Dresden, Germany  - Eating an egg for breakfast in peace is not always easy given the common admonition, "Don't use so much salt!"

While high consumption of table salt has long been blamed for high blood pressure, some scientists now are not so sure.

Beyond dispute, however, is that the human body's fluid balance and absorption of nutrients depend on salt, which maintains osmotic pressure in the lining of blood vessels, explained Stephan Bischoff, a professor of nutritional medicine at Hohenheim University in Germany.

Hence salt enables the passage of nutrients into cells, and of waste out of them. It is also important in areas including the transmission of nerve impulses, muscle movement and bone density.

"Salt also causes the body to retain water," Bischoff said, pointing out that a salt deficiency could lead to dehydration.

An adult requires a daily minimum of 1.4 grams of salt to compensate for the salt lost normally by the body. Sweating or diarrhoea can greatly raise the requirement. "Sweat contains between 0.8 and 1.3 grams of table salt per litre," noted Karl-Ludwig Resch, professor of physical medicine and rehabilitation at Dresden University.

Generally speaking, a person's salt intake exceeds the minimum daily requirement many times over. Men in Germany consume 8.78 grams daily on average, and women
6,33 grams, according to the National Nutrition Survey II. The survey was conducted by the Karlsruhe-based Max Rubner Institute (MRI), a federal research institute specializing in nutrition and food.

"One reason for the difference is that women eat fewer salted meat products," explained MRI spokesperson Iris Lehmann.

Salted meat products such as sausage and salami - 100 grams of the latter contain about 3.1 grams of salt - are not the only sources. Among the saltiest foods are some varieties of cheese.

"Processed foods, and particularly canned foods, are also very high in salt," said Professor Walter Zidek, director of the Nephrology Clinic at Berlin's Charite Univerity Hospital.

So how much salt is healthy? The question is not easy to answer. The standard given by the Bonn-based German Nutrition Society (DGE) is 6 grams daily for adolescents and adults, with an upper limit of 10 grams.

"Exceeding this amount could lead, in individual cases, to negative consequences for health," said DGE spokesperson Antje Gahl.

The guarded phrasing reflects the fact that salt intake is no longer generally linked to high blood pressure or hypertension.

"There has been no reliable study proving that the average salt intake in the healthy population contributes to high blood pressure," Resch remarked. He said there were many possible causes of high blood pressure and "many ways to lower it, too," among which reducing the consumption of table salt was one of the least effective.

According to Resch, simply gaining four or five kilogrammes affects blood pressure two to three times more than anything achievable by reducing salt intake.

There are no uniform recommendations on how much salt a person should consume. While Zidek says a diet low in salt would do no one any harm, Resch advises against a strict low-salt diet. "A healthy person with fairly normal blood pressure need not worry about salt consumption," Resch said.

In any case, a diet rich in fresh foods and low in processed ones would seem to be on the safe side. (dpa)