The research, which looked into the outcomes of a 10% reduction in salt consumption over 10 years in 183 countries found that even a ‘soft regulation' approach, where the food industry worked to agreed goals, along with public education, would still prove highly cost-effective.
These conclusions would still be applicable even without accounting for potential healthcare savings.
Salt, along with sugar and fat, has been subject to intense action by health campaigners, who advocate significant reductions in salt content in everyday foods as a major step to improving population health.
A potential barrier for implementing these approaches is cost. Many European countries have finite resources to improve health, requiring measured evaluations of cost and cost effectiveness.
As of 2012, 29 European nations, consisting of all EU Member States as well as Norway and Switzerland, had salt reduction initiatives in place.
In a UK and US collaboration involving researchers from the Institute for Fiscal Studies and the Cambridge Institute of Public Health, a range of scenarios were evaluated.
This included 10% and 30% proportional reductions and 0.5 g/day and 1.5 g/day absolute reductions in sodium intake over 10 years.
Global salt intake and its effects on blood pressure levels and cardiovascular disease, each by age and sex, were assessed in 183 countries.
Country-specific costs of a sodium reduction policy were estimated and country specific impacts on mortality and disability adjusted life years (DALYs) were modelled using risk assessment methods.
DALYs are the value in years that would otherwise be lost to cardiovascular disease.
Of these, about 42% were attributable to coronary heart disease, 40% to stroke and 18% to other types of cardiovascular disease.
To maintain the same standard, all costs were concerted to international dollars (I$).
One I$ in one country was defined as the funds needed to purchase the same amounts of goods or services in that country as one US$ would purchase in the US.
Across the major European countries, estimated cost effectiveness of sodium reduction for the United Kingdom was 184,120 DALYs averted per year at a cost of I$465.59 per DALY saved.
Germany achieved figures of 299,996 DALYs at a cost of I$311.28 per DALY saved.
Meanwhile, the team recorded figures for France at 147,200 DALYs averted per year at a cost of I$ $506.75 per DALY saved.
“We know that excess dietary salt causes hundreds of thousands of cardiovascular deaths each year," said senior and corresponding author Dr Dariush Mozaffarian, dean of the Friedman School of Nutrition Science and Policy at Tufts University in Boston.
"The trillion-dollar question has been how to start to bring salt down, and how much such an effort would cost."
Dr Mozaffarian added that judging cost-effectiveness of medical interventions in the US used thresholds of either less than $50,000 per DALY or less than $100,000 per DALY.
“Statin drugs, one of the most cost-effective therapies to prevent cardiovascular disease, currently have an estimated cost-effectiveness of about $37,000 per DALY in the US,” he explained.
“The sodium reduction, on the other hand, would have a cost-effectiveness of $332 per DALY."
The study modelled its program on an example set by the UK, which included government-backed industry agreements to reduce salt content in processed foods.
Here, collaborations were set up between national government offices focused on nutrition (Food Standards Agency) and health (ministers of public health).
Non-governmental advocacy organisations such as the Consensus Action on Salt & Health (CASH) were also invited to give feedback.
The UK strategy maintains pressure on food manufacturers to adopt progressive reformulation, encouraged by food group specific targets, independent monitoring, and a sustained media campaign against excess salt intake.
"However you slice it, national salt reduction programs that combine industry targets and public education are a 'best buy' for governments and policy makers," Dr Mozaffarian stated.
Source: British Medical Journal (BMJ)
Published online ahead of print: doi.org/10.1136/bmj.i6699
“Cost effectiveness of a government supported policy strategy to decrease sodium intake: global analysis across 183 nations.”
Authors: Dariush Mozaffarian et al.