Research undertaken by the Wolfson Institute of Preventive Medicine at Queen Mary University of London indicates that salt reduction measures taken in the UK have had a positive effect on the nation’s health.
From 2003 to 2011, there was a decrease in mortality from stroke by 42% and IHD (ischaemic heart disease) by 40%. In parallel, there was a fall in BP (blood pressure) of 3.0±0.33/1.4±0.20 mm Hg (p<0.001/p<0.001), a decrease of 0.4±0.02 mmol/L in cholesterol, a reduction in smoking prevalence from 19% to 14%, an increase in fruit and vegetable consumption and an increase in body mass index (BMI).
Salt intake, as measured by 24 h urinary sodium, decreased by 1.4 g/day (p<0.01). It is likely, said the researchers, that all of these factors (with the exception of BMI), along with improvements in the treatments of BP, cholesterol and cardiovascular disease, contributed to the falls in stroke and IHD mortality.
In individuals who were not on antihypertensive medication, there was a fall in BP of 2.7±0.34/1.1±0.23 mm Hg after adjusting for age, sex, ethnic group, education, household income, alcohol consumption, fruit and vegetable intake and BMI. Although salt intake was not measured in these participants, the fact that the average salt intake in a random sample of the population fell by 15% during the same period suggests that the falls in BP would be largely attributable to the reduction in salt intake rather than antihypertensive medications.
The researchers noted, however, that despite considerable progress being made on salt reduction, the mean salt intake in England (8.1 g/day in 2011) was still 35% higher than the recommended level of 6 g/day, and 70% of the adult population (80% men and 58% women) had a daily salt intake above the recommended level. Therefore, continuing and much greater efforts are needed to achieve further reductions in salt intake to prevent the maximum number of stroke and IHD deaths.
