By Enyeribe Ejiogu

The human body is designed with a self-regulating internal mechanism for maintaining balance in all its metabolic processes and the physiological functions of the various tissues, organs and systems.

Without the internal mechanism, the body, which is like a complex, intricately coordinated combination of machines, would breakdown. One little element that helps the body maintain internal balance is sodium, which it gets as sodium chloride (NaCl). 

Sodium is a crucial electrolyte in the body. Many foods naturally contain small amounts of sodium, but most of the sodium in the diet comes from salt. Salt is made of sodium (40 per cent by weight) and chloride (60 per cent by weight).

What sodium does in the body is to bind water and maintain intracellular and extracellular fluids in the right balance.

It is also an electrically charged molecule. It is the interplay between sodium and potassium that helps to maintain electrical gradients across cell membranes, which are vital and critical for transmission of electrical impulses through the nerves, facilitate muscular contraction, and various other functions.

In essence, it is impossible for the body to function without sodium. If the concentration of sodium in the bloodstream is high, the more water it binds. It is tendency to bind water that makes sodium increase the blood pressure (which it does, but only mildly).

If blood pressure is elevated, the heart has to work harder to push the blood throughout the body and there is increased strain on the arteries and various organs.

Therefore, high blood pressure otherwise called hypertension is a major risk factor for many serious diseases like heart disease, stroke and kidney failure.

It is for this reason that the World Health Organisation (WHO) and several medical experts strongly advise that individuals should drastically cut down consumption of popular salty foods. WHO recommends that adults should consume less than 2,000 mg of sodium, which is equivalent to 5 grams of salt per day.

Although doctors and nutritionists counsel on the health benefits of reducing salt consumption, to lower the risk of developing major adverse systemic conditions or worsen existing ones, it is necessary to bear in mind that blood pressure itself doesn’t kill anyone directly. It’s a risk factor, not necessarily a cause of disease as some experts argue that there is no benefit to sodium restriction when it comes to preventing heart disease or death. The reason is that too little sodium can cause downright harm.

Multiple studies show that salt restriction causes adverse effects on health. In a massive review, low sodium diets were found to cause an increase in LDL (the “bad” cholesterol) by 4.6 per cent and an increase in triglycerides by 5.9 per cent.

More findings showed that low salt caused increased insulin resistance. In one study, just 7 days on a low sodium diet increased insulin resistance, which is a leading cause of obesity, diabetes and metabolic syndrome.

In addition, a study found that in patients with type II diabetes, less sodium was associated with an increased risk of death.

Low salt intake, especially in athletes, can cause hyponatremia, a sodium deficiency, which can be very dangerous.

Other benefits of reducing salt intake

Because consuming too much sodium increases risk of cardiovascular diseases, health organizations generally recommend that people reduce their dietary intake of salt. High sodium intake is associated with a greater risk of stroke, total cardiovascular disease and kidney disease. A reduction in sodium intake by 1,000 mg per day may reduce cardiovascular disease by about 30 percent. In adults and children with no acute illness, a decrease in the intake of sodium from the typical high levels reduces blood pressure. A low sodium diet results in a greater improvement in blood pressure in people with hypertension.

Guidelines by the United States recommend that people with hypertension and middle-aged and older adults should limit consumption to no more than 1,500 mg of sodium per day and meet the potassium recommendation of 4,700 mg/day with a healthy diet of fruits and vegetables.

While reduction of sodium intake to less than 2,300 mg per day is recommended by developed countries, one review recommended that sodium intake be reduced to at least 1,200 mg (contained in 3 g of salt) per day, as a further reduction in salt intake the greater the fall in systolic blood pressure for all age groups and ethnicities.

Available forms of salt

Salt is used in many cuisines around the world, and it is often found in salt shakers on diners’ eating tables for their personal use on food. Salt is also an ingredient in many manufactured foodstuffs. Table salt is a refined salt containing about 97 to 99 percent sodium chloride. Usually, anticaking agents such as sodium aluminosilicate or magnesium carbonate are added to make it free flowing. Iodized salt, containing potassium iodide, is widely available.

Some table salt sold for consumption contain additives which address a variety of health concerns, especially in the developing world. The identities and amounts of additives vary widely from country to country. Iodine is an important micronutrient for humans, and a deficiency of the element can cause lowered production of thyroxine (hypothyroidism) and enlargement of the thyroid gland (endemic goitre) in adults or cretinism in children. Iodized salt has been used to correct these conditions since 1924 and consists of table salt mixed with a minute amount of potassium iodide, sodium iodide or sodium iodate. A small amount of dextrose may also be added to stabilize the iodine. Iodine deficiency affects about two billion people around the world and is the leading preventable cause of mental retardation. Iodized table salt has significantly reduced disorders of iodine deficiency in countries where it is used.

The amount of iodine and the specific iodine compound added to salt varies from country to country. In the United States, the Food and Drug Administration (FDA) recommends 150 micrograms of iodine per day for both men and women. US iodized salt contains 46–77 ppm (parts per million), whereas in the UK the iodine content of iodized salt is recommended to be 10–22 ppm.

Sodium ferrocyanide, also known as yellow prussiate of soda, is sometimes added to salt as an anticaking agent. The additive is considered safe for human consumption. Such anti-caking agents have been added since at least 1911 when magnesium carbonate was first added to salt to make it flow more freely. The safety of sodium ferrocyanide as a food additive was found to be provisionally acceptable by the Committee on Toxicity in 1988. Other anticaking agents sometimes used include tricalcium phosphate, calcium or magnesium carbonates, fatty acid salts (acid salts), magnesium oxide, silicon dioxide, calcium silicate, sodium aluminosilicate and calcium aluminosilicate. Both the European Union and the United States Food and Drug Administration permitted the use of aluminium in the latter two compounds.

In “doubly fortified salt”, both iodide and iron salts are added. The latter alleviates iron deficiency anaemia, which interferes with the mental development of an estimated 40 per cent of infants in the developing world. A typical iron source is ferrous fumarate. Another additive, especially important for pregnant women, is folic acid (vitamin B9), which gives the table salt a yellow color. Folic acid helps prevent neural tube defects and anaemia, which affect young mothers, especially in developing countries.

A lack of fluorine in the diet is the cause of a greatly increased incidence of dental caries. Fluoride salts can be added to table salt with the goal of reducing tooth decay, especially in countries that have not benefited from fluoridated toothpastes and fluoridated water. The practice is more common in some European countries where water fluoridation is not carried out. In France, 35 per cent of the table salt sold contains added sodium fluoride.

Salt in food

Salt is present in most foods, but in naturally occurring foodstuffs such as meats, vegetables and fruit, it is present in very small quantities. It is often added to processed foods (such as canned foods and especially salted foods, pickled foods, and snack foods or other convenience foods served as barbecue), where it functions as both a preservative and a flavoring. Dairy salt is used in the preparation of butter and cheese products. The main sources of salt in the diet, apart from direct use of sodium chloride, are bread and cereal products, meat products and milk and dairy products.

With material adapted from Wikipedia.com and healthline.com