Many biologists believe that the saline content of our blood and tears closely resemble the salinity of the sea when our single cell ancestors existed. The sea has changed over millions of years and is much more saline than what it was, however, it still contains the salts that are required for life but in larger quantities. There are groups of people who believe that seawater can cure some illnesses, for example ‘Ocean Health’ , but until it appears in a medical journal I will take that information with a pinch of salt. Note that saline drips are common in hospitals.
Salt in the correct quantity is essential to life and many animals in the wild will seek out salt licks if their diet is salt deficient. Some hunters will put out artificial salt licks to attract game. Too little salt in the diet can lead to muscle cramps, dizziness, electrolyte disturbance, water intoxication or even death. Too much salt in the diet can lead to high blood pressure, stroke and heart disease, cardiac enlargement, fluid retention, stomach cancer and death. In Australia and New Zealand the recommended adequate intake for adults of salt per day is 1150mg–2300mg and the upper level is 5750mg. One study indicates that sodium intake is tightly controlled by feedback loops within the body, low salt levels create a hunger for salty food, and that attempts to reduce the intake below 2700mg per day may be futile.
Salt has been mined for thousands of years and the word for ‘salt’ in the various world languages has meanings beyond the obvious, for instance the words salary and salad were derived from salt. Salt has a religious significance in most cultures and is used in many ceremonies. I wonder if being sent to the salt mines is still a punishment.
When we say salt we normally think of purified salt which is mainly sodium chloride. In nature, salt may consist of a number of different salts. Seawater is different to pan salt which is different to rock salt and they differ depending on where they were extracted. The epicurean will have his or her favourite table salt produced from a specific region and will insist that no other will suffice. The rest of us have a choice between sea salt, rock salt, and purified salt. The up-market snack food providers seem to prefer sea salt, presumably this is the fashionable salt to use.
Many countries require salt to contain mineral additives to compensate for population mineral diet deficiencies. Australia has a deficiency of iodine in the soil and has legislated for all bread to be made with iodised salt. Iodised salt is also available as table salt and should be used whenever possible unless you consume large quantities of seaweed. You can find some iodine facts here. There are some people that think that the mineral additives are poisoning them and protest loudly.
Most companies that produce table salt use additives to allow easy pouring of salt. An incomplete list of anti-caking agents include tricalcium phosphate, calcium or magnesium carbonates, fatty acid salts, magnesium oxide, silicon dioxide, calcium silicate, sodium aluminosilicate, and calcium aluminosilicate. If you are a purest you can always buy salt in block form, powder enough salt for a salt cellar and add uncooked rice grains as a desiccant, or, you can use rock salt as large crystals or flakes and grind it over your food using a pepper grinder.
Salt substitutes are available and normally contain a mixture of potassium chloride and sodium chloride. WARNING: do not use a salt substitute without checking with your family doctor as it can be fatal for people suffering from heart, kidney or liver problems.
To use the forbidden ‘D’ word, the best way to avoid too much salt is to modify your Diet. When I was diagnosed with high blood pressure my wife decided to gradually reduce the salt in her cooking and remove the salt cellar from the dining table. After the initial shock wore off we started to taste the true flavour of many of the foods and could even distinguish the tastes of various types of potatoes, even chips (French fries) tasted good without extra salt. We don’t buy a lot of manufactured foods, mainly themed sauces, and dinner bases and in general we ignore the low salt versions, except for margarine, because they taste terrible. My blood tests show that my sodium is normal and I now enjoy the flavours of foods as Mother Nature intended.
"Moderation is a fatal thing. Nothing succeeds like excess."