Salt is known as the "mother of a hundred flavors." It is not only an indispensable condiment in daily diet but also a vital substance for maintaining normal human development. The main component of salt is sodium chloride, which is 39% sodium and 61% chloride. In the human body, salt can be broken down into sodium ions and chloride ions, each playing different roles.
Sodium ions help maintain the body's overall blood volume and cellular osmotic pressure, ensure the normal excitability and responsiveness of nerves and muscles, and activate various functions such as muscle contraction. Chloride ions, on the other hand, help regulate the body's acid-base balance, produce stomach acid, and activate amylase, all of which are crucial for life activities. Many people know that a high-salt diet is unhealthy and have one-sidedly believed that the less salt they eat, the better, and some even avoid salt altogether. This is actually a misconception.
As is well known, high salt can increase blood pressure, while low salt can lower it. People in northern regions consume more salt than those in the south, so their blood pressure is generally higher. Doctors often advise patients with hypertension to "not eat too salty" and to follow a lighter diet to help control blood pressure. In fact, not everyone who eats a lot of salt will develop hypertension. Studies have shown that about one-fifth of the population is sensitive to salt. When these people consume too much salt, they can develop hypertension; if they already have it, their blood pressure will rise further. American experts observed 1,900 hypertension patients for up to four years, periodically analyzing the salt content in their urine. They found that patients with the lowest urine salt content had a four times higher incidence of myocardial infarction than those with normal levels. Therefore, even for hypertension patients, it is not a case of the less salt the better. Currently, medicine cannot identify individuals who are sensitive to salt, so the World Health Organization recommends that daily salt intake should be controlled to around 5 grams.
A low-salt diet does not mean that the less salt you eat, the better, nor does it mean no salt at all. Excessive salt restriction can have certain side effects. Insufficient sodium salt intake can cause an imbalance in osmotic pressure inside and outside the body's cells, prompting water to enter the cells, which can lead to varying degrees of cerebral edema. Mild cases may cause disturbances in consciousness, including drowsiness, fatigue, and confusion, while severe cases can lead to coma. If salt intake is excessively restricted for a long time, it can lead to abnormally low serum sodium levels, causing neurological and psychiatric symptoms such as loss of appetite, limb weakness, and dizziness. In severe cases, symptoms like anorexia, nausea, vomiting, accelerated heart rate, weak pulse, muscle spasms, blurred vision, and diminished reflexes may occur, a condition medically known as "hyponatremia." A rapid reduction in salt can decrease body fluid volume and increase the activity of the renin-angiotensin system and the sympathetic nervous system, which can cause blood pressure to rise in some patients.
Medical practice tells us that a low-salt diet is very beneficial for patients with hypertension, but not everyone needs a low-salt diet. Whether a person needs a low-salt diet should depend on their own health status. Individuals with kidney diseases and chronic stomach problems should limit their salt intake, and it is advisable to eat less salt. Apart from that, for people with generally normal blood pressure, there is no need to deliberately restrict salt intake.