It is well known that what we eat affects our physical and emotional wellbeing, but more scientific evidence is needed to determine which dietary patterns are beneficial for our mental health and why. This is the aim of the BEETHOVEN project (an acronym for Brain, Environment and Ecosystems Through Holistic Omics and Validated Evidence-based Nutrition guidelines).

BEETHOVEN will combine a review of the existing scientific evidence with preclinical animal studies and clinical trials in humans to identify which dietary patterns may help prevent conditions such as depression and anxiety and to better understand the mechanisms underlying this relationship. The ultimate goal is to develop a European evidence-based nutrition guideline and facilitate its implementation in different settings, particularly healthcare. Funded by Horizon Europe, the project began on 1 September 2026 and is expected to run until August 2030.

The initiative brings together 13 institutions from nine countries with diverse dietary patterns (Austria, Germany, Greece, the United Kingdom, Israel, Belgium, Sweden, Finland and Spain). One of the participating institutions is the Institut d’Investigació en Atenció Primària Jordi Gol (IDIAPJGol), through the SINCRONITZA research group, part of the Terres de l’Ebre USR. Its principal investigator, biologist and nutritionist Noèlia Carrasco, highlights that IDIAPJGol is the only primary care institution represented in the project.

A prominent role

The institute will lead a review of the existing evidence on dietary patterns and mental health, focusing primarily on depression and anxiety. IDIAPJGol will also play a prominent role in conducting the clinical trial. “We want to design and evaluate the effectiveness of a nutritional intervention in primary care that can help reduce the risk of anxiety and depression and alleviate symptoms when they are already present,” explains Carrasco.

The Catalan centre will also contribute to developing the guideline. The SINCRONITZA researcher explains that “we are leading the first task, which involves searching for all the biomedical evidence available at that point in time, both evidence that has already been reviewed in the previous work packages and new evidence generated by the project itself, in order to determine what biomedical evidence exists on which recommendations should be included in the guideline”.

Finally, IDIAPJGol will contribute to disseminating the results and training healthcare professionals, who will subsequently transfer this knowledge to the population.

Growing awareness

Despite the evidence that nutrition has an impact on people’s mental health, “its role may have been underestimated for many years,” says Carrasco. “Very little time is devoted to nutrition in Medicine or Nursing degrees, where there are few nutrition credits, although in recent years there has been growing awareness of the importance of lifestyle for health.”

The researcher from the Terres de l’Ebre USR points out that “when someone goes to a primary care centre or even a more specialised mental health service, they are almost never asked what they eat or what their lifestyle is like, and perhaps that would be a good place to start”.

Carrasco adds that “if healthcare professionals took the potential impact of lifestyle interventions seriously, they would have enormous capacity to make a difference”. However, she explains, these interventions need to be implemented properly. “We cannot simply recommend that someone follow a healthy diet; we need to teach them how to do it and how to put it into practice. In this respect, we are fortunate to have new professionals joining primary care centres, particularly dietitians and nutritionists, although there are still not enough of them and their range of services remains limited.”

In recent years, the number of studies examining the relationship between diet and mental health has increased considerably. Carrasco notes that healthy dietary patterns, such as the Mediterranean diet, may be associated with better mental health or a lower risk of depression, for example. In any case, more studies are still needed to confirm these findings. “What we do not yet know is what the main mechanisms involved are and which of them could be modulated through diet: whether through anti-inflammatory or immune mechanisms, the gut–brain axis, or other pathways.”

The researcher stresses that “we need to better understand what these mechanisms are, on the one hand, and, on the other, what different diets and dietary patterns that have produced positive results in terms of prevention and mental health outcomes have in common”. This, she adds, will make it possible to develop recommendations for the guideline that can be applied across different geographical areas and population groups.

A healthy lifestyle

It is well established that physical activity and sleep quality also have an impact on mental health. One of BEETHOVEN’s challenges is to control for these other factors and focus specifically on the role of diet.

“When we were preparing the proposal, we insisted strongly on including physical activity and sleep quality as well,” explains Carrasco. She adds that “our research group, SINCRONITZA, focuses precisely on this area—lifestyle—but takes into account three pillars: diet, physical activity and chronobiology”. Ultimately, however, the project focuses exclusively on the nutritional dimension in order to generate new, specific evidence. This makes it important to put mechanisms in place to control for factors that are unrelated to nutrition. “In the clinical trial, we will collect all the data on sleep quality and physical activity among the participants so that, when we carry out the statistical analysis, we can take these confounding factors into account and determine the actual impact of the nutritional component alone.”

The project’s final output will be a guideline and a training programme aimed at healthcare professionals, so that they can take nutritional factors into account when addressing mental health. “The initial idea is that, when someone comes to a consultation and starts explaining that they are experiencing anxiety or feeling somewhat depressed, or when there is a risk of developing a mental health problem, the healthcare professional can assess whether it would be appropriate to refer them to a dietitian-nutritionist to review their lifestyle, particularly their diet, and provide recommendations and advice to help them start making these changes,” concludes Carrasco.

The BEETHOVEN project was officially launched on 1 September in Krems an der Donau (Austria), and the project’s final meeting is expected to be held at the IDIAPJGol headquarters in 2029.