FOCUS: FOOD SCARE: Salt - the new drug

Try a breakfast-time experiment. As you pour out your cereal or munch your toast, check the packets for the item marked "sodium". This tells you how salty your food is in grams per 100 grams. For comparison, the sea contains 1g per 100g.

Cornflakes? 1.1g, or 10 per cent saltier than seawater. Bread? Usually about 0.5g - half as salty as the sea. And perhaps you're having Vitalite ("cholesterol-free") margarine with your toast - 0.8g. If you're eating a cooked breakfast, check the sausages - about 1.2g.

The idea that you're sitting there effectively downing seawater may seem unsettling enough. But add to this an even more salient fact: our bodies (specifically, the blood) are only a third as salty as the sea - that is, 0.3g per 100g. Every day, we eat on average nine grams of salt, of which about three-quarters comes from processed food, meaning you don't have a chance of avoiding it. This intake stokes up our salt levels beyond what our body needs, forcing us to drink liquid to dilute it. As you get used to large amounts of salt, so you need more to get the same taste. And every mouthful keeps you hooked.

That's good news for the pounds 9bn food and drinks industry, which has a huge investment in making sure that you consume more salt than you require; indeed, more than is good for you, according to a huge body of medical research. The more salt there is in food, the thirstier you feel, perhaps encouraging you to have a sweet, fizzy drink made by the same company that makes the salty food, and the less happy you will be with unsalted - that is, cheaper and unprocessed - food.

And there is a deadly price to pay. The most dramatic example came when an inquest last week heard that the death of three-month old Leroy Elders was caused by excessive salt intake, because his parents had mistakenly tried to wean him too young, using adult food.

Babies' immature kidneys cannot handle much salt, because it quickly builds up in their bodies. The maximum recommended dose for babies less than a year old is 0.53g daily - 17 times less than a typical adult. Leroy's parents fed him on liquidised breakfast cereal, mashed potatoes and gravy made from granules. After the tragedy, and still deeply shocked, Leroy's father David said that baby rice seemed too expensive: "We looked on the [cereal] packet and to us the ingredients, including salt, were the same."

The baby's mother, Joanne, added: "We may be young, but we are not stupid. We know babies should not be given too much salt. I don't like it myself and never use it for cooking. We are certain we did nothing wrong. We just don't understand it."

Contrary to many newspaper claims the next day, the culprit was probably not the breakfast cereal, but the gravy granules, which are typically laced with salt. But one can understand the couple's confusion. Before you read this article, would you have known what the sodium measure on a food label meant?

Prof Graham MacGregor of St George's Hospital medical school in Tooting, London, is a long-time opponent of food manufacturers' excessive use of salt, and he warns of how marked an impact excessive salt can have. "If you eat very salty foods, there are receptors in the mouth which get less sensitive to it, so you need a higher salt concentration to get the same taste. But by contrast, if you stop eating it or reduce the amount, that sensitivity returns: it takes about three or four weeks. Food tastes much better as a result."

While Leroy Elder's case has rightfully grabbed the headlines, there are many more silent deaths. In 1994 the government's committee on medical aspects of food policy (Coma) recommended that the salt content of our diet should be cut by a third, from 9g to 6g daily - and said that doing so would save 34,000 lives a year by lowering blood pressure; strokes would be cut by 22 per cent and heart attacks by 16 per cent.

Imagine for a moment what would happen if a government-appointed committee found that genetically modified food was contributing to 34,000 - or even 34 - deaths per year. It would be off the shelves within hours.

But with salt, whose longstanding use the food industry has an interest in protecting, change is slower. The Tory government did not adopt Coma 1994, as it is known, as official policy. Nor has the Labour government, although two weeks ago Tessa Jowell, the minister for public health, told a conference that research was needed urgently on reduction of salt in food.

It was not quite a declaration of war. But the Food and Drink Federation (FDF), the powerful industry lobby reacted by announcing a six-month study into how much, and what, manufacturers use salt for in their foods. At the same time, though, the FDF insists that Coma 1994 is not official policy, and that "many scientists" think that eating salt can be good for you.

What should we expect from its review? Hopeless optimists might wish for something like the announcement two weeks ago by the Asda, the Co- op and Marks & Spencer supermarket chains, which have recently made significant cuts in salt in their own-brand foods. Asda notably reduced the levels by 10 per cent in two-thirds of its brands.

If they can, why not FDF members? "Our members make the own brands for those supermarkets," said a spokeswoman indignantly. That means it will be easy to follow suit, doesn't it? "Oh, no," said the spokeswoman. "We have anecdotal evidence of manufacturers producing low-salt lines of popular foods which proved unpopular."

Yet Asda's nutritionist, Sue Malcolm, said: "Not one customer noticed when 10 per cent of salt disappeared from Asda loaves of bread."

But labelling something "low salt" can be a commercial kiss of death akin to calling it "high fat". People whose palates are accustomed to salty food will find low salt foods tasteless, and are unlikely to persist while their taste buds adjust.

The FDF insists that its audit will be published by the end of the year. "Until we get the results we won't know if there is scope for reducing its use. Some salt is used for flavouring, some for its preservative effect - after all, it's the oldest preservative known to man."

So cornflakes need salt to stop them rotting? "Well, I don't know, we won't know until we get the results. But the key thing about it is choice," the FDF's spokeswoman said.

Yet choice is the thing that is so sorely missing. "I don't think the Government is going to get far with the FDF because the drinks industry is so powerful," said one industry source who declined to be named. "Any soft drinks manufacturer will be reluctant to see any reduction in salt content in foods."

A SHORT HISTORY OF THE EDIBLE ROCK

n Salt enhances taste, including sweetness, and makes stale or spoiled food edible. Human beings began using it when they began eating vegetables.

n Salt is an edible rock. It can be harvested from the sea through a series of shallow basins or saltings. The sun evaporates it into a concentrated liquor, and the salt then crystallises. It is then passed through lime ponds to be drained, washed, stored and cleaned.

n Animals were once used to find salt because they would lick salt rocks for the taste.

n Salt towns were often the centres for preserving meat or fish before refrigeration was invented. Pork was barrelled with salt and beef was corned or covered with large salt crystals.

n Cheshire has one of the biggest concentrations of salt in the country. People used to acquire the salt by throwing heated stones into salt springs and scraping off the salt crusts that appeared - until Julius Caesar brought "salinators" from Rome to teach the English how to boil brine in lead pans instead.

n The word salary derives from Latin because Roman soldiers used to be partly paid in salt.

n Salt comes out of the sea, as does Aphrodite, the goddess of sex. In Europe, it was once the custom to cure impotence by salting the disobliging penis.

n The silver saltcellar was once a central ornament on the tables of the rich, marking off the close friends of the family from those who were below the salt and less worthy.

n Spilling salt signifies enmity; Judas upsets the saltcellar in Leonardo's Last Supper.

n French kings first started taxing salt in the 14th century. The tax was kept on until 1945 and its abolition during the French Revolution only lasted 15 years.

n England was the first country to abolish salt tax in 1825 for good. The Industrial Revolution had made it much easier to produce salt and increase trade in it.