, with a considerable health, social, and economic impact.
From this perspective, Having preventive strategies based on lifestyle is especially attractiveThe Mediterranean diet, being part of the culinary tradition of many southern European countries, is presented as a realistic option for the general population, provided that its maintenance is encouraged over more Western and processed eating patterns.
The authors of the study point out that, although the research has focused on older people who are overweight or obese and have metabolic syndromeThe results could inspire broader nutritional recommendations to promote healthy cognitive aging. However, the authors note that this is an observational cohort study, so it does not establish a definitive cause-and-effect relationship, but rather strong associations that will require further exploration.
In any case, the fact of having identified a specific microbial fingerprint linked to the Mediterranean diet This opens the door to using this biomarker in future research. For example, it could be used to assess whether dietary or probiotic interventions can modify the microbiota in the desired direction and whether these changes translate into measurable benefits for cognitive function.
Institutions such as the URV, the Institut de Recerca Biomèdica CatSud, the IISPV and the CIBEROBN agree that it is necessary to continue investing in this type of project, that connect nutrition, microbiology, and neurologyThe full reference for the article, authored by Ni J, Hernández-Cacho A, Nishi SK, Babio N, and Salas-Salvadó J, among others, is: “Mediterranean diet, gut microbiota, and cognitive decline in older adults with obesity/overweight and metabolic syndrome: a prospective cohort study,” published in BMC Medicine (2025;23(1):669, doi: 10.1186/s12916-025-04488-y).
Taken together, the results of this work suggest that Maintaining a Mediterranean diet could help preserve brain health through favorable changes in the gut microbiotaespecially in older adults with cardiometabolic risk. While not presented as a miracle cure, evidence suggests that paying attention to diet, within the Mediterranean pattern, could be another piece in the puzzle of the healthiest possible cognitive aging.
