Reducing salt intake to decrease risk of heart attack and stroke

In summary

Since 2002, City St George’s researchers have provided clinical and epidemiological evidence showing that reduced salt intake significantly lowers blood pressure.

This has led to UK government and WHO recommendations, contributing to a major drop in stroke and heart disease deaths.

What did we explore and how?

Researchers MacGregor and He published a series of studies demonstrating the connection between salt intake and blood pressure.

• A meta-analysis of 28 trials showed that reducing salt intake from 12 to nine grams per day significantly lowers blood pressure in both normotensive and hypertensive individuals.
• Further reductions to six or three grams per day would double or triple the blood pressure-lowering effect.
• Cutting daily salt intake from 12 to three grams could reduce stroke risk by 33% and ischaemic heart disease (IHD) by 25%, preventing about 20,500 stroke deaths and 31,400 IHD deaths annually in the UK.
• Dr He also demonstrated that a low-salt diet in childhood reduces later cardiovascular risk and is linked to reduced sugary drink consumption, potentially aiding in childhood obesity prevention.

Benefits and influence of this research

• In 2003, the Scientific Advisory Committee on Nutrition recommended salt reduction, triggering a national awareness campaign.
• UK salt intake fell from 9.5g/day in 2003 to 8.6g/day by 2008, preventing an estimated 6,000 cardiovascular deaths and saving £15 billion.
• The UK food industry responded with clearer packaging and reformulation.
• In 2011, NICE published guidance on cardiovascular disease prevention, citing this research and recommending salt reduction to 6g/day by 2015 and 3g/day by 2025.
• NICE’s hypertension management guidelines also advised dietary salt reduction.
• A 3g/day salt reduction is estimated to prevent 14,000–20,000 cardiovascular deaths per year, save £350 million in healthcare costs, and add 130,000 quality-adjusted life years.
• The World Health Organization adopted similar global salt reduction goals based on this research.