Dietary Sodium / Salt

Effect of salt/ sodium intake on cardiovascular health

Cardiovascular Disease

• 'The evidence for adverse cardiovascular effects of sodium […] indicate an association of increased risk of morbidity and mortality from cardiovascular diseases with increasing sodium intake.'

• Because of the well-established relationship between blood pressure and cardiovascular disease outcomes,' there is moderate quality evidence that 'reduced sodium is beneficial for reducing risk of cardiovascular disease.'
• 'High and moderate-quality evidence that consuming <2 g sodium/day compared with consuming ≥2 g sodium/day is beneficial for reducing blood pressure and risk of cardiovascular disease […] in adults.'

• '… sodium intake is positively associated with an increased risk of stroke and cardiovascular events and mortality among the general adult population.'

• 'There are […] convincing data that high salt intake has an indirect effect on the risk of cardiovascular diseases, which is mediated by the level of blood pressure'.
• '…a direct associ­ation between high salt intake and the risk of cardiovascular diseases is not unambiguously clear. The evi­dence is disparate or even inconsis­tent, so that there is currently no unambiguous proof that high salt intake directly increases the risk of cardiovascular disease'.

• 'In aggregate, the data indicate a relationship between higher sodium intake and higher risk of CVD.'

Coronary Heart Disease

• '… an association of increased risk of morbidity and mortality from cardiovascular diseases, including coronary heart disease […], with increasing sodium intake.'

• 'Higher sodium intake was associated with higher risk of […] fatal coronary heart disease.'
• 'There was no association between sodium intake and […] non-fatal coronary heart disease.'
• 'High and moderate-quality evidence that consuming <2 g sodium/day compared with consuming ≥2 g sodium/day is beneficial for reducing […] risk of […] coronary heart disease in adults.'

Stroke

• 'The evidence for adverse cardiovascular effects of sodium […] indicate an association of increased risk of morbidity and mortality from cardiovascular diseases, including […] stroke, with increasing sodium intake.'

• 'Higher sodium intake was associated with higher risk of incident stroke [and] fatal stroke'
• 'High and moderate-quality evidence that consuming <2 g sodium/ day compared with consuming ≥2 g sodium/day is beneficial for reducing […] risk of […] stroke […] in adults.'

• '… sodium intake is positively associated with an increased risk of stroke and cardiovascular events and mortality among the general adult population.'

• Low strength evidence that 'higher dietary sodium intake is associated with a greater risk for fatal and nonfatal stroke.'

Blood pressure and hypertension

• '… strong evidence of a dose response relationship between increased consumption of sodium as sodium chloride and higher levels of systolic, diastolic and mean blood pressure'
• 'The major adverse effect of increased sodium intake is elevated blood pressure.'

• 'Reducing sodium intake significantly reduced systolic and diastolic blood pressure in adults and children.'
• 'Reducing sodium intake to <2 g/day was more beneficial for blood pressure than reducing sodium intake but still consuming >2 g/day.'

• 'There is convincing evidence of a causal link between high salt intake and hypertension and of the benefit of reducing salt intake at population level.'

• 'There is clear evidence that high salt intake increases the risk of suboptimal blood pressure values and hypertension.'

• 'There is a progressive dose-response relationship between sodium intake and blood pressure.'
• '… lower sodium intake will attenuate the usual age-related increase in blood pressure.'
• '… reduction of sodium decreases blood pressure and […] the effect is greater among hypertensive subjects.'

• High strength evidence that reducing sodium intake lowers blood pressure in adults.

• Strong evidence that sodium reduction is beneficial to maintaining a normal blood pressure and can lower blood pressure in hypertensive individuals.
• Adoption of the Dietary Approaches to Stop Hypertension (DASH) dietary pattern is effective in lowering blood pressure.

Serum lipids

• High-quality evidence that 'reducing sodium intake had no significant adverse effect on […] blood lipids.'

Effect of salt/ sodium intake on cancer

• 'Consumption of foods preserved by salting is probably a cause of stomach cancer'.

• '… there is probable evidence for an association between salt intake and the risk of stomach cancer.'

Effect of salt/ sodium intake on renal function

• 'Moderate-quality evidence that reduced sodium is consistent with a benefit to renal function in adults.'
• High-quality evidence that 'Reducing sodium intake had no significant adverse effect on […] renal function.'

• 'Several studies have indicated a positive relationship between sodium excretion and calcium excretion'. High intake of sodium might increase the risk of kidney stones.

Effect of salt/ sodium intake on bone health

• 'Several studies have indicated a positive relationship between sodium excretion and calcium excretion and that sodium intake might play a role in the aetiology of osteoporosis.'

Other health effect of salt/ sodium intake

• High-quality evidence that 'decreasing sodium has no harmful effect on catecholamine levels or any minor side effects (e.g. headache and dizziness) in adults.'

• 'The available data are not sufficient to establish an upper level for sodium from dietary sources.'
• 'It is not possible to determine a threshold level of habitual sodium consumption below which there is unlikely to be any adverse effect on blood pressure.'

• A reduction to <2 g/day sodium (5 g/day salt) in adults (≥16 years of age) (strong recommendation).

• Public health goals: 'Population average consumption of salt from all sources to be less than 5 g (2 g of sodium) a day'
• Personal recommendations: 'Limit consumption of processed foods with added salt to ensure an intake of less than 6 g (2.4 g sodium) a day'
• Avoid salt-preserved, salted, or salty foods; preserve foods without using salt (instead use refrigeration, freezing, drying, bottling, canning, and fermentation).

• '… for reducing salt consumption […] target for the adult Irish population is a mean intake of 2.4 g/100 mmol sodium (6 g salt) per day. Whilst this is considered to be an achievable goal for the population at this time, it should not be regarded as an optimal or ideal level of consumption.'
• '… advice targeted at individual adults should reflect the Recommended Dietary Allowance (RDA) for sodium of 1.6 g/70 mmol (4 g salt) per adult per day [which] is sufficient to meet the needs of 97.5% of the population.'

• 'The approximate value for salt intake is up to 6 g/day.'
• Adequate intake for adults is 1500 mg sodium per day.

• 'a limitation of sodium intake to about 2.4 g/d – corresponding to about 6 g salt (NaCl) – is feasible at the population level'
• 'There is a lack of evidence to suggest that sodium requirements during pregnancy and lactation differ significantly from that of non-pregnant women.'

• 'The salt intake should be reduced to between 3.5 and a maximum of 6 grams per day.'

• 'recommendation for a target salt intake of 6g/day (2.4g/100 mmol sodium) for the adult population', for those aged 15 years upwards.

• 'The goals for the general population are: less than 2,300 mg dietary sodium per day (or age-appropriate Dietary Reference Intake amount)'
• Strong evidence that 'adults who would benefit from blood pressure lowering should combine the DASH dietary pattern with lower sodium intake'.

• Adults who would benefit from lowering blood pressure should lower sodium intake, and 'consume no more than 2400 mg of sodium/d; further reduction of sodium intake to 1500 mg/d can result in even greater reduction in BP; even without achieving these goals, reducing sodium intake by at least 1000 mg/d lowers BP' and 'combine the DASH dietary pattern with lower sodium intake.'

• For adults, a tolerable upper intake level (UL) for sodium is 2.3 g (100 mmol)/day (5.8 g of salt).
• The adequate intake (AI) for sodium for young adults is 1.5 g (65 mmol)/day (3.8 g of salt).
• 'The AI for sodium for older adults and the elderly is somewhat less, based on lower energy intakes, and is set at 1.3 g (55 mmol)/day for men and women 50 through 70 years of age, and at 1.2 g (50 mmol)/day for those 71 years of age and older.'

• Most countries' food based dietary guidelines recommend limiting salt intake to 5 or 6 g per day. Some countries only recommend a limited salt intake but do not quantify this recommendation.

• The recommended maximum level for children (2–15 years of age) should be adjusted downward based on the energy requirements of children.
• 'The recommended intake level in children is lower than that of adults when children’s energy requirements are less than adults.'

• 'Salt intake in children needs to be proportionally lower than in adults (based on body weight).'

• Adequate intakes for sodium for children: 1 to under 4 years: 0.4 g/d; 4 to under 7 years: 0.5 g/d; 7 to under 10 years: 0.75 g/day; 10 to under 13 years: 1.1 g/d; 13 to under 15 years: 1.4 g/d; 15 to under 19 years: 1.5 g/d.

• 'The recommended sodium intake for children up to 10 years age is set to 0.2 g per MJ (0.5 g NaCl/MJ), which is based on the energy-adjusted recommended levels for adult women.'

• 'The sodium level contained in breast milk is adequate to maintain health for infants'.
• The population targets for average salt consumption for children are (in g/day): <1 for 0-6 months, 1 for 7-12 months, 2 for 1-3 yrs., 3 for 4-6 yrs., 5 for 7-10 yrs., 6 for 11-14 yrs.

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• Implement guidelines including salt criteria for foods served in institutions (schools, workplaces, hospitals, care facilities, and prisons).

• Legislation on composition of foods to reduce salt content of foods and beverages is recommended.

• Taxation on foods high in sodium 'may encourage consumers to reduce consumption and revenues generated could support health promotion efforts.'

• Promoting food reformulation should be among the first salt reduction actions to consider. Engage with the food industry, agree on progressively lower targets for salt levels in foods and meals, and set a time frame. Mandatory approaches using legislation or regulation are more effective than voluntary approaches, possibly more cost-effective as well.
• Successful voluntary reformulation programmes require strong government leadership, close collaboration with industry and publication of good monitoring data on the salt content.
• Besides engaging food industry, other options for supporting reformulation are taxing foods high in salt, implementing effective labelling and communication strategies.

• For effective reduction in salt intake, it is proposed to prioritise food categories contributing most to population salt intake. Food manufacturers should prioritise the products with largest market share and deliver salt reduction across the full range of products from economy to premium items.
• Salt content in products should be reduced progressively in order to allow consumers to adapt to the less salty taste and to ensure continuous progress.

• Encourage the food industry to reformulate products to lower sodium content.

• Reducing the salt content in processed foods such as bread, sausage and cheese is recommended.
• Gradual reduction of salt content allows consumers to adapt to the taste.

• Marketing foods high in salt to children should be restricted.
• WHO proposes a nutrient profile model for the European Region. If limits of salt content (g/100g) in different food categories are exceeded by a food product, its marketing to children should be restricted.

• 'Legislation restricting marketing aimed at children of foods that are high in […] salt […] (e.g. on TV, internet, social media and on food packages) is recommended.'

• Implement guidelines including salt criteria for foods served in institutions (schools, workplaces, hospitals, care facilities, and prisons).

• Legislation on composition of foods to reduce salt content of foods and beverages is recommended.

• Taxation on foods high in sodium 'may encourage consumers to reduce consumption and revenues generated could support health promotion efforts.'

• Raise awareness of major sources of salt and health risks associated with salt intake. When major source is discretionary salt, education should be targeted to consumers, cooks and caterers. When major source is from processed foods, the target audience should be food industry and policy-makers.
• Focus on the link between salt intake and health, how to interpret salt labelling, how to choose and prepare low-salt alternatives.
• Implement behaviour change programmes (education, communication) in community settings (schools, workplaces, hospitals, care facilities and prisons).
• Set clear and specific behavioural objectives and implement a mix of strategies to provide information.

• Implement public education campaigns to increase the awareness of the health effects of excess added sodium.

• 'Countries should introduce clear, interpretive and accurate front-of-pack labelling schemes that enable consumers to understand the salt content of foods quickly and easily.'
• Prevent misleading marketing by allowing health claims only on products that meet certain nutritional criteria, e.g. contain less salt.

• Improve, standardize and implement Nutrition Facts labels and Front of Package (FOP) labels to help consumers make informed food choices.

• 'Establish an effective surveillance system to measure, monitor and evaluate population salt consumption patterns and the major sources of salt in the diet' for finding the greatest regional weaknesses.
• To track the changes of reducing salt content in foods, it is important to collect salt content information either with surveys or by chemical analysis of foods.
• Design monitoring and evaluation plan with defined indicators and time frames. Objective and transparent reporting will encourage the stakeholders to deliver on their commitments.

• The common European Union Framework on voluntary national salt initiatives set a benchmark of a minimum of 16% salt reduction over 4 years (2008-2012) for all food products, also encompassing salt consumed in restaurants and catering. The reduction in salt content should be progressive.
• Examples of legislative approaches in EU countries: in Belgium maximum level of 2% salt on dry matter of bread (not applied to imported bread); in Portugal and Croatia maximum level of salt in bread is 1.4 g salt/100 g.

• Legislation on mandatory maximum levels of sodium in meat products, breads, soups, seasoning mixes, and tinned food, also applicable to salt levels in restaurant dishes. Producers and importers not meeting the requirements may be fined.

• Various European countries have school food policies that address salt reduction or restrict the use of salt (in food preparation and/or at the table), savoury snacks and marketing of products high in salt.
  • In France the regulation on nutritional quality of school meals includes restrictions on salt (Decree n° 2011-1227) ;
  • In Italy the National guidelines on nutritional quality of school meals focuses also on salt reduction (IMH 2010).
  • In Romania legislation sets maximum amounts for salt (1.5 g salt or 0.6 g sodium per 100 g) in food sold in schools and pre-schools  

• Products distributed under the school fruit, vegetables and milk scheme shall not contain added salt.

• Public Health Product Tax is applied on products high in salt, including salty snacks (>1 g/100 g), condiments (>5 g/100 g), and flavourings (>15 g/100g).

• The 'Salt List' aims to inspire producers to lower salt content in all products for the benefit of public health. The list, compiled by a working group under the Danish Salt Partnership (public-private partnership), consists of 15 target food categories and 77 subcategories, and is part of the Danish salt reduction strategy.

• Salt Reduction Programme initiated by the food safety authority aims to voluntarily reduce salt content in processed foods. Companies and trade associations register within the programme and report yearly on undertakings and achievements.

• Voluntary reduction of salt (by 25%) in meat products introduced by the largest meat industries, under the Strategic Plan for reducing the excessive intake of kitchen salt in Republic of Croatia, 2014 – 2019.

• Salt reduction strategy to reduce (≥10%) salt content in bread and other processed foods through voluntary agreements signed between the Ministry of Health and the main National Associations of Bakers and other associations of food Industry.

• An agreement (collaborative protocol) has been signed between the Health Ministry and the bread industry to further reduce salt content in bread to 1 g/100 g by 2021 as part of the national strategy to promote healthy diet (Diário da República) . The agreed approach is to reduce by 0.1g per year salt content per 100g of bread until 2020 (current legal limit is 1.4 g/100 g). To encourage this change, the Ministry of Health has developed a label of excellence that is awarded to the bakeries that are already adhering to the 1g/100g limit (SNS) .

• The UK salt reduction sets targets for industry to reduce the salt content. To date, there have been four sets of target published (2006, 2009, 2011 and 2014). The targets specify specific salt or sodium levels to be met in 80 food categories and subcategories, including various meat, cereal, bread, cheese pizza, sandwiches and snack products.
• '…businesses can say they have met the target(s) for an individual sub-category if 95% of products or volume sales meet the targets and if efforts have been made to reduce salt in the remaining 5% of products or volume sales to a minimum'.

• Mandatory and voluntary reformulation through 'Less Salt, More Life' initiative. Voluntary agreements negotiated and signed with food industry (food manufacturers and retailers).

• A salt reduction strategy engaged food industry to voluntarily reduce salt content in bread and cheese. One company produces 80% of bread and reduced 10% of the salt content of almost all products during first three months. The Ministry of Health emphasized educating companies on methods and benefits of salt reduction and the importance of private sector in population-wide salt reduction.

• Various mandatory (via legislation) or voluntary (via industry self-regulation) policies are in place in the EU to restrict food marketing of foods that are high in sugar, salt and fats to children; a major industry self-regulation effort is the EU Pledge.  See Food and Non-alcoholic Beverages Marketing to Children and Adolescents in this series.

• All television advertising for processed foods containing added salt must be accompanied by a message such as 'For your health, eat at least five fruits and vegetables per day' or 'For your health, avoid eating too many foods that are high in fat, sugar or salt'.

• Legislation on foods high in salt (>0.3 g/100 g or ml) including restrictions on advertising at children less than 16 years (e.g. not using gifts or other benefits to encourage purchase, not using characters familiar to children). For advertising foods high in salt, a warning 'High in sodium: avoid excessive consumption' must be used.

• Shop Healthy in New York City in the US works with communities aiming to increase access to healthy food especially in areas with high rates of obesity. Department of Health staff works with shop owners to sell more low-salt products.

• Regulation 1169/2011 on food information to consumers requires mandatory nutrition declaration for the amount of salt in g/100g.
• Regulation 1924/2006 on nutrition and health claims made on foods states that permitted claims for salt are low sodium/salt, very low sodium/salt, sodium-free or salt-free, reduced salt and no added salt. See paragraph 3 Labelling in the EU.

• Compulsory use of warning labels on high-salt food in all the food categories that substantially contribute to the salt intake. Thresholds for the label as percentage by weight are e.g. more than 1.1% of salt in bread, 2.0% in sausages, 2.2% in cold meat cuts, 2.0% in fish products, 1.4% in cheese, 1.2% in ready meals, 1.4% in breakfast cereals or crisp bread. Also applied to unpackaged foods, in which case the warning sign must be communicated at the point of purchase.

• Foods that exceed 400 mg/100 g or 100 mg/100 ml of sodium will have a front of package warning message stating 'HIGH IN SODIUM'.

• Health claims are not permitted on foods that contain, per reference amount customarily consumed or per labelling serving size (exceptions apply) more than a set amount of 'disqualifying nutrient levels'. Among these the sodium threshold is 480 mg.

• Chain restaurants in New York are required to put a warning label (salt shaker inside a triangle) on menus and menu boards if dishes contain 2,300 mg sodium or more. The meaning of the symbol must be presented conspicuously at the point of purchase.

• The Keyhole logo used in many northern countries is based on a nutrient profile model and aims to identify healthier packaged food choices within a food category, and to stimulate food manufacturers to reformulate and develop healthier products. Salt content is one of the nutrient criteria, and thresholds depend on the product category.

• Products in line with the salt targets issued by the Danish Veterinary and Food Administration and the Danish Salt Partnership are able to make statements such as 'in line with the Government recommended salt targets'.

• The French Nutriscore front-of-pack labelling scheme discourages high sodium contents by assigning negative points depending on the sodium content per 100 g of food product.

• The Traffic Light front of pack voluntary labelling scheme, proposed by the UK Food Standards Agency, aims to assist consumers in identifying healthier food choices. It uses colour coding related to low, medium or high content of selected nutrients in foods and drinks. For total salt content in foods, the thresholds are (per 100g): green/low: ≤0.3 g, medium/amber: >0.3 to ≤1.5 g, high/red: >1.5 g. For salt content in drinks, the thresholds are (per 100ml):  green/low: ≤0.3 g ,  medium/amber: >0.3 to ≤0.75 g , high/red: >0.75 g.

• 'The voluntary [Health Star Rating] system is a front-of-pack labelling system that rates the overall nutritional profile of packaged food and assigns it a rating from ½ a star to 5 stars. It provides a quick, easy, standard way to compare similar packaged foods. The more stars, the healthier the choice.'

• Voluntary menu labelling for fast food chain restaurants. Nutrients are displayed per portion and include salt.

• Most EU countries have national food based dietary guidelines that recommend limiting the intake of salt.

• One aim of the EU Framework for National Salt Initiatives is to raise public awareness. It supports reformulation of foods.

• The UK's Food Standards Agency (FSA) raised awareness of salt consumption and how to reduce it using websites, TV, posters and printed materials, articles in women's journals and newspapers. They ran a four-phase campaign by educating the people on health concerns, encouraging reading food labels and not consuming more than 6 g of salt per day, focusing on high salt content foods and choosing low-salt products instead.

MONITOR^a

• An aim of the EU Framework for National Salt Initiatives is to monitor activities on reformulation, public awareness, and salt intake.

• In Denmark, monitoring of consumer salt intake measurements were performed in 1999, 2006, 2010, 2014 and 2016/2017.  Recently, the Research Centre for Prevention and Health has developed and validated a method by which it is possible to estimate the salt intake in a Caucasian population using single spot urine. This method will be used to monitor the progress of the Danish strategy to reduce salt intake on a population level.

• As part of the national salt reduction programme industry was asked to gradually decrease sodium levels. The levels of sodium and potassium across ten categories of processed foods have been monitored to support the salt reduction programme and provide information about industry commitments.

• In Italy, periodic monitoring of daily average dietary intake of sodium, potassium and iodine per capita is being performed (by 24-hour urine collection) in representative samples of Italian population. This monitoring is also used for the evaluation of actions related to excessive salt intake reduction in the Italian National Program “Gaining Health” (Salute 2007) and National Prevention Plan 2014-2018 (Salute 2014) .

• Monitoring the salt content in foods and publishing the data to encourage the food industry to reformulate foods to contain less salt. The target levels for salt were set for different categories of food products, and they were revised and reset every two years.