When we talk about salt in the kitchen, we mean sodium chloride. But talking about the same salt from the point of view of our body, it makes sense to talk about sodium and chlorine separately.
Both of these chemical elements are needed by man primarily for processes that occur at the cell level, and not at the level of whole organs or the whole organism.
Let’s start with sodium, whose role is difficult to overestimate. This metal is involved in processes associated with the electrical potential of the cell membrane.
Let’s start in order. In the intercellular space contains a lot of sodium, and inside the cell – a lot of potassium. Further, it is a little bit more difficult, but – missing details – as a result at the expense of it on a membrane of a cell there is an electric potential and the cell becomes the charged structure.
This is important for very many intracellular processes, but from the point of view of the whole organism, it is more noticeable that cells can control this charge. For example, in nervous and muscle cells there is the ability to propagate or change this charge – so nerve impulses are born.
Accordingly, sodium plays an important role in the development of the nerve impulse and in maintaining the charge at a certain level. As an example of how this works in life: local analgesics block the sodium channels in the nerve fibers, which is why the electric impulse ceases to pass through them – and we cease to feel pain.
And sodium participates in such an important process as osmoregulation. This process is responsible for maintaining the water balance at the level of individual cells.
The meaning of osmoregulation is this. If there is some very strongly concentrated solution in which there is much that is contained, the water will tend to where this solution is concentrated in order to try to dilute it. And if we have a membrane at hand that freely passes water, but hardly passes those substances that are concentrated in the water, we can control the amount of water, in our case – inside the cell and outside.
What does it mean? Cages are, relatively speaking, small bubbles filled with some salts. If we put such a cell in clean water, without salts, then pure water will get inside the cell and the cell will simply burst. In the body this does not happen, in the blood and other tissues we have a certain content of sodium ions, thanks to which the ratio of water inside the cell and outside is more or less uniform and the cells do not burst.
These are examples of how sodium works at the cell level. But how sodium works at the level of the whole organism. It is important to us that the sodium content in the body remains at a certain level. If we consume too much salt, the sodium content inside us increases and the body can begin actively removing sodium due to several different mechanisms, the side effect of which may be an increase in total pressure.
Chlorine is also needed for electrical processes in cell membranes: in many cells, there are special channels for chlorine, opening or closing which the cell affects the potential of the membrane. And this element is very important for the work of the stomach, where hydrochloric acid is formed from it, helping us to digest food.
For daily use, a person needs sodium chloride without impurities. The exception is an iodized salt. Some salt of iodine is added to the food salt because iodine is also very necessary. First of all, the cells of the thyroid gland, which with its help produce certain hormones that regulate various processes in the body. Why was it decided to iodize salt, and not some other product – because it’s cheap and simple, and also because salt is used by a person every day and almost everyone eats it.
But the presence of some other impurities in salt does not bode well. So, some time ago it was fashionable to advertise not sodium, but potassium salts. This is a monstrous story. The use of such salts leads to the fact that the electrical balance on the membrane is disturbed and, in the first place, the cells of the heart can suffer from this.
WHO advises eating 5 grams of sodium chloride per day. It is important to understand that in these 5 grams there is also that salt that we consume in pure form, and salt, which in itself is contained in the products. The WHO norm applies to sodium because there is practically no scarcity and excess of chlorine.
If you are trying to understand how much salt you consume, you need to keep track of how much sodium is contained in the products that you buy. Lack of sodium is difficult, it is found in most foods – in meat, in any vegetables. It is not only in pure vegetable oil or sugar. With a modern diet, if you do not salt food specifically, then a daily dose of sodium a person still get. Moreover, if we become inadequate sodium, our body will start to take out less sodium: the compensatory mechanism will turn on – if we do not get enough of it, then we do not get enough of it. And we need a very long time and systematically under-receive sodium so that it had at least some effect on the body.
But an overdose of sodium will be noticeably faster. In acute and severe overdosage, renal failure is possible. If, for example, one-time eat 6-7 tablespoons of salt, then such a record can lead to rapid death. In this sense, the salt can literally be called a white poison. And if you just eat systematically with high sodium, then, according to most doctors, this leads to a systemic increase in blood pressure. If a person has started to increase pressure, the doctor may also advise lowering the content of salt in the diet.