Mandatory limits should be imposed on salt in bread – here’s why

Reducing salt in processed foods is the most cost-effective way to tackle cardiovascular disease

The Irish Heart Foundation (IHF) recently launched a compelling new report Primary prevention of cardiovascular disease: Best practices and lessons for Ireland.

The position paper compiled by Prof Ivan Perry and Ms Kerrie Gallagher from the School of Public Health, University College Cork (UCC), recommends radical action – similar to Ireland’s 2004 ban on smoking in the workplace – to deal with cardiovascular disease (CVD) and other serious diseases.

“Without the implementation of bold policy initiatives, we can expect continued and increased deaths and ill health driven by risk factors,” warned Prof Perry.

Key recommendations include a complete ban on the marketing of food and drinks high in fat, sugar, and salt, and an increase in the legal age to be sold tobacco from 18 to 21.

But the evidence shows that a mandatory limit on salt in the manufacture of bread and other processed foods leads the way as the cheapest strategy to reduce CVD.

CVD remains one of the top causes of premature death and disability in Ireland, accounting for 8,753 deaths or just over a quarter (26.5 per cent) of all deaths in 2021. Diet is a key risk factor for CVD via indirect effects on risk factors, such as body weight, diabetes, and blood pressure (BP). The evidence shows that poor diet is the single biggest risk factor for chronic illness – exceeding the combined effects of tobacco, alcohol, and physical inactivity.

A critical risk factor is salt. As BP rises, so does the risk of CVD, starting at 115/75mmHg. But contrary to what you would expect, most CVD events occur in individuals at the lower end of the BP scale of approximately 130/80mmHg because of the larger numbers of people in the population with BP at this level.

Critical

Given that clinical guidelines do not recommend treating these individuals at the lower end of the scale with BP lowering drugs, population-wide interventions that focus on the underlying causes of BP – including suboptimal diet, physical activity levels, and alcohol intake in the whole population are critical to reducing levels of CVD in that population.

Mounting evidence over several decades shows clearly that high levels of salt in the diet is the major cause of raised BP and that a reduction in salt intake lowers BP and cardiovascular risk.

The most compelling evidence comes from a study published in the New England Journal of Medicine (2022) involving pooled data from 10,709 adults from six studies across the US and Europe, followed up over an average of 8.8 years. The study found that higher salt intake was significantly associated with higher risk of CVD with a daily salt intake of between 5g and 15g.

A US modelling study estimated that reducing dietary salt by 3g per day would reduce annual numbers of deaths by between 44,000 and 92,000; heart attacks by between 54,000 and 99,000; and strokes by 32,000 to 66,000.

In terms of expenditure, this amounts to significant savings of $10 billion to $24 billion in healthcare costs every year.

The cardiovascular benefits of reduced salt intake are similar to population-wide reductions in tobacco use, obesity, and cholesterol levels. While people are well aware of the harms caused by tobacco, obesity, and cholesterol, relatively little attention is paid to salt, either in processed food including bread, or sprinkled liberally on everything from a boiled egg, a bowl of porridge, or a plate of chips.

The World Health Organisation has set a global target of reducing the population salt intake from the current level of almost 10g daily in most countries to less than 5g daily.

There is limited data on current levels of salt intake in the population in Ireland. The most recent data comes from two studies in 2007 and 2008-2009, which found an average salt intake per day of 10.3g for men and 7.4g for women. With increasing levels of ultra processed foods in the national diet over the last two decades, these figures are likely to be even higher in 2024.

The evidence clearly shows that ‘downstream’ measures, such as one-to-one personal advice and food labelling, are markedly less effective than ‘upstream’ activities, such as regulation and market control.

Without the implementation of bold policy initiatives, we can expect continued
and increased deaths and ill health driven by risk factors

According to the IHF report, an Australian study (2012) estimated that “best value for money (by a considerable margin) is achieved by mandating moderate limits on salt in the manufacture of bread, margarine, and cereals”.

In April 2022, the Spanish government introduced a mandatory limit of 1.31g of salt per 100g of bread (13.1g of salt per kilogram of bread). The mandatory upper limit was announced in May 2019, giving the food industry three years to make the required adjustments to manufacturing processes. Prof Perry noted in his report that mandatory reformulation is permissible under current EU single market regulations.

“We recommend that Ireland adopt a similar approach and specify mandatory upper limits to the salt content of bread, and other major sources of salt in the Irish diet, such as processed meat, with a two-to-three-year lead-time.

“This would lead to significant reductions in population-level salt intakes in Ireland, with positive impact on CVD morbidity and mortality,” Prof Perry concluded.

Evidence

He added that the impact would be greatly advanced if it formed part of a suite of measures that included food labelling, public sector procurement, and mass media campaigns, similar to approaches used in Finland and Japan.

There is robust evidence to show that mandatory limits on the salt content of bread and other processed foods is one of the most effective, cost-effective, and equitable approaches to management of CVD.

But will the evidence be enough to sway the Government into action?

The Secretary General of the Department of Health Mr Robert Watt has spoken of the importance of illness prevention and promoting healthy ageing. At a recent joint Oireachtas committee on health hearing to discuss the €22.5 billion Budget allocation for 2024, Mr Watt referred to the challenge of treating ever increasing numbers of patients in acute hospitals under our existing structures and pathways.

“Public health initiatives, in particular the early and continuous prevention of illness, and the promotion of healthy ageing, will be integral to the effective functioning of our future healthcare system,” Mr Watt said.

“Ultimately we are aiming for a country where patients are able to live longer, better lives, and are not only treated but supported by our healthcare services in achieving this.”

A comprehensive evidence-based report has been published demonstrating the efficacy of mandatory limits on the salt content of bread and processed meat to radically alter risk, prevalence, and mortality of CVD in Ireland.

Prof Perry’s team in the UCC School of Public Health and the IHF have provided the Department of Health with a ‘gift horse’ just when they need it most.

How long will it take for Minister for Health Stephen Donnelly and the Department of Health to see it that way?