Salt: Good or bad?

Posted by Master, Doctor Mai Vien Phuong - Gastrointestinal Endoscopy - Department of Examination & Internal Medicine - Vinmec Central Park International General Hospital

Health organizations have warned us about the dangers of salt, because eating too much salt can cause a number of health problems, including high blood pressure and heart disease. However, decades of research have failed to produce convincing evidence to support this. What's more, many studies actually show that eating too little salt can be harmful.

Salt is also known as sodium chloride (NaCl), consisting of 40% sodium and 60% chloride, by weight. Salt is by far the largest source of sodium in the diet, and the words "salt" and "sodium" are often used interchangeably.
Some salts may contain trace amounts of calcium, potassium, iron and zinc. Iodine is often added to table salt.
The essential minerals in salt act as important electrolytes in the body. They help with fluid balance, nerve transmission, and muscle function. Some amount of salt is found naturally in most foods and salt is also frequently added to foods to improve flavor.
Historically, salt was used to preserve food, preventing the growth of bacteria that prevent food from spoiling. Salt is harvested in two main ways: from salt mines and by evaporating seawater or other mineral-rich water.
There are actually many types of salt available. Popular varieties include table salt, pink Himalayan salt, and sea salt. Different salts can vary in taste, texture, and color. If you are wondering which salt is the healthiest, the truth is that they are all quite similar.

Health authorities have been asking us to cut back on sodium for decades. They say you should consume no more than 2,300 mg of sodium per day, preferably less. This is equivalent to about a teaspoon, or 6 grams of salt (it's 40% sodium, so multiply the grams of sodium by 2.5).
However, about 90% of adults in the US consume more than that. Eating too much salt is thought to raise blood pressure, thereby increasing the risk of heart disease and stroke.
In fact, there is some serious doubt about the real benefits of sodium restriction. It is true that reducing salt intake can lower blood pressure, especially in people with a condition called salt-sensitive hypertension. However, for healthy people, the average reduction is very small.
A study from 2013 found that, for people with normal blood pressure, limiting salt intake reduced systolic blood pressure by just 2.42 mmHg and diastolic blood pressure by just 1.00 mmHg. Furthermore, several review studies found no evidence that limiting salt intake reduces the risk of heart attack, stroke, or death.

Limiting salt intake will lower blood pressure a bit. However, there is no solid evidence linking reduced intake to a lower risk of heart attack, stroke or death.

There is some evidence that a low-salt diet can be completely harmful. Negative health effects include:
Increased LDL cholesterol and triglycerides: Salt restriction has been linked to increased LDL ("bad") cholesterol and triglycerides. Heart disease: Some studies report that less than 3,000 mg of sodium per day is associated with an increased risk of dying from heart disease. Heart failure: One analysis found that limiting salt intake increased the risk of death in people with heart failure. The effect was staggering, with a 160% higher risk of death in those who reduced their salt intake. Insulin resistance: Some studies have reported that a low-salt diet can increase insulin resistance. Type 2 diabetes: One study found that in patients with type 2 diabetes, less sodium was associated with an increased risk of death. Low-salt diets are associated with higher LDL and triglyceride levels, and increased insulin resistance. It can increase your risk of dying from heart disease, heart failure, and type 2 diabetes.

Stomach cancer is the 5th most common cancer among cancers. It is the third leading cause of cancer death worldwide and responsible for more than 700,000 deaths each year.
Some observational studies link a high-salt diet to an increased risk of stomach cancer. A large review paper from 2012 looked at data from 7 prospective studies, including a total of 268,718 participants.
The results showed that people who eat a lot of salt have a 68% higher risk of stomach cancer than those who eat less. Exactly how or why this happens is not well understood, but several theories exist:
Bacterial growth: Eating a lot of salt can increase the growth of Helicobacter pylori a type of bacteria. Bacteria can lead to stomach ulcers. This can increase the risk of stomach cancer. Damage to the stomach lining: A diet high in salt can damage and inflame the stomach lining, thereby exposing the stomach lining to carcinogens.

However, these are observational studies. They cannot prove that eating too much salt causes stomach cancer, only the two are closely related. Several observational studies have linked high salt intake to an increased risk of stomach cancer. This can be caused by a number of factors.

Most of the salt in the modern diet comes from restaurant foods or processed, packaged foods.
In fact, it is estimated that about 75% of the salt in the American diet comes from processed foods. Only 25% of the absorbed amount occurs naturally in foods or is added during cooking or at the table.
Salted snack foods, canned and ready-to-eat soups, processed meats, pickled foods and soy sauce are examples of foods high in salt. There are also some foods that don't appear to be salty but actually contain surprisingly high amounts of salt, including breads, cheeses, and some breakfast cereals.

Certain health conditions make you need to cut back on salt. However, if you're a healthy person who mainly eats whole, single-ingredient foods, you probably don't need to worry about your salt intake.
In this case, you can feel free to add salt while cooking or at the table to improve the taste. Eating too much salt can be harmful, but eating too little is also bad for your health. As is often the case in nutrition, optimal intake lies between the two extremes.
Therefore, to have good health, limit the risk of cardiovascular diseases, high blood pressure, we should maintain a moderate diet. If necessary, you can consult a nutritionist or doctor for in-depth advice.