Photo by Emmy Smith on Unsplash / Unsplash
By now we all know about the devastating consequences related to excessive salt intake in the diet. The lifestyle of modern society that is characterized by following a diet high in processed foods, in recent years has caused a worrying increase in cases of hypertension and cardiovascular diseases. However, recently American researchers, in a one-of-a-kind study, explored the relationship between neural activity and blood flow deep in the brain. Specifically, they analyzed how the brain is affected by salt intake and among their most important findings they discovered: increased cognitive decline and this may be associated with a higher risk of developing Alzheimer’s.
The study, published in the journal Cell Reports, examined how blood flow to the hypothalamus changes in response to salt intake. According to statements by one of the study authors; Javier Stern, professor of neuroscience on the university team: “When people eat salty foods, the brain detects them and activates the neurons that trigger the release of vasopressin. It is an antidiuretic hormone that plays a key role in maintaining the proper concentration of salt in the body. ” However, unlike previous studies that have observed a positive link between neural activity and increased blood flow, this new study showed a decrease in blood flow as neurons fired in the hypothalamus.
According to Stern, the findings took the team of scientists by surprise as vasoconstriction, which is the opposite of what most people describe in the cortex in response to a sensory stimulus. Usually, a reduction of blood flow in the cortex is observed in the case of diseases such as Alzheimer’s or after a stroke or ischemia.
The team named the phenomenon “Reverse neurovascular coupling”, or a decrease in blood flow leading to hypoxia – lack of oxygen. They also observed other differences: for example, in the cerebral cortex, vascular responses to stimuli are highly localized and dilation occurs rapidly. However, in the hypothalamus the response was diffuse and occurred slowly, over a long period of time, and the main reason is that elevated sodium levels remain for a long time. According to Stern: “We believe that hypoxia is a mechanism that strengthens the ability of neurons to respond to sustained stimulation of salt, allowing them to remain active for a prolonged period.”
While much research work remains to be done to understand the complex mechanisms of excess salt in brain health and various cognitive functions, the findings raise interesting questions about how hypertension can affect the brain. It is believed that between 50 and 60% of hypertension is triggered by excessive consumption of salt. These types of studies come to take our salt intake much more seriously, the reality is that on many occasions we are not aware of all the foods of daily consumption that contain hidden sodium.
Finally, the revelations are overwhelming: if you chronically ingest a lot of salt, you will have hyperactivation of vasopressin neurons. This mechanism can then induce excessive hypoxia, which could lead to tissue damage in the brain. The good news is that by better understanding the complex process associated with a high sodium diet, we can design new targets to stop this hypoxia-dependent activation and perhaps improve outcomes for people with salt-dependent high blood pressure. .
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Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.