Susan Jebb OBE, Professor of Diet & Population Health in the Nuffield Department of Primary Care Health Sciences at the University of Oxford, responds to questions on the impact of salt in the diet on health. Professor Jebb is Chair the DH Public Health Responsibility Deal Food Network which develops voluntary agreements with industry to improve the food environment.
What is the evidence for salt in the diet being harmful?
A large number of studies have been conducted which support the concept that salt intake is a major risk factor for high blood pressure. The diversity and strength of the evidence is much greater than for many other lifestyle factors. The World Health Organisation estimated that in 2010, 1.7 million annual deaths from cardiovascular causes were attributed to excess salt intake.
In the UK in 2003, the Scientific Advisory Committee on Nutrition (SACN) published its report on Salt and Health. SACN concluded that the evidence of a link between a high salt intake and high blood pressure was stronger than it had been when the issue had last been considered in the early 1990’s. SACN also concluded that a reduction in the average salt intake of the population would proportionally lower population blood pressure levels and confer significant public health benefits by reducing the risk of cardiovascular disease. SACN recommended that the average salt intake of the population should be reduced from the then current levels of 9.5g to 6g per day, with lower levels recommended for children.
Are low sodium salts, such as potassium chloride, acceptable alternatives to sodium chloride?
The Department of Health does not currently recommend the use of potassium-based salt replacers, because replacing the flavour of salt will not allow palates to adjust to lower salt levels. In addition there is a subgroup of the population, especially older people, who have impaired kidney function and there is a potential risk of increasing potassium intakes for these vulnerable groups.
However, technical limitations in salt reduction in certain product categories and the potential for health gains from further reductions in sodium intake if it was replaced in whole or in part with potassium-based alternatives has prompted a review of the evidence. The Scientific Advisory Committee on Nutrition and the Committee on Toxicity are assessing both the health risks and benefits of potassium-based sodium replacers with particular reference to vulnerable groups. The outcomes from the review are expected in the coming months.
What is the Government doing to help reduce salt in UK diets?
The UK Government has had a sodium reduction strategy for many years and this continues. An important part of this strategy is the partnership with the food industry to reduce the salt content of a broad cross-section of foods, through reformulation of existing products and the introduction of alternative lower salt products.
To support this reformulation programme, salt targets for 76 categories of food have been established which should be met by 2017. These replace the previous 2012 and initial 2007 salt targets and challenge industry to reduce further the amount of salt in everyday foods. In addition, targets have been set on the basis of maximum salt per serving for some of the most popular dishes consumed outside the home. All the major supermarkets and many big name manufacturers and caterers have made voluntary commitments to work towards these targets to reduce salt in their products.
So far, reductions of up to 50% have been seen in popular items, such as table sauces, soups and baked beans. The average salt content of bread has reduced by around 20% and similar reductions have been achieved in some products, such as oven chips, ready meals and breakfast cereals.
The UK strategy also includes consumer education about salt and health. The new colour-coded nutritional labelling on the front of many products makes it easier than ever before for consumers to know the amount of salt in a product and to be able to select the lower salt items.
How successful have we been at reducing salt consumption in the UK?
The UK’s work on salt reduction is world leading. We have reduced average daily salt intakes by 15% from 9.5g in 2000/01 to 8.1 g in 2011. This is primarily due to the efforts by industry to reformulate a wide range of products to lower the salt content. We estimate that this has saved around 6000 lives each year and UK businesses have every reason to be proud of this ground breaking work. But we must also recognise that we have a lot further to go to reach our 6g per day goal and reduce the burden of diet-related ill-health.
This is not a task that can be left just to the most willing and progressive companies – we need everyone to play their part to reduce the number of premature deaths from heart disease and stroke.
Increasingly we also need more consumers to be aware of the amount of salt in their food and the effect it has on their health. This means eating salty foods less often as well as always choosing varieties with the lowest salt content.
Many food manufacturers have already substantially reduced salt in processed foods and ready meals; can further salt reduction be achieved without reducing the palatability of foods?
Yes. We know that people’s palates can adjust to lower salt levels, so by making gradual step-wise reductions over time, businesses should be able to take their customers with them. Many businesses have worked closely with their customers to find the best approaches to reducing salt, taking into account issues of taste, quality and safety.
It is however extremely important that out of home businesses make greater progress on salt reduction to help ensure that the consumer palate is not exposed to high salt flavours through meals eaten in restaurants and takeaways, which might undermine the work on salt reduction achieved elsewhere in the industry.
As a result of investments in research, there are also some innovative solutions coming onto the market which deliver a similar flavour or functional properties in foods but with less sodium. This research will be increasingly important as reformulation efforts progress.
We are used to adding salt to food to make it taste better; how can we persuade consumers to reduce their salt intake?
Using salt during cooking or at the table is a habit and habits can change, but we know it takes time and people need support.
The Change4Life campaign provides advice and helpful tips for consumers to help them reduce the amount of salt they eat – by checking the labels, using herbs and spices for flavour in place of salt and avoiding having a salt cellar by the cooker or on the table. ‘Watch the salt’ has its own section on the Change4Life website with a guide to foods high in salt and tips for swapping. Lower salt recipes are available on the website and in a mobile app. Salt swapping messages are included in campaigns, for example in the Be Food Smart meal mixer (2013) and Smart Swaps taster recipe and smart swapper tools (2014), and messages are also included in the emails which are sent out to people who sign-up to Change4Life. The NHS Choices website also provides information to the public on the risks of eating too much salt and tips on how to eat less. In addition, TV and radio adverts remind us all to watch our salt intake and to use the colour coded food labels to identify lower salt options – by buying foods with more greens and fewer red symbols. Social media is also used to deliver salt reduction messages at intervals throughout the year.
Research shows that much of our behaviour in relation to food is not conscious but anautomatic response, shaped by the circumstances in which we find ourselves and the environment and social cues that surround us. Increasing knowledge and encouraging greater personal responsibility for the food we eat is necessary, but it’s not sufficient. That’s why we need a combination of industry action and consumers motivated to look for lower salt choices.
How can we reduce our salt intake from food consumed outside the home?
We know that food served in restaurants and takeaways tends to be saltier than similar foods eaten at home. The manufacturing and in home retail sectors have shown what can be achieved – they need to continue to set the pace, maintaining their investment in innovation to meet the technological challenges. But the high street must catch up and fast. Eating out is a sociable, pleasurable activity and it should not undermine our health.
The food service sector is complex and diverse, but there are a range of opportunities available to enable caterers and their suppliers to play a fuller part in salt reduction. This includes action with regard to chef training, kitchen practice and salt availability, reformulating menu items, providing information on salt content to consumers and procuring lower salt ingredients. In addition, specific maximum per serving targets for the out of home sector have been developed to limit the amount of salt in the ten most popular items on menus and in children’s meals. A survey by Consensus Action on Salt and Health (CASH) published during Salt Awareness Week in March this year highlighted that too many of the meals specifically targeted at children contain excessive amounts of salt. It is time that these businesses, many of which profess to be family friendly chains, committed to meeting the salt targets and to helping ensure children’s palates do not become accustomed to high salt flavours.
We need to train the next generation of chefs and caterers that healthy eating is consistent with providing a positive customer experience and developing a profitable business and we probably haven’t invested as much in this area as we would like. However, organisations, such as the BNF (British Nutrition Foundation), are developing training materials for chefs to help them develop foods which taste great but which are healthier for customers too.
Can we rely on voluntary agreements to meet health targets?
I am a great believer that when it comes to reformulation we can achieve more through voluntary action than legislation because companies that recognise the importance of this agenda will generally go further and faster than if they are simply required to meet a minimum mandatory standard. We’ve seen some fantastic progress on salt reduction by many companies – the challenge is how we can reward the best and chastise the rest to step up to the mark in order to accelerate the pace of change.
However in some areas we may need to introduce more stringent measures. For example the setting of mandatory standards for food in schools which limit the number of times foods high in fat, sugar and salt can be served. When progress through voluntary initiatives is slow or inadequate it makes good sense to consider other options too.
Susan Jebb is Professor of Diet and Population Health at the Nuffield Department of Primary Care Health Sciences, Medical Sciences Division, Oxford University and Chair the DH Public Health Responsibility Deal Food Network
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