A study carried out in the Cajal Institute reveals how the consumption of polyphenols in the diet can be associated with a lower incidence of chronic-degenerative diseases. Polyphenols comprise several groups of compounds found naturally in plant-based foods and beverages, and are transformed by the gut microbiota into more bioavailable compounds. The work, which is published in the journal Cerebral Cortex and is led by Herreras’ group from the Cajal Institute (IC-CSIC), in collaboration with researchers from the CIAL-CSIC, indicates that dietary polyphenols could exert beneficial effects by directly modulating the electrical activity of neurons. The neuroprotective effect opens the door to treatments for neurodegenerative pathologies such as Alzheimer’s, Parkinson’s or cerebrovascular accidents.

A compound from the polyphenol family is protocatechuic acid, which is found in a wide variety of foods, especially fruits and vegetables. Its beneficial effects are known and have been tested in the laboratory, including antioxidant, anti-inflammatory, antitumor, immunoregulatory, as well as neuroprotective benefits. It was formerly assumed that these effects were mediated by an action in the vascular system, regulating the supply of blood and nutrients, or directly on neural cells and their metabolic pathways. Incidentally, both cellular and systemic pathways are a direct reflection of the electrical activity of neurons, to which they serve. The electrical activity of certain brain nuclei translates outside and internal stimuli during the processing of information, but this activity can be modulated in a sustained upward or downward manner by neuromodulatory substances, making the person more or less sensitive both to natural stimuli and to conditions that result in damage or dysfunction. These substances are released from other brain cells or from the bloodstream itself, coming, for example, from the diet.

“Until now, it was unknown whether dietary polyphenols could exert beneficial effects by directly modulating the electrical activity of neurons. What has been confirmed in this study is that protocatechuic acid decreases the electrical response capacity of neurons, that is, they become quieter,” explains Óscar Herreras, IC-CSIC researcher. “This – points out the scientist – opens new possibilities to explain and even treat some neurodegenerative diseases since, for example, the decrease in electrical activity and, therefore, the energy consumption of neurons, will reduce the production of free radicals and other pro-inflammatory agents, hence the neuroprotective effect.”

There is still much to investigate, such as knowing how easily polyphenols penetrate the brain and whether it would be possible to direct this protective action to specific areas where it is most necessary. Scientists hope that these findings will prompt more determined action to investigate the effect of dietary components directly on the electrical activity of the brain, the primary cause of the molecular and gene activation of neurons and other brain cells, on the one hand, and behavior and its dysfunctions, on the other. According to the team leader “…electrical activity of the brain is the key to everything. A molecular or cellular deficiency does not matter if the electrical function of neuron populations can be assisted, corrected or substituted by any means.”

Find more information at: https://academic.oup.com/cercor/advance-article/doi/10.1093/cercor/bhad292/7237837