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Wolfson Institute of Population Health - Barts and The London

Taking Action on Salt: How Queen Mary’s research improved the food on your plate

a jar of salt and a salt shaker on a wooden surface

Professor Graham MacGregor CBE

Professor of Cardiovascular Medicine

Salt is often an overlooked killer: it raises our blood pressure, leading to tens of thousands of unnecessary strokes, heart failures and heart attacks every year.

In the UK, more than one in four of us has high blood pressure. More than half of these cases are caused by consuming too much salt.

We all eat too much salt: on average, in the UK we consume 40% more salt on average than the recommended maximum daily limit of 6g (less than a teaspoonful) and everyone eats more than the 1g per day needed.

Harm on an industrial scale

One reason it is hard for us to monitor how much salt we eat is because so much of our salt intake comes from processed food, much of which doesn’t taste salty and isn’t clearly labelled.

A staggering 75% of our salt is already added to our food by manufacturers.

Born from controversy

The Action on Salt research group was set up by Professor MacGregor in 1996 after the then Conservative Government rejected medical recommendations to reduce salt intake, following pressure from the food industry.

Outrage among many health experts led Professor MacGregor to set up an action group on salt, Consensus Action on Salt and Health (CASH), later renamed Action on Salt, with his research colleagues. The group was founded to counter food industry claims with clear scientific evidence, linking high salt intake to poor health.

The aim was to try to get the food industry to slowly reduce the amount of salt they add to their products and so reduce the nation’s salt intake, without requiring behaviour change.

Taking Action on Salt

Action on Salt, chaired by Professor MacGregor, has comprehensively shown the relationship between salt intake and blood pressure.


In a meta-analysis of 34 trials, Action on Salt showed that even a modest long-term reduction in salt intake – as recommended by the NHS – significantly reduces your blood pressure.
 
Not only that, this reduction happens in people whether or not they have high blood pressure, and regardless of sex, age or ethnicity.

When the group’s work began in 1996, Kellogg’s Cornflakes had 10% more salt by concentration than sea water. The cereal now contains less than half of the level of salt in sea water.

A clear relationship

The meta-analysis also showed a dose-response relationship between a reduction in salt intake and a fall in systolic blood pressure: in other words, lowering your intake of salt by any amount has the effect of lowering the pressure on your arteries.


Moreover, the group demonstrated that if we could further reduce the UK population’s salt intake to 3g a day (from the 6g recommendation), there would be an even greater effect in reducing blood pressure.

The group’s current target is to reduce salt intake to an average of 6g a day for adults (and even less for children), from the current average of 8.41g a day.

Single, most cost-effective solution

Reducing salt in food is one of the most cost-effective public health policies available to the Government. For every £1 spent on salt reduction, £300 is saved in healthcare costs, with the cost of reformulation absorbed by the food industry – one reason the policy is championed by the World Health Organisation.

Leading public health policy

Action on Salt developed a model to reduce salt consumption in the UK which was adopted by the Food Standards Agency with great success.

The model’s six main steps were:

  1. To calculate salt intake by asking survey participants to measure levels of sodium in their urine over a 24-hour period and keep a dietary record of salt sources.

  2. To set a national target for salt intake, and develop a salt reduction strategy to reach it.

  3. To work with the food industry to reduce levels of salt in their products.

  4. To ensure food was clearly labelled with its nutritional value.

  5. To run a consumer awareness campaign.

  6. To monitor the progress of the plan.

In addition, the FSA tasked Action on Salt with independently monitoring the food industry’s progress in reducing salt in 85 product categories.

The group looked at the main sources of salt in the UK diet, including bread (the biggest source), cheese and breakfast cereals.

In 2014, Action on Salt investigated the impact of the 2003-2011 salt reduction policy. Over that period, the salt content of food products was reduced by 20-40%, and population salt intake fell by 1.4g between 2003 and 2011, a 15% reduction. This was accompanied by a fall in the nation’s blood pressure of 3/1.4 mmHg.

These reductions had a significant effect on the nation’s health: deaths from strokes and heart disease fell by 42% and 40% across the same period.

Sliced bread on a wooden surface

Bread is the biggest source of salt in the UK diet

Holding Government to account

In 2010 the Government removed responsibility for nutrition policy from the FSA to the Department of Health and their Public Health Responsibility Deal (PHRD), making the food industry responsible for monitoring their own progress with salt reduction in their products.

Salt reduction targets were no longer officially monitored, dealing a severe blow to the UK’s salt reduction policy – a policy that was regarded as a world leader.

Professor MacGregor and his colleagues highlighted the cost of this move in the British Medical Journal, calculating that four years of the UK’s salt reduction programme were effectively lost. A loss that resulted in 6,000 deaths from stroke and heart attack — 4,000 of which were premature and preventable.

Action on Salt has continually maintained pressure on the food industry and Government. As a result of their campaigning, Public Health England (PHE) was given responsibility for monitoring salt reduction targets in 2017.

Moreover, Action on Salt succeeded in keeping salt in the headlines: it was mentioned as a priority in the Secretary of State for Health’s Prevention Green Paper and in the Chief Medical Officer’s (CMO)’s Annual Report for 2018. The group is regularly included in consultations by Government on its salt reduction targets, including the newly published targets which are due to be met by 2024.

Making your food healthier for you

Action for Salt has had a transformative effect on our nation’s food. When the group’s work began in 1996, Kellogg’s Cornflakes had 10% more salt (sodium) than sea water. The cereal now contains less than half of the salt levels in sea water. A huge reduction which has not affected sales of the product.

The group’s continued pressure on the food industry has seen salt levels fall in processed food. PHE’s analysis of progress towards 2017’s salt reduction targets found that 81% of foods eaten at home (shop label or manufactured products) met maximum salt targets and just over half met average targets. 71% of takeaways and other food eaten outside the home met their maximum target.

If we keep eating salt at 2018 levels, by 2050 the salt reduction programme will have saved 83,100 premature deaths from heart disease and 110,700 premature strokes. It will also have saved £1.64bn in healthcare costs.

Keeping salt in the headlines

Action on Salt hasn’t only campaigned at government and industry level. It also runs a series of public health awareness campaigns, including Salt Awareness Week, successfully spreading the salt reduction message. As a result, salt levels in food remain a main concern for consumers.

The group also has support from many companies committed to reducing salt. In addition to supporting Salt Awareness Week, McCain, Aldi, Waitrose, the Coop and Mars Food met most of the 2017 targets.

Schools, institutes and research centres

Barts and The London School of Medicine and Dentistry

We are firmly embedded within our east London community, with an approach to education and research that is driven by the specific health needs of our diverse population.

Wolfson Institute of Preventive Medicine

We are an internationally recognised centre for research and teaching within Queen Mary's medical faculty, Barts and The London School of Medicine and Dentistry.

Centre for Environmental and Preventive Medicine

We conduct research and teach in all areas of chronic disease epidemiology, medical screening and public health. Our research is focused on elucidating the causes and prevention of disease.