They have found that the level of salt can be significantly reduced without sacrificing taste.

Consuming high levels of salt is known to cause high blood pressure, which in turn can cause heart disease.

The BBC's Richard Hannaford: "Campaigners say food manufacturers should take note and reduce salt levels of processed foods

But many people shy away from a low-salt diet because they think the taste of their food will suffer.

The new research, published in The Lancet on Friday, suggests food manufacturers could cut the level of salt in their produce and consumers would not notice.

Wholemeal loaves

Dr Anthony Rodgers and Dr Bruce Neal, researchers at Auckland University in New Zealand, carried out the study.

They varied the salt levels in loaves of bread - the single largest source of dietary salt.

Doctors recommend avoiding excess salt

They took three types of wholemeal bread, identical except for their salt content, to 60 colleagues who were unaware of which loaf they were eating.

One of the 750g loaves had the standard amount of salt - 3.1g - one had a salt content of 2.8 g - a 10% reduction - and the third loaf had a salt content of 2.5 g - a 20% reduction.

The participants were given one piece of each type of bread and asked to rate its taste and to guess whether the bread had the normal or reduced salt content.

The participants could not tell the difference between the taste of the three types of bread. Nor could they tell which loaf had the normal or reduced salt content.

Large-scale benefits

BBC Health Correspondent Richard Hannaford: "This could lead to a major change in food ingredients"

The authors said: "If these findings were to be replicated for different foods, recommendations could be made to food manufacturers that small reductions in salt content would not reduce sales."

They added that small reductions in the salt content of processed foods would lead to lowering of the blood pressure in the population at large, "with considerable health benefits".

Belinda Linden, a cardiac nurse adviser at the British Heart Foundation, said the research was good news.

"Although it's a small trial it does confirm that there are positive ways in which manufacturers could play a strong part in reducing salt without reducing the taste.

"The strong association that has been found between a high salt intake and increased blood pressure really demands that methods are sought to encourage such small changes and thus produce significant health benefits."

Industry 'wants high salt level'

However, Professor Graham MacGregor, of St George's Hospital, London, said there were huge commercial reasons for keeping the salt content of processed food high.

He said: "If we reduce our salt intake soft drink sales will fall. For these reasons the salt and food and soft drink industries are very reluctant to cut the salt content of processed food.

"We have to persuade them that the health of the population is far more important than their short-term profits."

Martin Paterson, of the Food and Drink Association, said: "There is some over-excitement about the use of salt from some quarters.