Salt, or chemically recognized as sodium chloride, is made up of 40% sodium and 60% chlorine. It serves as a spice, binder, and food stabilizer. It can also be used as a preservative because bacteria cannot survive in an environment with high salt concentrations.
The human body needs small amounts of sodium, which is important for transmitting nerve impulses, for contractions and relaxation of muscles, and for maintaining a proper balance of water and minerals.
It is estimated that each person needs 500 mg of sodium per day to maintain these vital functions. But too much sodium in your diet can cause problems such as high blood pressure, heart disease, and heart attack. It can also cause a loss of calcium, which is most often acquired from the bones, which leads to bone disease.
A research performed in the United States shows that the average American consumes at least 1.5 teaspoons of salt per day. Translated into milligrams of sodium intake, we are speaking of 3,400 mg, which is almost 7 times more than necessary.
The daily intake that is necessary to maintain vital functions, as mentioned, is 500 mg, which is easy achievable with today's diet. Intake of 500 mg of sodium, or just over 1 g of salt per day, while meeting the other needs of the body, such as energy and other essential nutrients, is virtually impossible, especially considering that the salt is not just a supplement and spice, but also a part of every food.
Hence, according to the World Health Organization, the optimal sodium intake is 2 g or about 4 g of salt per day. US health institutions recommend an even lower intake - 1.5 g of sodium. There is no consensus on this data because there is no solid evidence that would determine the toxic effects of sodium, but in chronic diseases, we have a different situation.
Sodium and health
In most people, the kidneys have trouble coping with excess sodium levels in the blood. As sodium stores, the body retains more water to dissolve it. This causes a condition in which we have an increase in the fluid that surrounds the cells and an increase in the volume of blood that flows in the blood vessels. An increase in blood volume means more work for the heart and thus increased blood pressure.
Over time, this increased heart rate can weaken blood vessels and the heart, leading to chronic hypertension or high blood pressure, and ultimately lead to heart attack and stroke.
There is evidence that excessive salt intake can damage the heart, aorta, and kidneys without increasing blood pressure. It also has a negative effect on the bones.
Elevated blood pressure has been shown to be a leading cause of cardiovascular diseases. We have previously shown a link between increased salt intake and high blood pressure. Hypertension is the leading reason for heart diseases and strokes, causing two-thirds of them. In China, for example, high blood pressure causes premature deaths of 1 million people a year.
It has been shown that different individuals react differently to the amount of salt or sodium ingested. Genetics is thought to be responsible for this. Those who are 'more sensitive' to salt have better results in lowering blood pressure after reducing salt in the diet. Those who are 'resistant' to salt and a diet rich in salt might not experience a significant decrease in blood pressure.
But while there is no consensus on the optimal daily salt intake for the reasons explained, summarized data from multiple studies suggest that there is a benefit to limiting salt intake for all individuals in general.
There are several important clinical trials showing the link between increased salt intake and cardiovascular disease:
"Intersalt" is a study of the relationship between salt intake and blood pressure. Researchers measured sodium excretion in 24 hours in 10,000 adults in 32 different countries. The average excretion rate was about 4 g of sodium per day. However, the range is wide, from 0.2 g in Brazil to 10.3 g in Japan.
Populations that consumed more salt had higher average blood pressure and increased blood pressure in older age. Subjects in countries where the salt was consumed in amounts of about 1.5 g per day, had lower average blood pressure and a slight increase in blood pressure in older age.
Thus, the researchers with this study have shown a direct link between increased blood pressure and increased salt intake.
"TOHP" - A series of studies on the prevention of hypertension that have been conducted from 1987 to 1995. They examined the impact of lifestyle changes on blood pressure, and the changes involved weight loss, stress management, the use of appropriate supplements as a supplement to diet and consumption of less salt.
Each study has shown a slight decrease in blood pressure, which followed a decrease in salt intake over 18-36 months. Years after the study, the researchers analyzed the same subjects again and found that:
- Those who had a reduced salt intake in the previous study had a 25% to 30% reduced risk of heart attack or stroke unlike those who continued the same salt intake as earlier.
"DASH" - Research on the role of diet in stopping hypertension that began in 1994. 459 subjects were subjected to a special diet that included limited intake of processed sugars, red meat, dairy products and other foods rich in saturated fats and larger amounts of fresh foods (fruits and vegetables), whole foods rich in cellulose fiber, minerals, and vitamins, legumes, etc. The same number of other respondents had a standard diet, high in processed sugars and saturated fats, and poorer in fresh and whole foods. After 8 weeks, it was estimated that the first group had decreased both systolic and diastolic blood pressure. The second study found that reducing salt intake, both in the first diet and in the standard diet, had a significant effect on reducing blood pressure.
The amount of calcium that the body loses through urination increases with increasing salt intake through the diet. If the calcium is in smaller amounts in the blood, then it is taken from the bones.
Thus, a high-salt diet can have an additional side effect - bone loss, a disease known as osteoporosis. A study of postmenopausal women found that hip density during two years was directly related to sodium excretion within 24 hours of the start of the study. Also, this had a direct relationship with blood calcium levels and intake.
Another study found that reduced salt intake led to a positive balance of calcium in the blood, which reduces the loss of calcium from the bones, which inevitably occurs in the aging process.
Some studies have linked increased salt intake to gastric cancer. The World Cancer Research Fund and the American Institute for the Study of Malignant Diseases also suggest that increased salt intake increases the risk of gastric cancer.
Chronic Kidney Disease
Elevated blood pressure is also a risk factor for these diseases. Although there is strong evidence that increased salt intake is associated with increased blood pressure, there is no evidence that reduced salt intake will protect us from chronic moderate kidney disease. A study of patients with diagnosed chronic kidney disease found that consuming more than 4.6 g of salt in these individuals reduced the progress of the disease.
On the other hand, reduced intake below 2.3 g has no significant effect when compared to the effect of moderate intake of about 3-4 g per day. That's why doctors recommend a moderate intake of sodium through salt to prevent these diseases.
Sources of salt in the food
We should not be concerned about not getting enough salt. Almost every processed food contains some amount of salt, and we add salt while cooking and eating.
Foods with the highest amount of salt include pizzas, sandwiches, canned meat products, soups, cheeses, omelets, various types of snacks (chips, crackers, etc.), and many others. Therefore, we should not be afraid of the lack of salt (hyponatremia) that sometimes occurs in the elder population in nursing homes or hospitals, where they receive therapies that in various ways remove sodium from the body.
On the other hand, salt poisoning (hypernatremia) is more common. When sodium accumulates in the blood, water is transferred out of the blood cells to dissolve the sodium. This effect on the blood can cause serious problems such as seizures, coma, and sometimes death. Accumulation of excess fluid in the lungs can cause shortness of breath, and other symptoms of hypernatremia include vomiting, nausea, confusion, kidney damage, loss of appetite, and so on.
The relationship between sodium and potassium
Sodium and potassium are closely linked but have opposite effects on the body. Both elements are essential for maintaining the body's physiological balance and are associated with the risk of chronic diseases, especially cardiovascular disease.
Increased salt intake causes an increase in blood pressure, leading to heart disease, while increased potassium intake can help relax blood vessels and excrete sodium, which leads to lower blood pressure. Our bodies have far greater daily needs for potassium than sodium. But most often, the standard diet provides just the opposite. The average potassium intake in the United States is 2.9 g per day, while the intake of sodium is 3.4 g.
A study published in the Archives of Internal Medicine found that people who had a high-sodium, low-potassium diet show a 20% higher risk of dying from a heart attack and other cardiovascular diseases.
How to reduce the risk of too much sodium and too little potassium?
Eating more fresh foods (fruits, vegetables ) that are naturally rich in potassium and low in sodium and reducing the intake of processed foods is a good prevention of the dangers posed by excessive sodium intake.
Are 'natural' salts healthier than regular table salt?
Salt is obtained as a mineral from salt mines or by evaporation of seawater. The term 'natural' is often misused, and so it is in this case. All types of salt are based on one chemical structure: sodium chloride. Although less processed salt contains more minerals, their amount is so small that it actually makes no difference. Different salts are mainly selected due to their slightly different taste.
Kitchen salt is usually iodinated with the aim of overcoming hypothyroidism (the lack of iodine that is necessary for the work of the thyroid gland). In order to keep this mineral: do not store salt in an open container, do not buy stocks of salt, and add the salt at the end of cooking. These are tips for preserving iodine in salt and are especially important.
Sea salt contains a higher percentage of other minerals than table salt, as it is less processed, but may also contain heavy metals found in the ocean. That's why manufacturers pay special attention to this part.
Himalayan (pink) salt is obtained from mines in Pakistan, contains small amounts of iron oxide, and also contains a larger amount of other minerals than table salt because it is less processed.Disclaimer: The purpose of this text is to stimulate critical health thinking. Medical information does not amount to advice and if advice is needed an appropriate professional help should be asked. No warranties or representations are given in respect of the medical information, and the website operator should not be held liable if a user suffers any injury or loss after relying upon the medical information.