Sodium: Facts and Myths

Reduction of Dietary Sodium and Sugars

Facts

Sodium and salt

The term "salt" and "sodium" is often used interchangeably.
Technically, table salt is a chemical compound known as sodium chloride (NaCl), which consists of 40% sodium and 60% chloride. In other words, for 1 gram of table salt, there is 0.4 gram (i.e. 400mg) of sodium.

Sources of sodium

Table salt is the main, but not the sole source of dietary sodium.
Besides table salt, sodium-containing condiments and sauces, such as monosodium glutamate (MSG), soya sauce, oyster sauce, bouillon cubes are key contributors of sodium in our diet.
Salt or other sodium-containing preservatives, e.g. sodium nitrate and sodium nitrite, are often added to canned food and processed food such as bacon and sausage.
Sodium may lurk in all kinds of unexpected foods in the form of food additives, like bread, biscuits and cereals that contain sodium carbonates as anticaking agent, acidity regulator or raising agent.
Sodium itself is also naturally found, although in small amount, in some food like milk, fish, vegetables and drinking water.

Sodium content in food

Ways to find out the sodium content in food include looking at nutrition label and searching sodium information in food composition databases, such as the Nutrient Information Inquiry System.

Sodium and Health

Sodium is essential for body functions. It helps to maintain the extra-cellular fluid balance and acid-base balance in the body. It is required for nerve transmission and muscle contraction.
Some individuals are more sensitive to sodium, meaning that they tend to retain sodium more easily and in turn may have higher risk of developing hypertension. Untreated high blood pressure can lead to heart attack, stroke, kidney failure, etc.
Besides hypertension, in recent years, expert reports from the World Health Organization (WHO) and the World Cancer Research Fund concluded that salt and salt-preserved foods probably increase the risk of stomach cancer.

Myths

Myth 1:	I am healthy and do not suffer from any non-communicable diseases, so I need not worry about my dietary sodium intake.
Fact 1:	High salt intake can raise blood pressure at any age, and high blood pressure is one of the significant risk factors of many non-communicable diseases including cardiovascular disease, stroke and coronary heart disease. According to WHO, a relative reduction in sodium intake resulted in lowered blood pressure in adults with or without hypertension and this produces a positive effect on health, as WHO indicates that even small reductions in blood pressure would reduce the risk of heart attack and stroke for those who are not diagnosed with high blood pressure. WHO recommends that the daily intake of sodium of an average adult should be less than 2000 mg of sodium (slightly less than 1 level teaspoon of salt which weighs 5.8g and contains 2300mg of sodium). It also recommends that the dietary intake of salt shall be reduced by a relative 30% as a target by 2025.
Myth 2:	Sea salt has lower sodium content by weight than table salt, and therefore is a healthier alternative.
Fact 2:	Sea salt is a type of table salt, which contains the same amount of sodium by weight. However, sea salt is often found in the shape of big crystals (coarse salt), in turn it is more loosely packed than table salt. Hence, a teaspoon of coarse sea salt may weigh less than a teaspoon of table salt and therefore, may contain less sodium.
Myth 3:	I need to take more salt after sweating to replenish the lost.
Fact 3:	Only minimal amount of salt is lost through sweat even in hot and humid climates, so no extra salt in the diet is necessary. If you really sweat a lot after intense physical activity under extreme hot weather and hence sodium losses in sweat are increased, most of us can replenish the necessary sodium by normal diet without extra salt intake in practice. What you actually need to do is to drink a lot of water to replenish the lost fluid.
Myth 4:	There is no sodium in sauces and condiments that do not taste salty.
Fact 4:	Not all sodium-rich foods taste salty because other ingredients such as sugar could mask the flavor of salt after mixing together. You can notice that many sauces and condiments we usually use contain high sugar content as well, therefore it is important to read nutrition label to identify sodium levels in different sauces and condiments.