A study led by CIBER (Centro de Investigación Biomédica en Red) and the Girona Biomedical Research Institute(IDIBGI) directly links ultra-processed food with depression, the volume of gray matter in the mesocorticolimbic brain circuit and inflammation parameters. The collaborative research work has been led by two areas of CIBER, CIBERSAM (Mental Health) and CIBEROBN (Physiopathology of Obesity and Nutrition). This study aims to shed light on the possible adverse effects that the consumption of ultra-processed foods may have on mental health and the brain.
Depressive disorders are one of the most common psychiatric disorders worldwide, with an estimated 300 million people living with depression (Stringaris, 2017). It is estimated that this type of disorder will be the leading cause of illness by 2030. On the other hand, it is indisputable that depression severely limits the psychosocial functioning of sufferers and significantly decreases their quality of life.
Most ultra-processed foods have a lower nutrient density, but a higher energy concentration compared to unprocessed foods. In addition, they are rich in saturated and trans fatty acids, added sugars and salt, and are poor in protein, dietary fiber and micronutrients. These types of products often contain additives to intensify their sensory qualities and mimic the appearance of minimally processed foods, making them edible, tasty, highly appealing and potentially addictive.
The principal investigators of the study, Oren Contreras-Rodríguez and José Manuel Fernández-Real, mention that: "the study aimed to determine the relationship between ultra-processed food consumption and depressive symptoms, as well as to provide new data on the association between the consumption of these products and brain gray matter volumes in 152 adults. We also sought to explore interaction effects with obesity, as well as to assess whether inflammatory biomarkers mediate these previous associations. “They also add, "As a working hypothesis, we expected that higher ultra-processed consumption would be associated with an increased risk of depressive symptoms and lower gray matter volume in the amygdala and frontal regions, especially in participants with obesity, as they tend to be characterized by higher ultra-processed consumption. Indeed, the results confirmed our hypothesis".
One of the main results is the association between a higher consumption of ultra-processed foods and a greater presence of depressive symptoms, as well as a lower volume in brain regions involved in processing reward and monitoring conflict, essential aspects in decision making, including food decisions. It also highlighted the mediation of white blood cell count in the association between ultra-processed food consumption and depressive symptoms. The association between the consumption of these products and depressive symptoms was especially notable in the group with obesity (58.6% of the participants), which started from a higher presence of depressive symptoms compared to the group without obesity.
In conclusion, the research supports previous evidence linking ultra-processed food consumption to the risk of depressive disorder, and provides new data associating it with changes in the structure of specific brain networks. In addition, it shows that these associations could be dependent on the presence of obesity and the levels of peripheral inflammation.
Researchers from the Barcelona Public Health Agency and the Sant Pau Research Institute also collaborated in the study.
Study methodology:
Focusing on the participants, 233 individuals were recruited to be part of this cross-sectional study. After discarding those with defective or missing magnetic resonance imaging (MRI) and those who did not complete the food frequency questionnaire, a final sample of 152 participants was obtained
Focusing on the consumption of ultra-processed foods, information on diet over the past year was collected using validated food frequency questionnaires. The NOVA food classification system was used to identify ultra-processed foods and beverages according to their degree of processing. Finally, the percentage of ultra-processed consumption in the overall diet was also calculated.
On the other hand, depressive symptoms were assessed and structural magnetic resonance imaging was performed. Finally, several metabolic parameters and inflammatory biomarkers were measured, such as white blood cell count, lipopolysaccharide binding protein and C-reactive protein.
ARTICLE REFERENCE
Oren Contreras-Rodriguez, Marta Reales-Moreno, Sílvia Fernández-Barrès, Anna Cimpean, María Arnoriaga-Rodríguez, Josep Puig, Carles Biarnés, Anna Motger-Albertí, Marta Cano, José Manuel Fernández-Real. Consumption of ultra-processed foods is associated with depression, mesocorticolimbic volume, and inflammation, Journal of Affective Disorders, Volume 335, 2023, Pages 340-348, ISSN 0165-0327, https://doi.org/10.1016/j.jad.2023.05.009.
About the CIBER
The Centro de Investigación Biomédica en Red (CIBER) is a public consortium attached to the Instituto de Salud Carlos III (Ministry of Science and Innovation) and is co-financed by the European Regional Development Fund (ERDF). Its objective is to promote research of excellence in biomedicine and health sciences carried out in the National Health System and in the Science and Technology System. At present, the CIBER has more than 500 research groups and a staff of nearly 6,000 people between assigned and contracted research personnel, belonging to more than 100 consortium institutions.
Dr. Oren Contreras-Rodríguez is a researcher in the Medical Imaging group of IDIBGI, as well as a member of CIBERSAM, linked to the group led by Dr. José Manuel Menchón (IDIBELL). Dr. José Manuel Fernández-Real is the head of the Nutrition, Eumetabolism and Health research group at IDIBGI and CIBEROBN.
