Can a poor quality diet cause brain changes associated with depression and anxiety? This is how he maintains it an international study published in the magazine ‘Nutritional Neuroscience’. The doctor Francisco Botellacoordinator of the Nutrition Area of the Spanish Society of Endocrinology and Nutrition (SEEN), analyzes the conclusions for EL PERIÓDICO DE ESPAÑA and is cautious: So far the studies remain “indirect”. As a line of research, for years specialists have focused on the changes that, different nutrients cause brain neurochemistry. “It is a very suggestive starting point, but we must continue investigating,” he says.
The research reviewed by Dr. Botella, carried out on the diet of 30 volunteers, has been carried out by the University of Reading, the University of Roehampton and Kings College London, in the United Kingdom, and Friesland Campina, in the Netherlands. In the study, brain scans showed changes in neurotransmitters and gray matter volume in people with a poor diet, compared to those who followed a Mediterranean-style diet, considered very healthy.
Mental health
The researchers also found that these changes are related with rumination, which is part of the diagnostic criteria for conditions that affect mental health, such as depression and anxiety. When a person eats a poor quality dietgamma aminobutyric acid (GABA) is reduced and glutamate rises (in both cases neurotransmitters, along with a smaller volume of gray matter) in the frontal area of their brain, they say. This could explain the relationship between what we eat and how we feeldefends the work.
Was there previous evidence in this regard?. “Indeed, for a few years now this topic has occupied a place in our area of interest and has been the subject of various presentations in our Congresses, as advances are made in the knowledge of the brain regulation mechanisms of food intake and the changes that different nutrients cause in brain neurochemistry,” explains the spokesperson for the scientific society.
Indirect studies
However, he qualifies, so far, “the studies are still indirect and are carried out by analyzing, through advanced software of the images obtained by MRI (nuclear magnetic resonance) spectroscopic changes in the presence of different neurotransmitters in different brain areas, related to reward, inhibition and mood control circuits.
In that sense, Dr. Botella assures that they are not “irrefutable evidence to make categorical statements, since, on the one hand, the technique is non-invasive – “as if we wanted to find out during a dark night what the development of a battle is being by analyzing the flashes and flashes that occur“, he clarifies, and is still “imprecise.” On the other hand, there are many, these are healthy volunteers, so “translating the conclusions to people in a situation of diseaseit’s complicated”.
Rumination and food
About the concept of rumination, applied to psychological diagnosis, it should not be understood as something directly related to food or eating; Rather, it refers to the fact of repeatedly thinking about a worry or problem, the specialist indicates.
The ruminations They appear in an intrusive, almost obsessive way and generate great discomfort. Many people describe it as “a broken record that repeats itself constantly”, points out the endocrinologist. In this sense, the authors of the work “use it as another model within the most common mental pathologies to study the effect of more or less healthy eating; in the same way as anxiety, mild depression, etc.”
Sugar and saturated fat
Dr. Piril Hepsomali, from the University of Reading and one of the authors of the research, explained that “people who follow an unhealthy diet –high in sugar and saturated fat– have unbalanced excitatory and inhibitory neurotransmission, as well as reduced gray matter volume in the front part of the brain. This part of the brain is involved in problems mental health such as depression and anxiety.
The author acknowledges that “the exact reason why diet affects the brain in this way is still being investigated and it is possible that obesity and patterns of diets rich in saturated fats cause changes in the metabolism and neurotransmission of glutamate and GABA, as has been shown in animal studies“.
The coordinator of the Nutrition Area of the Spanish Society of Endocrinology and Nutrition insists: this is an association study (type of diet consumed in relation to the presence of what is called ‘most common mental pathologies’). “It is not a prospective or intervention study, so we cannot say whether mood influences the selection of more or less healthy foods or, on the contrary, the choice of less healthy foods. It is what alters the mental state“he concludes.
Fats and cholesterol
On the other hand, although the british study researchers point out that the relationship between poor quality diet and brain health is still being analyzed, they point out that a diet rich in fat and cholesterol It can also cause changes in cell membranes that alter the release of neurotransmitters.
Regarding basic research, this aspect was known, explains Dr. Botella. “Cell membranes contain a large amount of fat (phospholipids) that can be influenced by fatty acids in the diet, altering its flexibility/stiffness properties, interaction with its membrane receptors or with different extracellular molecules“he points out.
Fatty acids
In the case of brainparticularly rich in phospholipids, he adds, the fatty acid composition of the diet will “certainly” influence the release/reuptake of neurotransmitters and, the results of the series of studies Prevention with Mediterranean Diet (PREDIMED), point “in the direction of a beneficial effect of the type of fat we consume on different health outcomes that involve to cerebral and cerebrovascular functioning“.
“Until we have prospective intervention studies with a control group, it is not possible to make categorical statements no specific recommendationsat the moment a very interesting door is opening to investigate the effect of our diet on brain biochemistry, but we are very far from being able to translate its results into practical issues. Scientific research has its procedure and its methodological rigor which, as in this case, cannot necessarily be fast,” concludes the endocrinologist.
The Mediterranean diet pattern has “ample bibliographic support” on positive health results, says the endocrinologist
One of the best known aspectsconcludes, is that the Mediterranean diet pattern has “ample bibliographic support” on positive health outcomes, which includes a high intake of vegetables, fruits, nuts, legumes, cereals, fish and olive oil, and a moderate intake of meat, dairy products and, as little alcohol as possible, as the best diet to take care of our brain.