The truth about salt

    Dr Ben Kelly, Head of Preventative Medicine at Nuffield Health, explains why some salt is necessary in our diets and how we can can take control of our daily intake

    Just as sugar has been demonised in the media over the years, salt has frequently been linked to high blood pressure and an increased risk of stroke and heart problems. However, while excess amounts of salt may cause long-term health problems, we all need some salt in our diet for the body to function properly – to help regulate fluids and carry electrical charges between cells. The latest research has even found that eating too little salt could be just as harmful, with a recent study by McMaster University and Hamilton Health Sciences finding that a low-sodium diet can in fact increase the risk of cardiovascular disease.

    With current guidelines suggesting we eat no more than 1 tsp of salt per day, the expert view is that we should adopt an ‘everything in moderation’ approach when it comes to salt in our diets. We ask Dr Ben Kelly from Nuffield Health for his expert advice on how salt can help the body function, the difference between ‘good’ and ‘bad’ salt, and how to cut down if we think we’re eating too much.

    Why do we need salt?

    There are several vital reasons the body needs salt to function properly:

    1. Fluid balance – sodium (found in salt) is an electrolyte that helps regulate the amount of water and the electrical activity in our cells. That’s why having too much salt can cause fluid retention and increase blood pressure.
    2. Energy regulation – sodium and potassium aid the movement of glucose in and out of cells, giving us energy.
    3. Nerve function – when a nerve cell fires off a signal, sodium enables the signal to reach its intended destination rapidly.
    4. Digestion – consuming salt activates an enzyme in your mouth that helps break down food. It’s also critical for the production of acid in the stomach that helps us to digest our food.

    If there isn’t enough sodium in our system, we can develop a condition known as hyponatremia – when the level in our blood is abnormally low. Symptoms include headaches, nausea, muscle cramps, lethargy, restlessness, disorientation and depressed reflexes.

    What’s the difference between sodium and salt?

    Salt is composed of two minerals: sodium and chloride (it also contains small amounts of calcium and phosphates). Table salt, for example, contains about 40% sodium and 60% chloride.

    Are certain types of salt better for me than others?

    While there may be differences in taste and texture, there are also differences in mineral and sodium content when it comes to table, sea or Himalayan pink salt.

    • Standard table salt is almost pure sodium chloride (or 97% and above).
    • Sea salt is almost entirely sodium chloride, but it is harvested from evaporated seawater and often contains other beneficial minerals such as potassium, iron and zinc.
    • Himalayan pink salt is mined in Pakistan, with the colour coming from iron oxide. It often has a lower total sodium content compared to table salt and contains small amounts of calcium, iron, potassium and magnesium.

    No single salt can be described as ‘healthier’ than another. No matter which salt you choose, it’s best to follow the RDA guidance.

    What’s the recommended amount of salt for men, women and children?

    The daily recommended maximum amount of salt we should eat depends on age:

    • 1 to 3 years: 2g salt per day (less than ½ tsp)
    • 4 to 6 years: 3g salt per day (approx. ½ tsp)
    • 7 to 10 years: 5g salt per day (approx. 1 tsp)
    • 11 years and over: 5-6g salt per day (approx. 1 tsp)

    What does consuming too much salt do to the body?

    There have been studies which associate excess sodium with coronary heart disease and stroke, but there is still research to be done on this. High salt intake can also have detrimental effects on smooth muscle within the lungs, which can particularly affect asthma sufferers, and it’s been linked to reduced bone density and stomach cancer.

    How do I know if I’m having too much salt?

    The side effects of having too much salt could include: thirst, headaches, swelling, increases in blood pressure, flushing (feeling suddenly hot).

    Which foods are highest in salt?

    Salt is naturally present at low levels in all foods, but around 70-80% of our salt intake is hidden in processed foods such as bacon, burgers, sausages, noodle snack pots, cheese, soy sauce, Marmite and stock cubes. There are also a number of foods that have surprisingly high levels of salt content (or salt blind spots) such as cereals, bread, ketchup, tinned veg and soups and salad dressings. Check the packaging before you buy and where possible opt for a reduced-salt and low-sodium alternative.

    What are your tips for controlling my salt intake?

    • Eat less processed foods. Try where possible to cook your own meals from scratch.
    • If you do still want to add salt, opt for the low or reduced sodium options.
    • Take notice of food labels. Anything with 1.5g salt or more per 100g is high in salt. Low salt options tend to have 0.3g salt or less per 100g.
    • If you’re eating out, request for the chef to hold back on the salt or ask which of the dishes have the lowest salt content.

    If you think you’re eating too much salt, try reducing additional salt content such as seasonings and table salt. Always consult your GP or healthcare professional before making any drastic change to your diet.

    Want to learn about the effects of sugar on the body? Read our guide here.

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