Comment from Consensus Action on Salt and Health on the Salt Manufacturers’ Association’s attack on the FSA salt campaign

7th October 2005

A recent press release from the Salt Manufacturers’ Association claims that the FSA’s call to restrict salt intake to 6g a day would be dangerous for ‘many thousands of people’, including athletes, the elderly and pregnant women.

In reality, there is no evidence to support these scare-mongering claims:

• In the elderly, the evidence shows that restricting salt to 6g per day is enormously beneficial.  People over the age of 60 who reduce their salt intake to the recommended 6g per day can reduce their risk of a stroke by up to 31% and their risk of a heart attack by up to 24% in a matter of days. (1)

• In athletes, the amount of salt lost in sweat depends on the amount of salt eaten.  If you eat a lot of salt, your body will excrete a lot of salt in sweat. There is no evidence that reducing salt intake to 6g a day would result in any reduction in performance or cause any other harm to an athlete.  Indeed, careful scientific experiments in the US Armed Forces showed that under conditions of extreme heat stress and prolonged exercise the recruits on the low salt diet (4g/day) performed just as well as the recruits on the higher salt diet (8g/day) (2)

• With regard to pregnant women, the Cochrane Systematic Review showed that salt reduction neither increased nor decreased pregnancy-induced hypertension and the authors concluded that it should be “a matter of choice as to whether pregnant women choose to restrict their salt intake.” (3)

“Of course we understand why the SMA continually tries to suggest that the evidence for a 6g limit to our salt intake is flawed – the profits of their members depend on salt sales,” says Professor Graham MacGregor, Chairman of CASH.  “But we must not let their unsubstantiated claims deflect from the vital message that reducing salt intakes to 6g per day will save 35,000 lives a year.”

(1) These calculations of reduction in risk for older people are based on two papers published in the Lancet (Cappuccio et al. Lancet 1997;350:850-854, and Prospective Studies Collaboration Lancet 2002:360:1903-1913).

The first paper is a randomised double-blind salt reduction trial in older individuals (average age: 67 years). From this study we estimated that a reduction of 6g/day in salt intake (e.g. from the current intake of 12g/day to the recommended level of 6g/day) would cause a fall in systolic blood pressure of 8.7 mmHg in the older population.

The second paper is a meta-analysis of one million adults in 61 prospective studies looking at the relationship between blood pressure and cardiovascular risk. With the information on systolic blood pressure from this meta-analysis, we calculated the reductions in stroke and ischaemic heart disease that would occur with a fall in systolic of 8.7 mmHg in the older population.

2. Armstrong LE et al (1993). Responses of soldiers to 4-gram and 8-gram NaCl diets during 10 days of heat acclimation. In Nutritional needs in hot environments: Applications for military personnel in field operations. Pp247-258. National Academy Press. Washington DC.

3. Duley-L, Henderson-Smart D (1999). Reduced salt intake compared to normal dietary salt,  or high intake, in pregnancy. The Cochrane Database of Systematic Reviews 3: CD001687.