Lifeblood or poison – how much salt is good for you?

In Europe, people eat an average of 8 to 19 grammes of salt a day. Too much, says the WHO, recommending a maximum daily intake of 5 grammes for adults and 2 grammes for children.

Why your body needs sodium

Without sodium, a lot of things would go wrong in your body. The mineral helps regulate blood pressure as well as the acid-base and water balance, among other things. Together with potassium, it performs countless sodium-potassium pumps to import and export chemical substances between cells and regulates the water balance and therefore also blood pressure. Find out more on potassium here:

Sodium also serves as a buffer substance by helping to keep the pH value of blood within a narrow range. If it’s out of balance, this affects many biochemical processes in the body.

The mineral’s also indispensable for conducting stimuli in the nerves and muscles, as sodium ions enable the transmission of nerve impulses and the contraction of muscle fibres. In other words, a balanced sodium level’s essential to coordinate movements and for vital organs such as the heart to function properly.

What happens if there’s sodium deficiency or excess?

A lack of sodium in the body can cause tiredness, dizziness, muscle cramps and, in extreme cases, even unconsciousness. However, a severe deficiency is rare, as most people nowadays obtain more than enough salt through their diet.

Sodium excess is much more common. An overly salty diet increases blood pressure and the risk of cardiovascular disease. A high sodium intake puts a strain on the body by increasing blood volume. The resulting higher resistance in the blood vessels increases blood pressure. If this is too high in the long term, it damages the blood vessels and the heart and promotes heart attacks and strokes.

However, too much salt doesn’t have the same effects on everyone. Studies conducted in the field of nutrigenomics demonstrate that people react differently to a high sodium intake. It’s been shown that different variations of a certain gene influence whether people are particularly sensitive to salt. People with this sensitive gene variant experience a stronger increase in blood pressure, and particularly benefit from a low-sodium diet.

But remember, excess sodium can also damage the blood vessel walls and contribute to arteriosclerosis. A high intake of sodium chloride is also associated with an increased risk of stomach cancer, as it can damage the stomach lining. Too much salt also causes long-term problems for the kidneys.

Which foods are high in sodium?

Ready meals, snacks and fast food often contain hidden salt. But even seemingly harmless products including bread, muesli or sauces can contain a lot of sodium. It’s worth reading the nutritional information on processed foods and preferably going for low-salt alternatives instead. Unprocessed foods, especially fresh fruit, vegetables, pulses and wholegrain products naturally contain less sodium. So these can be eaten liberally.

What else you need to know about sodium

Sodium’s an extremely reactive alkali metal with surprising properties. Although it’s a metal, it floats on water. This is due to its very low density of just 0.97 g per cubic centimetre, which is lower than that of water. But don’t try this at home. If you throw a lump of sodium into water, it can explode. This is because sodium hydroxide is formed and hydrogen gas released. The reaction is so exothermic that the hydrogen gas can ignite.

And then there’s another fun fact: despite its metallic character, it’s so soft at room temperature that you can cut it with a knife. It’s even softer than lead.