The function of water and its importance

Water is an essential element of our body, a fundamental component for life itself.

The human being is made up of about 80% of liquids: it therefore appears clear that good hydration is the basis of survival and psychophysical well-being.

The functions of this important element are innumerable:

  1. Acts as a solvent in metabolic reactions;
  2. Regulates cell volume and body temperature;
  3. It allows the transport of nutrients and promotes digestive processes;
  4. Removes metabolic waste;
  5. It keeps the anatomical areas lubricated.

Furthermore, good hydration is also important for the cardiovascular system: the presence of a correct amount of water reduces the viscosity of the blood and the risk of thrombus formation, the magnesium contained in it promotes the relaxation of heart muscle cells, while the calcium is involved in blood clotting, reducing the risk of heart attack.

It is therefore essential to guarantee the body the right amount of fluids, and we can do this in several ways.

80% of the water is introduced through what we drink, and the remaining 20% ​​from solid foods. When in excess it is then eliminated through urine, sweating, perspiration and faeces.

With rising temperatures, especially in summer or in very hot countries, maintaining proper hydration becomes of central importance for the well-being of our body. In fact, as the temperature increases, the dispersion of heat and the relative loss of liquids and electrolytes also increase. Our thermoregulation, which takes place to disperse heat and reduce body temperature through sweating, a mechanism that is also established during sports activities, requires a correct level of hydration to function efficiently: in fact, water is needed to activate everyone. those compensatory mechanisms to be able to bring the internal temperature back to natural physiological conditions (about 37 ° C).

What is dehydration and what risks it entails

Dehydration refers to a reduction in the body's volume of water, often accompanied by the loss of electrolytes such as sodium, potassium and chlorine. It is a clinical condition that can occur when the loss of fluids is greater than the intake; therefore, simply when we ingest less water than our body uses.

We can distinguish 3 types of dehydration: hypertonic, isotonic and hypotonic.

Hypertonic dehydration is characterized by an increase in plasma sodium levels and hyperosmolarity: it is the consequence of the loss of pure water, of hypotonic liquids or of a reduction in water intake. In practical terms, it is often linked to excessive sweating and subsequent drop in plasma volume.

Isotonic dehydration usually follows vomiting or diarrhea, and is the loss of water and electrolytes in balanced proportions. It occurs precisely when liquids with a composition similar to that of plasma are lost.

By hypotonic dehydration , on the other hand, we mean a drop in plasma sodium levels and a reduction in osmolarity, and it is secondary to a loss of fluids with excess sodium. It usually occurs as a consequence of the abuse of diuretics or rehydration with low sodium water, especially in summer.

There are also various risk factors that predispose to dehydration and the main one is certainly age. In the elderly, in fact, the stimulus to the perception of thirst tends to decrease naturally, making them an easy target of dehydration. This is followed by prolonged exposure to the sun, too humid or too dry environments, intense physical activity or the presence of ailments such as fever and / or dysentery.

When we are dehydrated, or in any case when our level of hydration is below the standards required by our body, we risk developing various ailments. The most common are intestinal problems, cardiac fatigue, decreased fatigue tolerance and, in the case of low-calorie diets, reduced management of calorie reduction.

Symptoms of dehydration

When the organism loses a greater quantity of liquids than its intake, symptoms such as weakness, cramps, loss of lucidity, irritability, up to the more well-known "heat stroke" can rapidly appear. We must not rely exclusively on the perception of "thirst": often, in fact, the stimulus comes when we are already partially "dehydrated". Drinking only when the sensation of thirst is present can be counterproductive, precisely because feeling thirsty is already an alarm bell in itself: it indicates that the water balance is at a loss. The urge that drives us to drink is regulated by an area located in the hypothalamus, called the "thirst center", which is stimulated when blood volume and pressure decrease. This decrease is already due to dehydration, and this is why it is very important not to wait until you are thirsty to drink. Symptoms of dehydration increase based on the percentage of water lost through sweating or loss of heat. The more water we lose, the greater the perceived symptoms, up to the possibility of developing even very serious events. This obviously takes place in order to maintain correct thermoregulation in relation to body weight.

Below, we illustrate the relationship between the percentage of dehydration and symptomatic manifestations:

1% - Effects on the body's physical activity and performance;

2% - Alterations of thermoregulation and plasma volume - Sense of thirst;

5% - Cramps, asthenia, irritability;

7% - General malaise, intense weakness, hallucinations;

10% - Real risk of onset of heat stroke - collapse - mortality risk.

How to maintain a correct hydro-saline balance

Assuming that there is no ideal quantity of water to take, which is therefore good for everyone, and that the water supply should always be adjusted according to the individual subject due to different climatic conditions, energy expenditure and electrolyte intake, we can say that in normal conditions the daily water requirement is about 30ml per kg of body weight, or 1ml for each kcal taken. In practical terms, you should drink at least 1,5lt of liquids through beverages, always preferring the consumption of still water.

However, this is not enough to ensure proper hydration: fluids are as important as the mineral salts consumed through food. The contribution of sodium chloride, magnesium, potassium and other precious micronutrients is not to be underestimated.

These elements are fundamental for the natural development of biochemical reactions and physiological processes of our organism. Therefore, taking the right amount of salt, in a balanced diet, leads not only to a better distribution of intra and extra cellular fluids, but also to less water retention and heaviness, especially in the leg area. Furthermore, thanks to its influence on blood pressure, the right amount of salt also fights the feeling of fatigue and tiredness.

Hydration for the summer

In summer the risk of dehydration is at its highest level, because the increase in temperatures is linked to excessive sweating. A minimal loss of liquids, corresponding to only 1% of our body weight, is enough to compromise our psychophysical performance and jam the physiological mechanisms. It is necessary to drink in larger quantities, even reaching a total of 3-4 liters per day, especially in the case of physical activity.

These liquids can also be increased by consuming fruit and vegetables. In fact, the variety of fresh foods that high temperatures offer us allow our body to have constant hydration, rich in mineral salts and water-soluble vitamins.

All this is necessary because during the hot periods the organism puts in place a series of thermo-dispersive mechanisms, as well as suspending some metabolic processes necessary for the optional thermogenesis to take place. Skin vasodilation, increased sweating and increased frequency and depth of breathing are some of these mechanisms, which aim to increase the dispersion of heat through evaporation. Thermoregulation is a process that is often involuntary: especially in mammals, it is the intervention of the hypothalamic regulatory center, which captures and processes the signals coming from the cutaneous and central thermoreceptors, to coordinate the most adequate physiological response to maintain the body temperature around the usual 37 ° C.

The elderly, due to the decreased perception of thirst and difficulty in drinking the necessary quantities of water, tend to become dehydrated much more easily. Consequently, as already described above, it is important to prevent this situation, even by taking small sips of water distributed throughout the day or by increasing the intake of natural fruit juices and vegetable purees.

In conclusion, we can say that water remains one of the main sources of life, and it is very important for the body to be able to maintain a good level of hydration, regardless of climatic conditions and energy expenditure. Getting used to sipping a drop of water several times during the day instead of waiting for the sense of thirst will avoid dehydration and all the discomforts it entails, improving mood, energy and performance in general. A useful advice could be to include the consumption of a glass full of water at every meal or snack: if we think about it, in fact, 125-200 ml of water 4-5 times a day are already an excellent starting point to support our hydration!

Furthermore, being properly hydrated allows us not to confuse hunger with thirst, two sensations that are often perceived in the same way, while it is of great importance to know how to distinguish them. We can also say that drinking two glasses of water before each meal, in order to fill the stomach, allows us to correctly manage the feeling of satiety, as well as favoring efficient digestion by gastric juices.



Giada Barca

Nutritional Sport Cosultant

The College of Naturopathic Medicine