Salt (also known as common salt or table salt) is a mineral composed of sodium chloride (NaCl). It is present in seawater (approx. 35g per one litre) from which it’s extracted through evaporation. It can also be processed from salt mines.
Salt is essential for animal and human life and its amount affects health. Too low level of sodium in blood may cause weakness, fatigue and muscle cramps or even spasms. Too high blood sodium can raise blood pressure and increase the risk of heart attack or stroke.
Salt has been known for thousands of years both as food seasoning and a method of food preservation. Nowadays, it is heavily added to most processed foods such as canned, pickled and snack foods.
The difference between salt and sodium
There are two common names present in the topic of salt – salt that we sprinkle over our food and sodium that is listed in the ingredients list of most products. If we want to control the intake amount, it’s essential to understand the relation between salt and sodium.
As mentioned before. common or table salt is a sodium chloride. It is a chemical compound present in nature. Its molecule consists of one atom of sodium and one atom of chlorine. Since chlorine atom is bigger and heavier it constitutes of 60% of sodium chloride mass. Sodium is just 40% by weight of salt. Therefore, when we refer to salt we mean the whole compound. Bear in mind that it is only sodium that affects our health and it is sodium that is listed in food ingredients list.
If you use a pinch of salt (approx. 1 gram) for your fried eggs, it will be just 400 mg of sodium (40% by weight of the mass of salt).
How much salt do we need?
According to WHO 2013 recommendation, adults should consume less than 2000 mg of sodium or 5 grams of salt per day. However, majority of people who eat a lot of processed or ready made food would consume even two times more than WHO recommendation.
How to know how much we eat? The table below helps to convert the amount of salt we add to our meals into the amount of sodium.
| Amount of salt | Grams of salt | Grams of sodium |
|---|---|---|
| a pinch | 1 | 0.4 (400 mg) |
| ¼ of a teaspoon | 1.25 | 0.5 (500 mg) |
| 1/3 of a teaspoon | 2.3 | 0.92 (920 mg) |
| Half a teaspoon | 2.5 | 1 (1000 mg) |
| ¾ of a teaspoon | 4 | 1.6 (1600 mg) |
| 1 teaspoon | 5 | 2 (2000 mg) |
| 1 ¼ teaspoon | 6 | 2.4 (2400 mg) |
| 2 teaspoons | 10 | 4 (4000 mg) |
| 2 ½ teaspoons | 12 | 4.8 (4800 mg) |
Apart from table salt that we use in our cooking we also eat salt added to processed and canned, smoked or baked products, which most of us love to indulge in. It’s so-called “hidden” salt and it’s present even in sweet products such as biscuits, cookies and cereals. The ingredients list should always include salt if it’s added. While nutrition facts will usually give back the mass of sodium present in food without distinguishing whether it originates from added salt or if it naturally occurs in food.
Below you will find an easy way to calculate it into mass of salt.
How to convert sodium to salt or salt to sodium
Sodium to salt
The amount of sodium in ingredients list has to be multiplied by 2.5 to indicate the amount of salt.
Salt to sodium
The amount of salt you use has to be divided by 2.5 to indicate the amount of sodium.
In the picture below you can see the ingredients list of tomato paste. In this case the ingredients list shows that only tomatoes were used to manufacture the paste. Nutrition facts reveal that two tablespoons (which is approx. 30 grams) will have 18 mg of sodium.
According to the calculation above it will be 45 mg of salt (the amount of sodium multiplied by 2.5, so 18 mg x 2.5 equals 45 mg).
Is it much?
One pinch of salt weighs 400 mg so the amount of salt in this case will be just a tenth of a pinch. It’s not much as for processed food but we need to bear in mind that the salt from all products we consume adds up to our daily intake.
What does “low sodium” mean?
The sodium content may originate from added salt or can be present in a product naturally. The products that will have “no added salt” or low sodium level can be considered suitable for low sodium diet.
Below you will find different quantities of sodium/salt that correspond to levels of sodium/salt:
- Low level of sodium/salt – 120mg sodium/0.3g salt or less per 100g of food
- Medium level of sodium/salt – between 120mg sodium/0.3g salt and 600mg sodium/1.5g salt per 100g of food
- High level of sodium/salt – 600mg sodium/1.5g salt or more per 100g of food.
Consequently, people on low sodium diet should eat plenty of products with low level of sodium/salt, small amount of medium level and avoid high-level products completely.
Other sources of sodium apart from table salt
Apart from table salt, there are other chemical compounds used as food additives and leavening agents that consist of sodium. These are:
- Baking soda and baking powder (sodium bicarbonate)
- Flavour enhancer monosodium glutamate (MSG)
- Food preservatives such as sodium benzoate, sodium nitrite or sodium sulfite
- Sodium ascorbate (which is antioxidant used in wines).
Food with highest levels of sodium
Not surprisingly this category will be filled in with all kinds of salty snacks such as crisps, crackers and pretzels. Remember that readymade meals, various types of sauces, cheese and even so-called healthy cereals may also contain plenty of salt.
The champions here are:
| Product | Serving size | Amount of sodium in milligrams | Amount of salt in milligrams |
|---|---|---|---|
| Barbecue sauce, Walden Farms, Original Barbeque Sauce | 2 Tbsp (30g) | 210 | 525 |
| Soy sauce, Kikkoman Organic Soya Sauce | 1 Tbsp (15ml) | 1020 | 2550 |
| Kellogg’s corn flakes | 1 cup (30g) | 204 | 500 |
| Croissant | One piece (57g) | 424 | 1060 |
| Masterfoods tomato sauce | 1 Tbsp (20ml) | 148 | 370 |
| Bagel | One piece (80g) | 460 | 1150 |
| Cottage cheese | 1 cup (125g) | 800 | 2000 |
Sources:
http://www.who.int/mediacentre/news/notes/2013/salt_potassium_20130131/en/