HealthDay News — Reductions in dietary salt was likely an important contributor to substantial decreases in stroke deaths and ischemic heart disease in England in recent years, an analysis of nationwide data suggests.
From 2003 to 2011, stroke mortality fell 42% (P<0.001) and the incidence of ischemic heart disease declined 40% (P<0.001), Feng J. He, PhD, of the Queen Mary University of London, and colleagues reported in BMJ Open.
These reductions correlated with decreases in salt intake of 1.4 g/day (P <0.01) as measured by 24-hour urinary sodium. In 2003-2004, the United Kingdom instituted a nationwide salt reduction program that effectively reduced population-wide salt intake by 15% in 2011.
“To determine the relationship between this reduction in salt intake and the fall in blood pressure and mortality from stroke and ischemic heart disease, we analyzed the data from a series of health surveys carried out in a nationally representative sample of the population in England,” the researchers wrote.
Survey data included BP measurements from Health Survey for England participants, 24-hour urinary sodium measurements from National Diet and Nutrition Survey participants and death data from the Office for National Statistics.
The average salt intake in 2003, before the national salt reduction initiative, was 9.5 g/day. This fell to 9 g/day in 2005-2006, 8.64 g/day in 2008, and 8.1 g/day in 2011 — representing a 1.4 g/day reduction (15%; P<0.05) over the course of the study period.
During the same time period, significant findings in a random sample of the population included a 3.0/1.4 mmHg decrease in systolic and diastolic BP (P<0.001 for both), a 0.4 mmol/L decrease in cholesterol (P<0.001), a decrease in smoking prevalence from 19% to 14% (P<0.001), an increase in fruit and vegetable consumption (0.2 portion/day, P<0.001) and an increase in BMI (0.5 kg/m², P<0.001).
In an analysis of people not taking antihypertensive medications, BP decreased 2.7/1.1 mmHg (P<0.001) from 2003 and 2011 after the researchers adjusted 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, average population-wide salt intake declined 15% during the same period, and “is likely to be an important contributor to the falls in BP,” according to the researchers.
Despite the progress, mean salt intake in England is still 35% higher than the recommended 6 g/day and more than half of adults exceed that amount, they noted.
“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.”
Disclosures: One author is an employee of the nonprofit, charitable organization Consensus Action on Salt & Health.