There are opinions about whether salt contributes to hypertension (blood pressure) and the possible health effects. Less salt has been found to reduce blood pressure, at least in the short term, in older, hypertensive patients.
It is less conclusive whether a lower blood pressure from reduced salt has ultimately worse health outcomes, such as heart attacks. The policy of the Department of Health is to reduce the average daily adult intake of salt from the 9,500 mg (see above) to 6,200 mg. The Government included a mandatory standard for sodium of 200 mg/l in the Drinking Water Regulations, primarily as a measure to help prevent infant hypernatraemia and secondly to assist reducing the sodium intake in the general population.
This policy is not universal, however. In most of the European Union Member States, the national regulations have directly reflected the European Drinking Water Directive which lists sodium as an indicator parameter, which does not contribute to the definition of wholesomeness. When the specification for an indicator parameter is exceeded, the level of non-compliance must be considered to determine whether there is any risk to health and remedial action taken where appropriate. In the USA there is no limit on sodium in the National Primary or Secondary Drinking Water Regulations.
In the new, Third Edition of the World Health Organisation’s Guidelines on Drinking Water Quality, 2003, there is no sodium guideline. It only states that concentrations in excess of 200 mg/l may impart a taste.
It is the Department of Health that recommended limiting sodium concentrations to 200mg/l in drinking water for babies and those individuals on a medically-prescribed, salt-restricted diet.
There are some bottled waters containing over 1700 mg/l of sodium and they are marketed as a health related benefit!