Salt levels vary significantly in different soups, according to a new survey by the UK's Food Standards Agency.

Many soups contained as much as a third of the recommended maximum daily intake for an adult per serving, while some contained as much as half. 

The survey looked at the salt content in the canned, fresh/chilled and dried soup categories and revealed that not only is there wide variation within each category but there is also wide variation within each flavour. The dried soup category ranged from 1.2g to 2.9g of salt per serving, while two brands of canned mushroom soup contained twice the amount of salt of another canned mushroom brand. No brand was consistently high or low in salt.

The recommended maximum daily intake for salt is 6g, and on average adults are currently exceeding this by 3.5g. The FSA launched a public health campaign in September 2004 to highlight the increased risk of high blood pressure, heart disease and stroke that has been linked to eating too much salt.

"The results show a considerable variation in the level of salt in soups. We welcome the commitment that some manufacturers and retailers have made to reduce salt content in soups but the fact that such a popular and convenient food can provide more than a third of the daily salt limit shows that continued effort in this area is still needed," said Gill Fine, director of consumer choice and dietary health at the FSA.

The Food and Drink Federation, which represents UK food and drink manufacturers, said companies have been reducing the salt content of soups and sauces since last year.

"However, we can only move at the pace dictated by consumers. A reduced salt product which is left on the shelf or to which consumers add salt at the table, will not benefit anyone," said the federation's deputy director general, Martin Paterson.

The FSA also noted that six Campbells soups within the survey did not include salt or sodium content information on the label, adding that it recommends that full nutrition information be provided on all foods.