Salt - healthy or unhealthy?

November 19, 2022

What is salt? What functions of our body do we need it for? What happens to us if we have too much or too little salt in our body?

The quick answer is - both healthy and unhealthy.

It all depends on how much salt we take in every day. More precisely, how much sodium we take in, because what we colloquially call salt is sodium chloride (NaCl), a substance consisting of about 40% sodium and 60% chloride.

There are claims that excessive salt intake causes high blood pressure and heart disease. However, the results of decades of research are quite contradictory.

World Health Organization (WHO) believes that approximately 2.5 million deaths could be prevented each year if salt intake could be reduced to recommended levels.

But.

There are several studies that show that insufficient salt intake is also harmful to our health and recommend consuming significantly more salt in the diet than recommended by the WHO.

But about everything in turn.

What is salt and why do we need it?

Salt is mainly composed of sodium and chloride and is the most important source of sodium in our diet.

Sodium is essential for our body's functions such as fluid balance, nerve health, nutrient absorption and muscle function, which allow us to move, talk and eat, control heart rate, breathing and digestion.

Some varieties of salt are fortified with iodine, iron and folic acid or combinations thereof, for example table salt often contains added iodine.

Sodium is also a part of many food products, even those that do not taste salty or even too sweet, for example - bread, meat, sauces, soups, etc.

A high concentration of salt helps prevent the growth of bacteria that cause food spoilage - so salt is often used as a preservative.

Salt can vary in taste, texture and color. The most popular types of salt are:

Today, the terms "salt" and "sodium" are often used as synonyms, which is probably one of the reasons why the salt consumption recommended in different sources is significantly different.

What happens when we eat too much salt?

Our body removes toxins and excess water from the body by filtering the blood through the kidneys, and a balance of sodium and potassium is necessary for this process to work properly.

If too much sodium (salt) is consumed in the diet, this balance of sodium and potassium is disturbed, causing a decrease in kidney function.

That is, too much sodium causes water retention (to dilute the sodium). As a result, both the amount of fluid in the cells and the total volume of blood in our bloodstream increases.

1 g of excess salt in our body retains around 100 g of water!

Over time, excessive salt intake can lead to high blood pressure (hypertension) resulting:

Blood vessels narrow and their flexibility decreases - the flow of blood and oxygen to the main organs decreases;
In order to provide the whole organism with what it needs (mainly oxygen), the heart pumps blood more and more forcefully - thereby increasing the blood pressure even more.

High blood pressure, especially over a long period of time, can:

Weaken the heart muscle (heart failure), because the heart's workload increases significantly;
Damage the walls of the arteries, which in turn can become the cause of a heart attack or stroke.

There is also some evidence that too much salt can damage the bones, heart, aorta and kidneys without raising blood pressure.

In summary, an increased amount of salt in the body can:

Raise blood pressure;
Increase the risk of cardiovascular diseases;
Increase the risk of kidney diseases;
Increase the risk of stomach cancer;
Raise dementia risk;
Increase the risk of osteoporosis;
Promote weight gain (changes in fat metabolism and water retention).

What happens if we eat too little salt?

Too much salt consumption is harmful, but too little salt can also cause health problems.

If the level of sodium in our body is too low, we can face problems such as:

Low blood pressure or hypotension. Some symptoms of low blood pressure are - dizziness, nausea, fainting, blurred vision, depression and dehydration;
Dehydration. Sodium plays an important role in maintaining fluid balance, so a decrease in sodium can lead to a condition where the body does not have enough fluid and is no longer able to function as it should. The most common signs of dehydration are headache, fatigue, dry mouth, and thirst.
Low sodium in the blood. Low-salt diets can cause hyponatremia. Hyponatremia is very dangerous for many of our organs, but especially for the brain. People with hyponatremia can develop serious neurological problems, such as mental disturbances, seizures, in severe cases even coma and death. Some people with hyponatremia also experience gastrointestinal disturbances, such as loss of appetite, vomiting, and nausea.
Increased cholesterol and triglyceride levels. Limiting salt in the diet is associated with increased levels of LDL (bad) cholesterol and triglycerides in the blood, which, in turn, increases the risk of heart disease.
Increased insulin resistance. Research results are contradictory, for example - in one study it is found that a low sodium diet increases insulin resistance after just 7 days, but in another no increase in insulin resistance is detected at all.

Salt sensitivity

Salt affects people differently. That is, the same amount of salt can significantly increase blood pressure for someone, but not at all for another.

People with high blood pressure, diabetes, and chronic kidney disease, as well as older adults, tend to be more sensitive to the blood pressure-raising effects of sodium.

And the question arises - how much salt is too little and how much is too much?

Official Dietary Guidelines

For decades, health authorities have encouraged people to limit sodium intake to control blood pressure.

However, the recommendations are quite different:

US Institute of Medicine (IOM) recommend for healthy adults intake of 1,500 mg (1.5 grams) of sodium per day;
US Department of Agriculture (USDA) and the US Department of Health and Human Services (HHS) recommend for healthy adults intake of up to 2,300 mg (2.3 grams) of sodium per day;
WHO recommends consume 2,000 mg (2 grams) of sodium per day;
The American Heart Association recommends take 1500 mg (1.5 grams) per day.

these guidelines do not apply to highly active people such as athletes or workers who are exposed to heat (due to increased sodium loss through sweating).

At the same time, there are studies which does not support current recommendations for general sodium restriction in the diet.

Some evidence suggests that reducing sodium intake below recommended levels may be harmful.

For instance, study, involving more than 133,000 people (both with high and normal blood pressure) from 49 countries on six continents, found that:

Regardless of blood pressure, people who got less than 3,000 mg (3 grams) of sodium per day were more likely to develop heart disease or die than people who got 4,000 to 5,000 mg (4 to 5 grams) of sodium per day.
In addition, those who took in less than 3,000 mg (3 grams) of sodium per day had worse health outcomes than people who took in 7,000 mg (7 grams).
People with high blood pressure who consumed more than 7 grams of sodium per day had a significantly higher risk of heart disease or death than people who consumed 4-5 grams per day.

These and other studies show that too little sodium can be harmful to human health, perhaps even more so than too much sodium.

Should salt intake be limited?

People with high blood pressure who consume more than 7 grams of sodium per day should definitely limit their salt intake.

However, reducing sodium in the diet does not seem to have much effect on healthy people.

And while health authorities continue to encourage sodium reduction, several studies show that reducing sodium intake to less than 3 grams per day can have negative health effects and raise concerns – or the current sodium intake guidelines (between 1.5g and 2.3g per day ) does not do more harm than good because there is increasing evidence that this level may be too low.

That is, if you consume more than 7 grams of sodium per day and you have high blood pressure, you should probably limit your sodium intake. But if you're healthy and feeling well, the amount of salt you're currently consuming is probably safe.

Is natural salt healthier than table salt?

So what makes table salt different from other types of salt?

Classic table salt is almost pure sodium chloride, but natural, for example, Himalayan pink salt contains various impurities - potassium, magnesium, calcium, etc.

When we talk about the health effects of salt, we are really talking about the health effects of sodium, and both table salt and natural salt contain sodium.

Therefore, the impact on health is also the same.

Key takeaways

Sodium is essential for our body - therefore limiting salt consumption is not always necessary.

As usual, it is important not to reduce or increase salt consumption, but to maintain an optimal sodium balance in the body.

Exactly how much sodium is needed for optimal provision of all body functions is not clearly known.

But,

It is clear that:

Too much sodium increases blood pressure and thus also the risks of cardiovascular diseases - therefore, if you have been diagnosed with high blood pressure or any cardiovascular disease, consult your doctor about the optimal amount of salt in your diet;
Too much sodium can cause chronic kidney disease (CKD ) and the formation of kidney stones;
Too little sodium can also cause even very serious health problems - so if you have low blood pressure, low blood sodium or high cholesterol, you may be consuming too little salt in your diet;
Salt in our body retains water, which often manifests itself as edema. In such cases, excess sodium can be reduced by drinking more water. You can read more about it HERE.

In addition to reading:

Blood, Sweat, and Tears – Salt in Medical history

Sources:

About Sodium

Your Kidneys & How They Work

Effect of lower sodium intake on health

Premature deaths attributable to blood pressure in China

Effect of longer term modest salt reduction on blood pressure

Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP)

A clinical trial of the effects of dietary patterns on blood pressure

A longitudinal study of the effect of sodium and calcium intakes on regional bone density in postmenopausal women

24-Hour Urinary Sodium and Potassium Excretion and Cardiovascular Risk