Less Salt Likely Key Player in Stroke Death Decline

A new study concludes that lower dietary salt intake appears to have played a key role in the significant reduction of stroke deaths seen in recent years in England.

Researchers at the Wolfson Institute of Preventive Medicine (London, United Kingdom) used data from the Health Survey for England—an annual survey of the English population living in private homes—to determine the relationship between the reduction in salt intake in England and blood pressure (BP), as well as mortality from stroke and ischemic heart disease (IHD). The surveys included in the study were from the years 2003 (9,183 participants), 2006 (8,762), 2008 (8,974), and 2011 (4,753), and were comprised of participants aged 16 or older with recorded BP measurements.

The results showed that from 2003 to 2011, deaths from stroke decreased by 42% and deaths from ischemic heart disease fell by 40%, parallel with decreases in salt intake of 1.4 g/day (or 15%), as measured by 24-hour urinary sodium. The study also found reductions in systolic and diastolic BP of 3.0/1.4 mmHg; a decrease of 0.4 mmol/L in total cholesterol; a decline in smoking prevalence (from 19% to 14%); an increase in fruit and vegetable consumption, and an increase in body mass index (BMI) for the population as a whole by 0.5 kg/m2. The study was published on April 14, 2014, in BMJ Open.

“Despite considerable progress being made on salt reduction, the mean salt intake in England was still 35% higher than the recommended level of 6 g/day, and 70% of the adult population had a daily salt intake above the recommended level,” concluded lead author Feng He, PhD, and colleagues. “Therefore, continuing and much greater efforts are needed to achieve further reductions in salt intake to prevent the maximum number of stroke and ischemic heart disease deaths.”

The United Kingdom initiated a nationwide salt reduction program in 2003/2004, which resulted in a 15% reduction in population salt intake by 2011. At the same time, average population BP has fallen and cardiovascular disease (CVD) mortality has also declined. While this can be attributed to various factors, such as changes in diet and lifestyle and improvements in the treatments of BP, cholesterol, and CVD, an analysis has shown that antihypertensive medications accounted for less than 25% of the systolic BP decline over the period.

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Wolfson Institute of Preventive Medicine