Alarm bells have been sounded that the US government recommended-daily allowance of salt is too high. The scientists who completed the study have now provoked widespread debate concerning salt and the average American diet.

Consumption levels of salt are an important issue in the US, where some 50 million people suffer from high blood pressure, a condition that scientists have agreed for many years can be alleviated with careful cuts in the amount of salt in diets.

The contentious point still be to be resolved is whether salt intake is directly linked to blood pressure. This could mean that those with normal blood pressure would risk low pressure by cutting back on sodium intake.

The study, detailed in the New England Journal of Medicine, believes this is the case. It charted the effects of slat consumption on 412 people over 30 days, where one half followed a typical high-fat US diet and the other was given low-fat and low-cholesterol foods. According to the results, both groups experienced lower blood pressure when salt consumption was reduced, and this was dramatically effective where salt intake was less than 4g a day (2g lower than the government recommendation).

Chairman of the study and associate professor at Harvard Medical School, Frank M. Sacks, concluded that he had no qualms in saying that "for the majority of the American population, reducing salt is important to health."

Supporting this, officials at the National Heart, Lung, and Blood Institute, which funded the study, are challenging health officials by arguing that the government should now lower its recommended daily levels of sodium intake. As it stands, the average American daily diet already contains 50% more sodium than recommended levels.

On the other side, however, food manufacturers and the salt industry are complaining that health officials always "focus on the negative message." Spokesmen for the Grocery Manufacturers of America, Peter Cleary, believes that the best way to reduce blood pressure is by following a healthy diet overall, not just focusing on salt intake.

To read's investigation into the confusion caused by dietary guidelines in the US, click here.