Also called sodium chloride, salt is a crystalline compound that consists of 40 percent sodium and 60 percent chloride. Some varieties may also contain trace amounts of calcium, potassium, iron and zinc. In its natural form, it is known as rock salt.
Salt is a substance essential for life – so essential, in fact, it has been the cause of numerous wars and conflicts over the centuries. In some countries it is even used in religious ceremonies.
Where does it come from?
There are two main sources of salt. The first is salt mines from which it is excavated – the Khewra salt mine in Pakistan for example. This is one of the largest salt mines in the world and is where pink himalayan salt comes from.
The other main source is the sea which contains vast quantities – no less than 3.5 percent of seawater is salt. It is separated from the water by the simple technique of evaporation.
Less important sources are mineral-rich waters found in shallow pools inland. It is also present in most natural foods, such as fruit and vegetables, albeit in very small quantities.
Regardless of where it comes from, however, all salt is very similar in taste, color (with the exception of pink himalayan salt), structure and nutrient content.
What is it used for?
A common use for salt is as a seasoning. There can’t be many households around the world that don’t have a salt cellar on the dinner table. In this capacity it ranks alongside sugar as one of the most common food flavorings. However, many people will be surprised to learn that of the some 200 million tons of salt that is produced every year, only 7 percent or so is eaten by us.
The rest is used in industrial processes, such as the production of plastics, paper, leather and a whole host of other products. Salt is used in the manufacture of butter and cheese. Prior to the advent of refrigeration, salting was one of the main methods of preserving foods. In this function, it works by preventing the growth of bacteria that cause food to go bad. Large quantities are required for this to be effective though – hence foods such as herring (also known as kippers in the UK) having such a high salt content.
Just as it does with sugar, the processed food industry also uses enormous quantities of salt, adding it to canned foods, meats such as bacon and fish, pickled foods, snack foods such as potato chips, sauces, bread, and breakfast cereals to name just a few. In fact, it is estimated that some 75 percent of the salt in the western diet comes from processed food. Only 25 percent occurs naturally in foods, or is added during cooking or at the table.
Salt and our health
Salt is an essential part of the human diet. Our bodies use it to maintain fluid levels, prevent low blood pressure, and regulate body functions such as heart rate, digestion and respiration. Salt also affects brain activity and lack of it can make people feel sluggish and lethargic. They may also experience seizures, loss of consciousness, comas and, ultimately, death. If salt levels fall quickly, all this can happen very rapidly.
Adult humans need about 6 grams (1 teaspoon) of salt a day to remain healthy. If we eat more than this on a regular basis however, problems such as osteoporosis, kidney disease and high blood pressure begin to appear. If left untreated, the latter can lead to cardiovascular disease and stroke.
The reason for this is that an excess of salt increases the amount of water in the blood and, as a consequence, the heart has to work harder to pump it around the body. In time, this can stretch the walls of the blood vessels making them more susceptible to damage. High blood pressure also contributes to the buildup of plaque in the arteries, leading to a greater risk of stroke and heart disease, amongst other problems.
Of the two – too much salt or too little salt, the former is by far the most common in the western diet. It is thought that, currently, we are eating 50 percent more than we should be. Very few of us eat too little salt actually.
For people who are eating too much, the easiest way to address the problem is to simply cut down on the amount of processed food they consume. This means restaurant meals, burger bars, takeaways, packaged snacks, etc, should all be taboo or just occasional.