Reducing high salt intake could lead to a large reduction in cardiovascular disease

Reducing high salt intake could lead to a large reduction in cardiovascular disease

A modest reduction in daily salt intake of just 1g could stave off nearly 9 million cases of heart disease and stroke and save 4 million lives by 2030, according to estimates from a modeling study published in the open access journal BMJ Nutrition Prevention & Health.

Salt consumption in China is one of the highest in the world, at an average of 11g/day - more than double the amount recommended by the Chinese government. High salt consumption increases blood pressure and therefore the risk of cardiovascular disease, which accounts for 40% of all deaths in China each year.

Researchers set out to estimate the health benefits that could be achieved by reducing salt intake across the country, with the aim of supporting the development of a viable salt reduction program.

They compiled the latest and most reliable figures for population size, salt intake, blood pressure and disease rates by region and age, then estimated the effects on cardiovascular health for three different approaches.

The first of these was a reduction in salt intake of 1 g/day, which should be achieved within a year. The second was the WHO interim target of a 30% reduction by 2025, which corresponds to an incremental reduction of 3.2 g/day.

The third was to reduce salt intake to less than 5 g/day by 2030, the goal set by the Chinese government in its health and development action plan, Healthy China 2030.

They then estimated the drop in systolic blood pressure — the higher number in a blood pressure reading that indicates the force with which the heart pumps blood throughout the body — and the subsequent risk of heart attacks/strokes and deaths from cardiovascular disease.

Given that adults in China consume an average of 11 g of salt per day, a reduction of 1 g per day should reduce average systolic blood pressure by about 1.2 mmHg. And if this reduction were achieved within a year and sustained, about 9 million cases of heart disease and stroke could be prevented by 2030 - 4 million of which would be fatal.

If this continues for another 10 years, around 13 million cases of heart attacks and strokes could be prevented - 6 million of them fatal.

In order to achieve the WHO's interim target by 2025, salt intake would have to be reduced by 3.2 g/day. If this were to be maintained for another 5 years, a cumulative total of around 14 million cases of heart disease and stroke could be prevented by 2030 - 6 million of which would be fatal.

And if this continues through 2040, the cumulative total could reach about 27 million cases, 12 million of which are fatal.

To achieve the Healthy China 2030 goal, salt intake would need to be reduced by 6 g/day, which would lower average systolic blood pressure by just over 7 mmHg and prevent 17 million cases of heart disease and stroke - 8 million of them fatal.

The benefits of reducing dietary salt intake would benefit men and women of all ages across China, the researchers say.

There may also be additional health benefits that the researchers were unable to estimate due to a lack of relevant data: These include secondary prevention of cardiovascular disease and reductions in cases of chronic kidney disease and stomach cancer, rates of which are already high or rising in China, they suggest.

"The Chinese government's 'Healthy China 2030' action plan contains dietary recommendations to reduce salt, sugar and oil intake. This modeling study shows that salt reduction alone could bring enormous health benefits to the entire population of China," said the researchers. and added that a 1g reduction in daily intake “would be easily achievable”.

But they emphasize: "Our estimates are based on not only achieving salt reductions but also maintaining them over time, which can be a major challenge given China's rapidly changing dietary habits given its rapid urbanization."

They conclude: "The evidence for the significant benefits of salt reduction in China is consistent and convincing. Achieving and maintaining salt reduction in the population in China could prevent millions of unnecessary cardiovascular events and deaths. Given the sheer size of the Chinese population, it would also bring major benefits to global health."

Modeling studies like this provide an indicator of how specific dietary changes have the potential to alter the course of diet-related diseases.”

Shane McAuliffe, Director, Science and Digital Communications, NNEdPro Global Center for Nutrition and Health

"Given the established dose-response relationship between salt intake, systolic blood pressure and cardiovascular disease, reducing the intake of one of the world's largest consumers would have a significant impact on population health - something that has already been achieved in other countries worldwide," he adds.

Source:

BMJ

Reference:

Tan, M., et al. (2022) Reducing daily salt intake by 1 g in China could prevent nearly 9 million cardiovascular events by 2030: a modeling study. BMJ Nutrition Prevention & Health. doi.org/10.1136/bmjnph-2021-000408.

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