In the experiment, six-month-old male mice were divided into two groups: one group was fed a regular diet, while the other received a diet containing 8% sodium chloride. After six months, the mice on the high-salt diet exhibited changes such as increased blood pressure, impaired memory, and signs of anxious behavior.
During behavioral tests, the animals on the salty diet displayed avoidance behavior in open spaces and had difficulties recognizing new objects. Analysis of brain tissue showed a reduction in neuron density in the hippocampus—a region responsible for learning and memory.
Furthermore, the scientists discovered changes in gene activity: in the hippocampus, there was increased expression of inflammation-related genes, while genes responsible for cell survival were suppressed. This, according to the researchers, indicates the development of neuroinflammatory processes.
Analysis of the gut microbiome composition also revealed that the high-salt diet significantly altered the ratio of bacteria: the number of certain microorganisms increased, while beneficial bacteria decreased. These changes were associated with inflammatory processes in the brain.
The authors of the study note that excess salt may negatively affect the gut microbiome, and the byproducts of their activity or immune signals may impact the brain, altering gene function and contributing to neuron death.
The World Health Organization recommends limiting salt intake to five grams per day; however, many people, according to experts, exceed this norm by two times.
