Research Too much salt damages our brain?

How does the increased consumption of salt affect the brain and memory??

Salt contains various essential minerals and trace elements that are important to the human body. The problem is that too much salt is harmful. Researchers have now discovered that salt can even have a negative impact on our brain. A high-salt diet can lead to cognitive decline as well as high blood pressure, vascular inflammation and cardiovascular disease.

Cornell University's Weill Cornell Medicine researchers have discovered a previously unknown effect of the high-salt diet. Salt causes cognitive decline in the brain. The physicians published the results of their study in the journal "Nature Neuroscience".

Dietary guidelines advise against high salt intake. Researchers found that over-consumption of salt can cause brain damage. (Image: HandmadePictures / fotolia.com)

How does too much salt affect the human body??

A diet with too much salt can lead to various known negative effects on the human body. These include, for example, high blood pressure, vascular inflammation and cardiovascular diseases. A previous study has already shown that heart failure threatens when salt intake is too high. Maybe even the puberty is delayed. However, it was previously unknown that too much salt also seems to have direct effects on human cognitive performance.

Physicians are studying the effects of a high-salt diet on mice

In their recent study, mice researchers investigated whether a high-salt diet affects the blood flow to the brain and the cognitive performance of the animals. The mice were given a special diet containing four to eight percent saline in the experiment. This is similar to a high-salt diet in humans, explain the experts.

After only eight weeks, the first changes were observed

The result was clear. Already after a short period of eight weeks, the diet caused significant changes in the brain of the animals. The cerebral cortex of the mice was perfused about 28 percent worse, the scientists say. This could be determined by a so-called magnetic resonance tomography (MRI). It also affected the hippocampus, which is important for memory. The physicians found that blood flow in the hippocampus was reduced by 25 percent.

The mental performance of the mice worsened due to the high consumption of salt

With the help of two memory tests, the scientists also found that the mental performance of the animals had deteriorated. The animals could no longer remember whether they had ever seen an object or not. Each object was studied intensively and examined as if the mice had never seen it before. This effect did not occur in the animals of the control group, the authors explain.

Deterioration of cognitive performance affected old and young mice

Further deficits were also shown in a test in which the mice had to run through a labyrinth. The animals with the high-salt diet needed much longer to find the outcome despite a three-day learning phase. This may indicate a deficit in spatial memory, say the medical profession. Such deterioration of cognitive performance was found in young and old mice.

What is the cause of the detected neurological effects?

Of course, the scientists tried to find out what is causing these neurological deficits. The physicians found no evidence of increased activity of inflammatory enzymes, explains author Giuseppe Faraco. Inflammatory changes in the cerebral vessels, which lead to reduced blood flow and thus affect the functions of the brain, could thus be excluded. The physicians found, however, that in the intestine of animals with a high-salt diet, the TH17 immune cells increased. This then led to increased release of the messenger interleukin-17 (IL-17). This messenger substance passes through the blood into the brain, where it affects the supply of blood vessels with nitric oxide, explain the doctors. Nitric oxide is important for good blood flow to the brain.

Diet with too much salt damages the vessels of the brain

Such a connection between the intestine and the brain was previously unknown, say Cornell University scientists. The compound can cause a diet with too much salt damage the vessels of the brain, as a result, that the brain function and cognitive performance are impaired. The blood pressure has no effect, add the experts.

How much salt should people eat each day??

Presumably, the observed effect can occur in humans. The mechanisms involved are also present in humans, this could be observed in initial cell culture experiments. Even if you do not suffer from high blood pressure, you should still limit the intake of salt. It is recommended by the World Health Organization experts on this subject that people should not consume more than six grams of salt per day.

The cognitive losses are reversible

However, the authors also stated that the cognitive decline found in the study can be reversed by consuming too much salt. If the experimental animals returned to a normal diet with less salt over a period of a few weeks, the memory performance of the mice improved again. (As)