What is salt and how does it affect our blood pressure?

Since ancient times, salt has been used for taste and to preserve foods. However, too much salt can increase blood pressure, resultin in heart attacks and strokes. In this article we describe how too much salt increases blood pressure.  What is salt?

Salt is the common name for sodium chloride and the chemical formula is NaCl. It consists of 40% sodium and 60% chloride. In other words, 2.5 grams of salt contains 1 gram of sodium and 1.5 grams of chloride.

Why do we need salt?

Many body functions depend on sodium and chloride. Blood pressure is regulated, fluid balance is maintained, muscle and nerve function is maintained, and nutrients are absorbed and transported across the cell membrane. We digest food with the help of stomach acid (hydrochloric acid, HCl) produced by chlorine.

How much salt do we need per day?

The minimum daily requirement for salt is unknown, but it is estimated to be between 1.25 g and 2.5 g (0.5 g - 1 g sodium) per day. Because salt is found in a wide variety of foods, there is little risk of deficiency. According to the European Food Safety Authority (EFSA), a daily sodium intake of 5 g (equivalent to 2 g sodium) is sufficient to meet our sodium and chloride requirements as well as reduce our risk of high blood pressure and heart disease. All in all, this amounts to around 1 teaspoon of salt per day.

We release sodium and chloride from our bodies through urine and sweat. Our salt requirements may increase slightly during periods of heavy sweating, such as during exercise. Most people consume much more salt than required during these conditions, so it is usually not necessary to increase salt intake. 

How much salt do people eat in Europe?

Europeans consume between 8 and 12 grams of salt per day on average. In most European countries, both men and women consume well above recommended levels. Salt consumption is often higher among men than among women due to the fact that they tend to consume more food overall.

How does salt increase our blood pressure?

Normally our kidneys do a good job at regulating the sodium and water levels of our blood. Too much salt, however, can disturb this balance, causing sodium levels to rise in the blood. By holding onto more water, our body increases the volume of fluid surrounding our cells and the volume of blood in our bloodstream. As blood volume increases, the pressure on our blood vessels begins to increase and our heart needs to work harder to move blood around our body. Over time this extra strain can lead to stiffening of blood vessels and increases the risk of high blood pressure, heart disease and stroke.

Does reducing salt improve our blood pressure?

Several studies have shown that moderate reductions in salt intake (i.e. a reduction of 3 to 5 g or 12 to 1 teaspoon a day) can lower blood pressure. Individuals may see different effects depending on their starting blood pressure (those with higher blood pressure may see more benefits), their current level of salt intake, their genetics, their disease status, and their medication regimen.

It is important to note that salt is not the only lifestyle factor that can influence our blood pressure. Blood pressure can also be reduced by eating enough potassium, maintaining a healthy weight, not smoking, and being physically active. 

5 tips to reduce salt intake

The majority of salt we consume comes from ready-to-eat convenience foods and foods prepared outside the home. You can reduce your salt intake by following these tips:

1. Avoid adding salt to foods or use reduced-sodium table salts.
2. Salt can be found in even foods that don't taste salty, such as breakfast cereals or bread. It is always a good idea to check the nutritional information and select low salt varieties if possible
3. Rather than eating salted nuts, seeds, and other snacks, choose unsalted ones.
4.   Spices and herbs can be used to flavor food instead of salt.
5. Be conscious of foods eaten outside of the home and ask for less salt where possible.

High salt foods:

• Products such as bacon, salami, sausages, and ham that have been processed
• Cheeses
• Granules of gravy, stock cubes, and yeast extracts
• Pickles, olives, and other pickled foods
• Nuts and crisps that have been salted and dry-roasted
• Smoked and salted meats and fish
• There are a variety of sauces available, including soy sauce, ketchup, mayonnaise, and BBQ sauce