So is soup too salty?

We all eat too much salt - and usually because we don't know we're doing it. While experts recommend that adults consume no more than 6g (a large teaspoonful) of salt a day, most of us manage to take in 10-12g - simply by eating pre-packaged food.

The consequences for the nation's health are severe. Eating too much salt can lead to an increase in blood pressure, which is linked to a higher incidence of heart disease and strokes - as well as to osteoporosis and stomach cancer.

Shockingly, 80 per cent of the average person's high salt intake comes not from obvious sources, such as crisps, but from processed foods - bread, breakfast cereals, ready-made meals and particularly, as the latest research from campaigning group CASH (Consensus Action on Salt and Health) reveals, from soups.

"Tinned soup tends to have a higher salt content than 'freshly made', preprepared soups, but if you eat any readymeals, you are consuming too much salt," says Ian Marber of the Food Doctor Nutrition Clinic. "Salt makes the body hold on to water, which increases blood pressure and water retention.

Interestingly, if you have too little zinc in your diet, your taste buds won't be as sensitive to salt as they should be. Try making your own soup, using saltfree stock cubes, and herbs, spices, black pepper and lemon juice for flavouring, and taste the difference."

Cash has suggested that a 3g reduction in the amount of salt we consume would lead to 22 per cent fewer strokes and a 16 per cent reduction in heart disease, saving 35,000 deaths a year. CASH's new research reveals the frightening amounts of salt contained in soup.

Confusingly, manufacturers refer to salt (sodium chloride) as "sodium" (the sodium in salt can lead to health problems). To convert a figure for sodium into the figure for salt content, you must multiply it by 2.4. It is easier to think in the following terms. Anything over 0.5g of sodium per 100g of food equates to a lot; while 0.1g of sodium is a little.

Small amounts of sodium - 1.6g per day, equivalent to 4g per day of salt - are needed by the body to transmit nerve impulses, help in muscle contractions, and maintain a healthy balance of fluid.

But the net result is simple. Something which looks healthy - a 600g pot of freshly made vegetable soup - may contain up to 6g salt, ie a heaped teaspoonful, and as much as you would find in six small packets of crisps. And that is before you add salt at the dinner table.

Manufacturers are aware of the problem - Sainsbury's is aiming to reduce salt to no more than 2.5g per helping.

"Try to consume no more than 6g of salt a day, that is roughly 2g of salt per meal," says Dr Sarah Schenker, nutrition scientist with the British Nutrition Foundation. "Choose a soup with no more than 2.5g of salt per helping."

This is how much salt you find in a large (300ml) bowl of the following soups: