If you eat very salty foods you will be very thirsty. In the first 24 hours after ingestion, yes, but then no. This is one of the conclusions reached by German scientists and from Vanderbilt University (Nashville, United States). The reason? Your body feels less thirsty because, faced with excess salt, it begins to conserve and produce more water.
The work, published in the Journal of Clinical Investigation, provides new insights into the body’s response to excess salt in the diet and may provide clues for more effective treatments of three near-epidemic ills that plague developed societies: obesity, diabetes and lifestyle-related heart disease.
Why is it hungry to go overboard with salt?
Textbooks tell us that an excessive intake of sodium chloride requires the body to eliminate it through the urine, with the loss of water associated with frequent urination. But researchers have found that, in reality, this excess has the opposite effect in the medium and long term. To conserve the body’s water in the context of numerous visits to the bathroom, a lot of energy is needed, which the body obtains eating more. This explains why excess salt whets our appetite.
Jens Titze, professor of Medicine, Molecular Physiology and Biomedicine, and one of the main authors of the work, recalls that in an experiment with Russian astronauts, he and his colleagues found that when the daily amount of salt present in the cosmonauts’ diet increased six to twelve grams, they drank less water, and no more. This suggested that these men conserved more liquid element, or that they produced more.
In a later study with mice, the researchers found that too much salt led the rodents to produce more glucocorticoids, hormones that help break down muscle proteins and extract energy from them, something necessary when the body makes an extra effort to eliminate excess salt . Those proteins were converted into urea in the liver of animals, and urea helps the kidneys to prevent excessive loss of water when urinating.
Getting energy from muscles is much more risky and expensive than getting it from food, and that’s why the Russian astronauts were hungrier during the aforementioned experiment.
The vicious circle
In any case, a continuous excessive intake of salt creates a dangerous dynamic. To eliminate it, the body begins the process that we have described, and produces many glucocorticoids, hormones that participate in the regulation of carbohydrate metabolism and have a confirmed role in the development of ailments such as diabetes, obesity, osteoporosis and cardiovascular diseases .
In addition, too much salt whets the appetite, with harmful consequences for health. As Titze says, “we have always focused on the role this seasoning plays in the development of hypertension. But our findings indicate that a diet too rich in this substance can predispose to metabolic syndrome”, a series of conditions that elevate the risk of developing heart disease and type 2 diabetes.
