Non-communicable disease (NCD) prevention strategies now prioritise four major risk factors: food, tobacco, alcohol and physical activity. Dietary salt intake remains much higher than recommended, increasing blood pressure, cardiovascular disease and stomach cancer. Substantial reductions in salt intake are therefore urgently needed. However, the debate continues about the most effective approaches. To inform future prevention programmes, we systematically reviewed the evidence on the effectiveness of possible salt reduction interventions. We further compared “downstream, agentic” approaches targeting individuals with “upstream, structural” policy-based population strategies.
We searched six electronic databases (CDSR, CRD, MEDLINE, SCI, SCOPUS and the Campbell Library) using a pre-piloted search strategy focussing on the effectiveness of population interventions to reduce salt intake. Retrieved papers were independently screened, appraised and graded for quality by two researchers. To facilitate comparisons between the interventions, the extracted data were categorised using nine stages along the agentic/structural continuum, from “downstream”: dietary counselling (for individuals, worksites or communities), through media campaigns, nutrition labelling, voluntary and mandatory reformulation, to the most “upstream” regulatory and fiscal interventions, and comprehensive strategies involving multiple components.
After screening 2,526 candidate papers, 70 were included in this systematic review (49 empirical studies and 21 modelling studies). Some papers described several interventions. Quality was variable. Multi-component strategies involving both upstream and downstream interventions, generally achieved the biggest reductions in salt consumption across an entire population, most notably 4g/day in Finland and Japan, 3g/day in Turkey and 1.3g/day recently in the UK. Mandatory reformulation alone could achieve a reduction of approximately 1.45g/day (three separate studies), followed by voluntary reformulation (-0.8g/day), school interventions (-0.7g/day), short term dietary advice (-0.6g/day) and nutrition labelling (-0.4g/day), but each with a wide range. Tax and community based counselling could, each typically reduce salt intake by 0.3g/day, whilst even smaller population benefits were derived from health education media campaigns (-0.1g/day). Worksite interventions achieved an increase in intake (+0.5g/day), however, with a very wide range. Long term dietary advice could achieve a -2g/day reduction under optimal research trial conditions; however, smaller reductions might be anticipated in unselected individuals.
Comprehensive strategies involving multiple components (reformulation, food labelling and media campaigns) and “upstream” population-wide policies such as mandatory reformulation generally appear to achieve larger reductions in population-wide salt consumption than “downstream”, individually focussed interventions. This ‘effectiveness hierarchy’ might deserve greater emphasis in future NCD prevention strategies.
Citation: Hyseni L, Elliot-Green A, Lloyd-Williams F, Kypridemos C, O’Flaherty M, McGill R, et al. (2017) Systematic review of dietary salt reduction policies: Evidence for an effectiveness hierarchy? PLoS ONE 12(5): e0177535. https://doi.org/10.1371/journal.pone.0177535
Editor: Bhavani Shankar, SOAS, University of London, UNITED KINGDOM
Received: July 18, 2016; Accepted: April 29, 2017; Published: May 18, 2017
Copyright: © 2017 Hyseni et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the paper and its Supporting Information files.
Funding: Lirije Hyseni, Rory McGill and Lois Orton were funded by LiLaC/NIHR. This article presents independent research funded by the National Institute for Health Research’s School for Public Health Research (NIHR SPHR). The School for Public Health Research (SPHR) is funded by the National Institute for Health Research (NIHR). SPHR is a partnership between the Universities of Sheffield, Bristol, Cambridge, Exeter, UCL; The London School for Hygiene and Tropical Medicine; the LiLaC collaboration between the Universities of Liverpool and Lancaster and Fuse; The Centre for Translational Research in Public Health. The work was carried out under the remit of the WHO Collaborating Centre for Nutrition of the University of Warwick. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, the Department of Health or the World Health Organization. All other authors were funded by HEFCE. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
Non-communicable diseases (NCDs) kill over 35 million people annually. Common cancers, cardiovascular diseases, diabetes, respiratory diseases and dementia together now account for over two thirds of the entire global burden of disability and death.[1,2] These NCDs are mainly attributable to just four major risk factors. Furthermore, the contribution from poor diet exceeds the combined contribution from alcohol, tobacco and physical inactivity. This poor diet mainly reflects a predominantly unhealthy global food environment, dominated by processed foods high in sugar, saturated fat, trans-fat and, crucially, salt.
In the UK and other high income countries, over 70% of dietary salt is consumed in processed foods such as bread, breakfast cereals, processed meats, snack foods, soups and sauces.[4–6] This food environment contributes to excessive salt intake among adults, on average 10g/day or more, far in excess of what the body actually needs. High salt intake is a major risk factor for increasing blood pressure,[9–11] cardiovascular disease,[12–14] stroke,[15,16] and stomach cancer.[17–19] Moreover, a reduction in salt intake would substantially reduce this risk.
WHO recommends a maximum adult salt intake of 5g/day. Different strategies and policy options have been proposed to achieve this goal. Individual level interventions often involve behavioural approaches, for example dietary counselling, leaflets or medical advice. These are sometimes termed “downstream” or “agentic” interventions, and are dependent on the individual responding. [21,22] Conversely, “upstream” structural interventions take place at the population level and typically involve policies such as regulatory approaches, taxes or subsidies. Finally, intermediate interventions target subgroups in worksites, schools or communities.
National salt reduction strategies were identified in 75 countries in 2015, a substantial increase from 32 in 2010. However, the debate regarding the most effective and acceptable salt reduction strategy continues.
Notable policy approaches have been seen in Finland, Japan, and more recently, the United Kingdom. In the UK, a combination of awareness campaigns, agreed target settings, voluntary reformulation from industry and population monitoring of salt consumption have led to a 1.4g per day reduction in population salt intake between 2001 and 2011 (the campaign started in 2003). However, health inequalities in salt consumption have persisted.[28,29] Furthermore, the introduction of the UK Responsibility Deal in 2010 shifted emphasis to ‘downstream’ interventions, coupled with ineffective voluntary agreements and, controversially, the direct involvement of the industry in policy decisions.[30,31]
Geoffrey Rose famously advocated population wide approaches rather than targeting high-risk individuals. Furthermore, there seems to be some evidence for a public health ‘effectiveness hierarchy’ whereby “upstream” structural interventions consistently achieve larger improvements in population health, are more equitable and often reduce health inequalities[33,34] compared to “downstream” agentic interventions targeting individuals, for instance in tobacco control and alcohol policies.[35,36] Emerging evidence suggests that a comparable effectiveness hierarchy might also exist for salt reduction strategies, whereby upstream interventions apparently achieve bigger reductions in salt intake.[37,38]. To test this hypothesis and hence inform future preventive health strategies, we have systematically reviewed the evidence for studies focusing on the effectiveness of salt interventions to reduce salt intake.
We conducted a systematic review of interventions intended to decrease population dietary salt intake. To ensure proper conduct, we adhered to the PRISMA checklist (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)(S1 Table). We used a narrative synthesis and formally investigated evidence to support or refute an effectiveness hierarchy. The research protocol can be found in S1 File.
We first identified exemplar studies to define and refine search terms needed for targeted searches. The search strategy consisted of a combination of four sets of key words:
1) salt, sodium; 2) health promotion, nutrition education, campaigns, dietary counselling, regulation, legislation, tax, self-regulation, reformulation, social marketing, promotion, provision, labelling, marketing control, primary care advice, food industry; 3) public policy, health policy, nutrition policy, policies, interventions, strategies, initiatives, programmes, policy option, actions; and 4) effectiveness, effect, intake, consumption, reduction, cost-benefit analysis, and cardiovascular diseases.
A pilot search was conducted to determine appropriate databases, identify relevant studies and highlight potential issues to be addressed. This process identified six databases which were then used for the targeted searches: Ovid MEDLINE, Science Citation Index, SCOPUS, Cochrane Database of Systematic Reviews, The Campbell Collaboration Library of Systematic Reviews and the CRD Wider Public Health database. We searched for all studies published in the last four decades (from 1975 onwards). The final searches were conducted on 30 October 2015. All papers identified by the searches were imported into the Zotero data management programme to identify duplicates and help screen titles, abstracts and full texts as appropriate. The reference lists of included studies were scanned for potential additional papers and topic experts (FPC and SC) were also consulted for additional data sources.[40,41]
Study selection and inclusion criteria
Studies were included if they investigated the effectiveness of specific interventions on population dietary salt intake and contained quantitative outcomes. Only studies in English were included. We included a wide range of study designs including meta-analyses, trials, observational studies and natural experiments. Empirical studies and modelling studies were analysed separately, in view of their profound differences. The retrieved studies were assessed using the PICOS approach (Participants, Interventions, Comparators, Outcomes and Study design), summarised in Table 1. The primary outcome was salt intake (g/day). Studies reporting urinary sodium excretion (mmol/day) or sodium mg/day were converted to g/day. Where necessary, we simultaneously considered studies reporting solely on salt intake data in a specific population with the corresponding studies describing the interventions during that same time period.
One reviewer (LH) conducted the searches; extracted potential papers and removed duplicates. Two reviewers (LH and AEG) then independently screened titles and abstracts for eligibility using the inclusion and exclusion criteria. Full text was retrieved for all papers deemed potentially eligible and these were also screened independently by the two reviewers. Any discrepancies were resolved by consensus or by involving the senior author (SC).
Data extraction and management
Pre-designed and pre-piloted tables were used to extract data from all included studies. To ensure that all relevant information was captured, extracted data included: first author; year of publication; funder(s); study aim(s); sample size; study design; methods; participants; policies analysed; geographical scope; length of follow-up; outcomes, effect and response; authors’ assessment of limitations and our own assessment of potential risk of bias. The sources referenced for the effect sizes used in each modelling study were also specified in the tables (recognising that some modelling studies are based on empirical studies, potentially some included in this review). This data extraction was done independently by two reviewers (LH and AEG).
Quality assessment of included studies
Two reviewers (LH and AEG) independently assessed the methodological quality of each study (poor, fair or good). We used the National Heart, Lung and Blood Institute (NHLBI) tools specific for each research design (i.e. RCTs, cross-sectional studies, before and after studies, and systematic reviews). Several questions were asked for each study design (varying from 8 to 14) and depending on the points scored, the studies were labelled as good, fair or poor. However, we also took into consideration as to which questions points were allocated. For example, if an RCT scored 10 out of 14 points, but did not conduct an intention to treat analysis, it would be rated as fair rather than good. Modelling studies were independently assessed by two modelling experts (MOF & CK) using a different tool adapted from Fattore et al. (2014). Discrepancies in quality assessment were reconciled by consensus or by involving a third, senior member of the team (SC or HB).
Data synthesis and effectiveness hierarchy continuum
The evidence was summarised as a narrative synthesis according to intervention type, ranging from downstream to upstream interventions, to facilitate comparisons between the interventions. Summary tables of the studies included in this review can be found in Tables 2–10 for empirical studies and Table 11 for modelling studies. A more detailed data extraction of these studies can be found in S2 Table. We defined UPSTREAM interventions as those targeting the entire population (not a subset, however large) and creating structural changes (effectively removing individual choice from the equation). This accorded with the Nuffield’s ladder taxonomy, and with McLaren’s structural/agentic continuum. Conversely, we defined DOWNSTREAM interventions as those where the principal mechanism of action is “agentic”, being dependent on an individual altering their behaviour.
Interventions were then categorised according to their position in the McLaren et al. (2010) continuum from “upstream” to “downstream” (Fig 1).
Multi-component interventions were considered separately.
The literature search identified 3336 potentially relevant papers. An additional 26 papers were identified through other sources, including reference lists and key informants. After removing 836 duplicates, 2526 publications were left to be screened by title and abstract, after which 134 full-text papers were assessed for eligibility. A total of 70 papers were finally included (49 empirical studies and 21 modelling studies, Fig 2). The interventions and their effect sizes are presented in Fig 3 (empirical studies) and Fig 4 (modelling studies).
Forest plot of the empirical studies that were included in this systematic review. Negative values of salt reduction are interpreted as reported increase in salt consumption. For most combined interventions the sample size and confidence intervals were not reported. NA denotes not applicable or not reported.
Forest plot of the modelling studies that were included in this systematic review. Because of the different modelling approaches in these studies, their uncertainty measures are not comparable. Therefore we do not plot them in this graph. Different scenarios were considered for different studies. NA denotes not applicable or not reported.
Dietary counselling–individual level (Table 2)
Nine empirical studies (two of good quality;[45–46] five of fair quality;[47–51] and two of poor quality [52–53]), and three modelling studies (all of good quality [54–56]) investigated the effect on salt intake of dietary counselling targeted at consenting individuals.
Two separate meta-analyses investigated the effect of dietary advice on salt intake. The first included eleven randomised controlled trials (RCTs) and found a 1.8g/day salt reduction after up to 18 months of dietary advice. The second meta-analysis included eight RCTs and reported an overall reduction in salt consumption of 2.8g/day at 12 months and 2g/day up to 60 months. The two meta-analyses overlapped in respect of only three studies.
One additional RCT found a statistically significant net reduction of 0.6g/day between the groups, whilst a second RCT found no effect between the control and intervention group.
All three modelling studies predicted that dietary advice is less effective in reducing the disease burden of high salt intake, only gaining 180–2,600 quality-adjusted life years (QALYs) compared to other interventions (7,900–195,000 QALYs).[54–56]
Dietary counselling–school based and worksite interventions (Table 3)
Three school-based interventions (one of good quality; one of fair quality; one of poor quality ) and three worksite-based studies (all of fair quality) were included.[59–61] No modelling studies were identified for this section.
A nutrition programme in schools aimed at distinguishing between healthy and less healthy choices reported a non-significant reduction. In the second school based RCT, the practical intervention group achieved a significant net reduction of 0.7g/day compared with the control group. In a cluster RCT in China, education and training significantly reduced salt intake by a mean of −1.9 g/day in 279 school children (and −2.9 g/day in adult family members).
A randomised trial of a chronic disease prevention programme achieved a net reduction of 1.2g/day between the intervention and control group (P = 0.01). A factory-based intervention study in China assessed health education aimed at altering diet, together with a high-risk strategy of hypertension control. Salt intake was reduced by 3.9g/day from a mean of 16g/day (P<0.05).
Dietary counselling–community level (Table 4)
Four empirical studies and one review, all of fair quality,[62–66] investigated community based dietary counselling. One study reported a statistically significant difference of -0.4g/day in salt intake between the intervention and control groups. Two intervention trials of nutrition education reported significant reductions of 0.7g/day and 2.2g/day reductions respectively in salt intake after 12 months.[63–64] One RCT reported a favourable trend; however, this was non-significant and could have been caused by contamination between the groups.
Mass media campaigns (Table 5)
One empirical study of fair quality  and five modelling studies; four of good quality[56, 68–70] and one of fair quality were included.
The UK FSA salt reduction programme involved media campaigns to discourage table salt use, plus sustained pressure on industry to reformulate. Although salt consumption declined by 0.9g/day using spot urinary sodium readings from 2003–2007, the media contribution was unclear but likely modest.
The modelling studies likewise suggested media campaigns were generally considered less effective than food labelling or reformulation.[56, 69–71] The Change4Life campaign in the UK was predicted to reduce salt intake by 0.16g/day, less than labelling or reformulation. Gillespie et al. (2015) similarly estimated that social marketing might modestly reduce salt consumption by 0.03g/day to 0.13g/day.
Nutrition labelling (Table 6)
Two empirical studies, both of poor quality, investigated the effect of nutrition labelling on salt intake [72–73]. Reduced salt intake was not observed in participants who reported frequent vs. non-frequent label use (7.7g/day vs. 7.6g/day).
Ten modelling studies also examined labelling, four of good quality[56,68–70] and two of fair quality.[71, 74–77] These suggested that labelling might modestly reduce UK salt intake by 0.03g/day to 0.16g/day [68, 69]; much less than the 0.9g/day estimated by Roodenburg et al. (2013). Another study suggested that salt intake might be lowered by 1.2g/day if the population were to choose products labelled as low-salt, or increased by 1.6g/day if they choose products labelled as high salt content.
Reformulation (Table 7)
Very few studies which focused on reformulation included quantified results of salt intake. In one empirical Taiwanese study of fair quality, salt was enriched with potassium in the intervention group and their outcomes were an apparent reduction in cardiovascular deaths by 41%, compared to the control group rather than salt intake. Furthermore, people in the intervention group lived 0.3–0.9 years longer.
Fourteen modelling studies evaluated reformulation, eleven of good quality[41, 54–56, 68–70, 79–82] and three of fair quality[71, 83, 84]. Mandatory reformulation could consistently achieve bigger salt reductions than voluntary reformulation; 1.6g/day compared with 1.2g/day; and 1.4g/day versus 0.5g/day. Mandatory reformulation might also achieve higher reductions in disability-adjusted life years (DALYs) and QALYs compared to voluntary reformulation.[54, 56, 79]
In the Netherlands, reformulation of processed foods was predicted to reduce median salt intake by 2.3g/day, compared with a 0.9g/day from a two-year salt reformulation initiative in Argentina.
Fiscal interventions (Table 8)
Two systematic reviews of fair quality [85, 86] included three modelling studies eligible for this review. Furthermore, three additional tax modelling studies were included, all of good quality.[56, 81, 87] Two studies included in Niebylski et al’s. systematic review (2015) modelled a 1% tax on salty snacks or on cheese and butter; neither reduced salt consumption. Another modelling study suggested that a very high (40%) tax might achieve a 6% reduction in salt consumption (0.6g/day).
One modelling study predicted that a 20% tax on major dietary sodium sources might prevent or postpone 2000 deaths annually, whilst Nghiem et al. (2015) predicted that a sodium tax might gain more QALYs than other interventions.
Multi-component interventions (Table 9 and Table 10)
Fifteen papers were included under multi-component interventions. Most studies came from Japan, Finland and the UK. Two were of good quality;[88, 89] ten of fair quality;[24, 43, 89–96] and four of poor quality.[97–100]
Four studies were included which presented dietary salt intake and linked to papers describing the interventions; (one of good quality;; two of fair quality;[101, 102] and one of poor quality.
The Japanese government initiated a sustained campaign in the 1960s. Over the following decade, mean salt intake fell from 13.5g/day to 12.1g/day overall (and from 18g/day to 14g/day in Northern Japan). Miura et al. (2000) reported that salt intake subsequently decreased from 14.5g/day in 1972 to 10.6g/day in 2010, a fall of almost 4g/day . Stroke mortality was predicted to fall by 80%.[90, 93]
Starting in 1978, Finland pursued a comprehensive salt reduction strategy using mass media campaigns, mandatory labelling and voluntary reformulation by the food industry. Population salt consumption was monitored regularly by using 24h urinary assessment and dietary survey data. By 2007, salt intake had reduced by approximately 4g/day, from 13 to 8.3g/day in men, and from 11 to 7g/day in women.[24, 25] Stroke and coronary heart disease (CHD) mortality fell by over 75% during that period.
The UK salt reduction strategy included voluntary reformulation, a consumer awareness campaign, food labelling, target settings and population monitoring. By 2011, population salt intake, measured by 24h urinary sodium excretion, had decreased by 1.4g/day (9.5g/day to 8.1g/day). He et al. (2014b) estimated that this might reduce stroke and coronary heart disease mortality by some 36%.
Other countries have implemented several strategies including labelling, media campaigns and voluntary reformulation and effect sizes ranged from -0.4g/day in France [24, 93] to -4.8g/day in China [24, 102].
Modelling studies of combined interventions.
Six modelling studies investigated the effect of multi-component interventions, three were of good quality;[70, 104, 105] whilst three others were of fair quality.[70, 106, 107]
Several modelling studies consistently suggested that multi-component salt reduction strategies (e.g. labelling, health promotion and reformulation) would be more effective than any single intervention.[70, 71] For instance, Gase et al. (2011) suggested that using labelling, promotion, subsidies and provision of low sodium options could lead to a 0.7–1.8g/day reduction.
This systematic review of salt reduction interventions suggests that comprehensive strategies could generally achieve the biggest reductions in salt consumption across an entire population, approximately 4g/day in Finland and Japan, 3g/day in Turkey and 1.3g/day recently in the UK. Mandatory reformulation alone could achieve a reduction of approximately 1.4g/day, followed by voluntary reformulation (median 0.7g/day) school interventions (0.7g/day) and worksite interventions (+0.5g/day). Smaller population benefits were generally achieved by short-term dietary advice (0.6g/day), community-based counselling (0.3g/day), nutrition labelling (0.4g/day), and health education media campaigns (-0.1g/day). Although dietary advice to individuals achieved a -2g/day reduction, this required optimal research trial conditions (smaller reductions might be anticipated in unselected individuals).
Comparison with other research
Geoffrey Rose famously argued that a greater net benefit came from the population-wide approach, (achieving a small effect in a large number of people) when compared with targeting high risk individuals (a large effect but only achieved in a small number of people).
Multi-component salt reduction strategies involving a series of structural initiatives together with campaigns to increase population awareness have been successful in Japan and Finland where they substantially reduced dietary salt consumption, and associated high stroke and cardiovascular disease mortality rates. In Finland, some credit should also go to other dietary changes e.g. fat quality.
Between 2003 and 2010, a multi-component approach in the UK including voluntary reformulation and political pressure on industry to agree category-specific targets achieved some success (1.3g/day reduction in population salt consumption over 8 years to 8.1g/day in 2011). Interestingly, pre-existing health inequalities in salt consumption persisted. However, from 2010, the Responsibility Deal simply advocated a voluntary scheme. This was ineffective, and MacGregor therefore subsequently recommended mandatory reformulation. Other useful reductions were demonstrated in other countries mostly using dietary surveys and some from grey literature. However, the -4.8g/day reduction reported in China appears extra-ordinarily large and perhaps merits some caution . Multi-component interventions clearly have more potential than single interventions, and synergies might be anticipated. [13,93] Similarly powerful benefits have also been observed with comprehensive strategies for tobacco control and alcohol reduction.[35,36]
In high income countries, the majority of dietary salt intake comes in processed food (75%) and reformulation can be very effective in reducing salt consumption. Though mandatory reformulation is more powerful, most countries currently use voluntary reformulation.[54,56,68,69,110] Success may then be very dependent on the degree of political pressure applied to the food industry and on regular, independent monitoring, as recently achieved in the UK. [111,112]
Nutrition labelling can be potentially effective, as demonstrated in Finland  and Brazil. Nutrition labelling allows consumers to make informed choices whilst also putting pressure on the food industry to reformulate. However, interpretation of labels depends on health literacy and different labelling systems may confuse consumers, and reinforce inequalities.. Consumers generally want simple (traffic light) labels which are easier to understand.[76,77,113,114]
Dietary interventions in diverse settings: communities, worksites, schools and homes.
Dietary interventions can be delivered at different levels, such as communities, worksites, schools or to individuals. However, effectiveness varies widely.[45,47,50] Furthermore, the benefits of dietary counselling decrease over time and are thus generally not sustainable; much smaller reductions might therefore be anticipated in unselected individuals in the general population. Furthermore, for many individuals, issues such as competing priorities and financial constraints might reduce compliance and adherence,[8,13,21,22] and thus reduce net population benefits.
Mass media campaigns.
Few empirical studies have examined salt media campaigns. However, benefits appear to be generally modest.[56, 67,68,69,115] or negligible. Many individuals may not perceive any personal relevance and hence fail to engage in any behaviour change.[22,116,117]
Public health benefits and cost-effectiveness
Most economic analyses have consistently predicted substantial reductions in cardiovascular mortality, and consequent gains in life-years, QALYs, DALYs and healthcare savings. This is consistent with the growing evidence that population-wide prevention policies can often be powerful, rapid, equitable and cost-saving.[38,119–122]
Several modelling studies also investigated the cost-effectiveness of the salt interventions described above. Mandatory and voluntary reformulation appeared far more cost-effective than labelling or [54,55,68] dietary advice targeting individuals.
Strengths and limitations
This systematic review has multiple strengths. Firstly, two independent reviewers screened all papers and assessed quality using appropriate validated tools. Secondly, the inclusion of modelling studies (presented separately) adds value by allowing the evaluation of certain interventions where empirical studies failed (e.g. labelling). In addition, we recorded the effect size used in each modelling paper together with the source reference. Furthermore, most of the better quality modelling studies confirmed the superiority of upstream approaches. Finally, the studies reviewed included a wide variety of interventions, thus providing a useful spread of estimates.
Our review also has limitations. We were unable to conduct a formal meta-analysis due to the profound heterogeneity of the diverse studies, many of which included multiple interventions. Furthermore, studies were only included if the full text was available in English (15 non-English papers were excluded). We also had to exclude two potentially relevant studies which lacked the full text.[123,124] Publication bias remains possible, potentially over-estimating the true effect of some interventions. The primary outcome of this study was dietary intake (consumption); we excluded studies considering other dietary behaviours such as awareness, knowledge, preferences or purchasing behaviour. Also, the positive benefits of policy changes may sometimes appear larger if favourable underlying secular trends have not been formally considered. Furthermore, we did not contact authors for missing data. However, all the key information was presented in all but two papers. [123,124] Finally, generalization of the results should be cautioned as countries may vary in baseline salt intake.
More deprived groups more often consume foods high in salt, (and sugar and fat); all are associated with poor health.[125–127] These inequalities persist in Britain [28,29] and Italy.
Downstream interventions focused on individuals typically widen inequalities whereas upstream “structural” interventions may reduce inequalities.[33,129,130]
This review highlights the greater power of combined (multi-component) strategies, mandatory reformulation and traffic light labelling. Most were cost-effective and many were cost-saving. However, the feasibility of implementing policy changes also deserves further study. Many factors can facilitate or obstruct successful policy development, notably including political feasibility and stakeholder influence.[114,131,132]
Stoeckle and Zola’s “upstream”/”downstream” concept was disseminated by John McKinlay, critiqued by Krieger, and then refined as a structural/agentic continuum by McLaren et al 2010. To test our effectiveness hierarchy hypothesis, one ideally needs to quantify the “average” effect of each category of salt reduction intervention. Yet, the limited number and heterogeneity of these studies precludes a formal meta-analysis. However, the consistency with the effectiveness hierarchies demonstrated by tobacco and alcohol control interventions is encouraging. The effectiveness hierarchy hypothesis now clearly needs to be tested in other fields.
There are clear implications for public health. The biggest population-wide reductions in salt consumption were consistently achieved by comprehensive multi-component strategies involving “upstream” population-wide policies (regulation, mandatory reformulation, and food labelling).”Downstream” individually-based interventions appear relatively weak (e.g. dietary counselling to individuals and school children, and media campaigns in isolation).
This ‘effectiveness hierarchy’ might deserve greater emphasis on the agendas of the WHO and other global health organizations reviewing action plans for NCD prevention.
S1 Table. PRISMA checklist.
S2 Table. Full data extraction tables empirical and modelling studies.
S1 File. Research protocol.
We thank Mark Petticrew and Cecile Knai for their very helpful comments. FPC contributed under the remit of the Terms of Reference of the World Health Organization Collaborating Centre for Nutrition of the University of Warwick.
- Conceptualization: SC.
- Formal analysis: CK LH SC.
- Funding acquisition: SC.
- Investigation: LH AEG FLW RMG LO.
- Methodology: LH LO RMG SC.
- Project administration: LH.
- Supervision: SC LH.
- Validation: LH AEG.
- Visualization: CK LH.
- Writing – original draft: LH AEG FLW CK MOF RMG LO HB FPC SC.
- Writing – review & editing: LH AEG FLW CK MOF RMG LO HB FPC SC.
- 1. Lozano R, Naghavi M, Foreman K, Lim S, Shibuya K, Aboyans V, et al. Global and regional moratlity from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet. 2012;380(9859): 2095–128. pmid:23245604
Vos T, Barber RM, Bell B, Bertozzi-Villa A, Biryukov S, Bolligeret I, et al. Global, regional, and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013. In press, corrected proof.
- 3. Lim SS, Vos T, Flaxman AD, Danaei G, Shibuya K, Adair-Rohani H, et al. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010. The Lancet. 2012;380: 2224–2260.
- 4. Anderson CA, Appel LJ, Okuda N, Brown IJ, Chan Q, Zhao L, et al. Dietary Sources of Sodium in China, Japan, the United Kingdom, and the United States, Women and Men Aged 40 to 59 Years: The INTERMAP Study. J Am Diet Assoc. 2010;110(5): 736–45. pmid:20430135
- 5. Webster JL, Dunford EK, Neal BC. A systematic survey of the sodium contents of processed foods. Am J Clin Nutr. 2010;91(2): 413–420. pmid:19955402
- 6. Ni Mhurchu C, Capelin C, Dunford EK, Webster JL, Neal BC, Jebb SA. Sodium content of processed foods in the United Kingdom: analysis of 44,000 foods purchased by 21,000 households. Am J Clin Nutr. 2011;93(3): 594–600. pmid:21191142
World Health Organization. Salt reduction [online], WHO 2010. Available at: http://www.who.int/mediacentre/factsheets/fs393/en/
- 8. Cappuccio FP & Capewell S. Facts, Issues, and Controversies in Salt Reduction for the Prevention of Cardiovascular Disease. Functional Food Reviews. 2015;7: 41–61.
- 9. He FJ & MacGregor GA. Effect of modest salt reduction on blood pressure: a meta-analysis of randomized trials. Implications for public health. J Hum Hypertens. 2002;16: 761–770. pmid:12444537
- 10. Aburto NJ, Ziolkovska A, Hooper L, Elliott P, Cappuccio FP, Meerpohl JJ. Effect of lower sodium intake on health: systematic review and meta-analyses. BMJ. 2013;346: f1326. pmid:23558163
- 11. He FJ, Li J, MacGregor GA. Effect of longer term modest salt reduction on blood pressure: Cochrane systematic review and meta-analysis of randomised trials. BMJ. 2013;346: f1325. pmid:23558162
- 12. Cook NR, Cutler JA, Obarzanek E, Buring JE, Rexrode KM, Kumanyika SK, et al. Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP). BMJ. 2007;334: 885. pmid:17449506
- 13. He FJ & MacGregor GA. A comprehensive review on salt and health and current experience of worldwide salt reduction programmes. J Hum Hypertens. 2009;23(6): 363–84. pmid:19110538
- 14. Strazzullo P, D’Elia L, Kandala NB, Cappuccio FP. Salt intake, stroke, and cardiovascular disease: meta-analysis of prospective studies. BMJ. 2009;339: b4567. pmid:19934192
- 15. Perry IJ & Beevers DG. Salt intake and stroke: a possible direct effect. J Hum Hypertens. 1992; 6(1): 23–5. pmid:1583626
- 16. Karpannen H & Mervaala E. Sodium intake and hypertension. Prog Cardiovasc Dis. 2006;49(2): 59–75. pmid:17046432
- 17. Joossens JV, Hill MJ, Elliott P, Stamler R, Lesaffre E, Dyer A et al. Dietary salt, nitrate and stomach cancer mortality in 24 countries. European Cancer Prevention (ECP) and the INTERSALT Cooperative Research Group. Int J Epidemiol. 1996;25: 494–504. pmid:8671549
- 18. Wang X- Q, Terry PD, Yan H. Review of salt consumption and stomach cancer risk: Epidemiological and biological evidence. World J Gastroenterol. 2009;15(18): 2204–13. pmid:19437559
- 19. D'Elia L, Rossi G, Ippolito R, Cappuccio FP, Strazzullo P. Habitual salt intake and risk of gastric cancer: a meta-analysis of prospective studies. Clin Nutr. 2012;31: 489–98. pmid:22296873
WHO. Guideline: Sodium intake for adults and children. Geneva, World Health Organization (WHO),2012
- 21. McLaren L, McIntyre L & Kirkpatrick S. Rose’s population strategy of prevention need not increase social inequalities in health. Int J Epidemiology. 2010;39: 372–377.
- 22. Adams J, Mytton O, White M, Monsivais P. Why Are Some Population Interventions for Diet and Obesity More Equitable and Effective Than Others? The Role of Individual Agency. PLoS Med (2016); 13 (4): e1001990. pmid:27046234
- 23. Brownson RC, Seiler R, Eyler AA. Measuring the impact of public health policy. Prev Chronic Dis. 2010;7(4): A77. pmid:20550835
- 24. Trieu K, Neal B, Hawkes C, Dunford E, Campbell N, Rodriguez-Fernandez R, et al. Salt initiatives around the world–A systematic review of progress towards the global target. Plos One. 2015;10(7): e0130247 pmid:26201031
- 25. Laatikainen T, Pietinen P, Valsta L, Sundvall J, Reinivuo H, Tuomilehto J. Sodium in the Finnish diet: 20-year trends in urinary sodium excretion among the adult population. Eur J Clin Nutr. 2006;60(8): 965–70. pmid:16482074
Sasaki N. The salt factor in apoplexy and hypertension: epidemiological studies in Japan. In: Yamori Y, editor. Prophylactic approach to hypertensive diseases. New York: Raven Press; 1979. p. 467–74.
- 27. He FJ, Pombo-Rodrigues S, Macgregor GA. Salt reduction in England from 2003 to 2011: its relationship to blood pressure, stroke and ischaemic heart disease mortality. BMJ Open. 2014a;4(4): e004549.
- 28. Ji C, Kandala N- B & Cappuccio FP. Spatial variation of salt intake in Britain and association with socio-economic status. BMJ Open. 2013;3: e002246. pmid:23295624
- 29. Ji C & Cappuccio FP. Socio-economic inequality in salt intake in Britain 10 years after a national salt reduction programme. BMJ Open. 2014;4: e005683. pmid:25161292
- 30. Knai C, Petticrew M, Durand MA, Eastmure E, James L, Mehrotra A, et al. Has a public–private partnership resulted in action on healthier diets in England? An analysis of the Public Health Responsibility Deal food pledges. Food Policy. 2015;54: 1–10.
- 31. MacGregor GA, He FJ, Pombo-Rodrigues S. Food and the responsibility deal: how the salt reduction strategy was derailed by Andrew Lansley and the coalition government. Br Med J. 2015;350: h1936.
- 32. Rose G. Sick individuals and sick populations. International Journal of Epidemiology. 2001;30:427–432 pmid:11416056
- 33. Capewell S & Graham H. Will cardiovascular disease prevention widen health inequalities? PLoS Med. 2010;7(8): e1000320. pmid:20811492
- 34. Hogberg L, Cnattingius S, Lundholm C, Sparén P, Iliadou AN. Intergenerational social mobility and the risk of hypertension. J Epidemiol Community Health. 2012;66(6): e9. pmid:21747130
- 35. Joossens L & Raw M. The Tobacco Control Scale: a new scale to measure country activity. Tob Control. 2006;15: 247–253. pmid:16728757
- 36. Anderson P, Chisholm D, Fuhr DC. Alcohol and Global Health 2. Effectiveness and cost-effectiveness of policies and programmes to reduce the harm caused by alcohol. Lancet. 2009;373: 2234–46. pmid:19560605
- 37. Cappuccio FP, Capewell S, Lincoln P, McPherson K. Population salt reduction to prevent cardiovascular disease: identifying policy options. BMJ. 2011;343: d4995. pmid:21835876
NICE Public Health Guidance: Prevention of cardiovascular disease at population level. 2010. Reviewed and updated in 2014: http://guidance.nice.org.uk/PH25/Review
- 39. Moher D, Liberati A, Tetzlaff J, Altman DG, PRISMA Group. Preferred reporting items for the systematic reviews and meta-analysis: the PRISMA statement. BMJ. 2009;339: b2535. pmid:19622551
- 40. He FJ, Wu Y, Feng X- X, Ma J, Ma Y, Wang H, et al. School based education programme to reduce salt intake in children and their families (School-EduSalt): cluster randomised controlled trial. BMJ. 2015;350: h770. pmid:25788018
- 41. Choi SE, Brandeau ML, Basu S. Expansion of the National Salt Reduction Initiative: A Mathematical Model of Benefits and Risks of Population-Level Sodium Reduction. Medical Decision Making 2015.
National institute of Health. Quality assessment tools. 2014. Accessed from https://www.nhlbi.nih.gov/health-pro/guidelines/in-develop/cardiovascular-risk-reduction/tools
- 43. Fattore G, Ferre F, Meregaglia M, Fattore E, Agostoni C. Critical review of economic evaluation studies of interventions promoting low-fat diets. Nutr Rev. 2014;72(11): 691–706. pmid:25323698
Nuffield Council on Bioethics. Policy process and practice. In: Public Health: Ethical issues. London, UK: Nuffield Council on Bioethics. 2007: 31–47.
- 45. Hooper L, Bartlett C, Davey Smith G, Ebrahim S. Systematic review of long term effects of advice to reduce dietary salt in adults. BMJ. 2002;325(7365): 628. pmid:12242173
- 46. Appel LJ. Effects of Comprehensive Lifestyle Modification on Blood Pressure Control: Main Results of the PREMIER Clinical Trial. JAMA. 2003;289(16): 2083–93. pmid:12709466
- 47. Brunner E, White I, Thorogood M, Bristow A, Curle D, Marmot M. Can dietary interventions change diet and cardiovascular risk factors: a meta-analysis of randomized controlled trials. Am J Public Health. 1997;87(9): 1415–1422. pmid:9314790
- 48. Francis S, Taylor M. A social marketing theory-based diet-education program for women ages 54 to 83 years improved dietary status. J Am Diet Assoc. 2009;109(12): 2052–6. pmid:19942023
- 49. Parekh S, Vandelanotte C, King D, Boyle FM. Improving diet, physical activity and other lifestyle behaviours using computer-tailored advice in general practice: a randomised controlled trial. Int J Behav Nutr Phys Act. 2012;9: 108. pmid:22963354
- 50. Petersen K, Torpy D, Chapman I, Guha S, Clifton P, Turner K, et al. Food label education does not reduce sodium intake in people with type 2 diabetes mellitus. A randomised controlled trial. Appetite. 2013;68: 147–51. pmid:23665299
- 51. Kokanović A, Mandić ML, Banjari I. Does individual dietary intervention have any impact on adolescents with cardiovascular health risks? Medicinski Glasnik. 2014;11(1): 234–7. pmid:24496370
- 52. Heino T, Kallio K, Jokinen E, Lagström H, Seppänen R, Välimäki I, et al. Sodium intake of 1 to 5-year-old children: the STRIP project. The Special Turku Coronary Risk Factor Intervention Project. Acta paediatrica. 2000;89(4): 406–10. pmid:10830450
- 53. Wang J, Olendzki BC, Wedick NM, Persuitte GM, Culver AL, Li W, et al. Challenges in sodium intake reduction and meal consumption patterns among participants with metabolic syndrome in a dietary trial. Nutrition Journal. 2013, 12:163 pmid:24345027
- 54. Cobiac LJ, Vos T, Veerman JL. Cost-effectiveness of interventions to reduce dietary salt intake. Heart. 2010;96(23): 1920–5. pmid:21041840
- 55. Cobiac LJ, Magnus A, Lim S, Barendregt JJ, Carter R, Vos T. Which interventions offer best value for money in primary prevention of cardiovascular disease? PLoS One. 2012;7: e41842. pmid:22844529
- 56. Nghiem N, Blakely T, Cobiac LJ, Pearson AL, Wilson N. Health and economic impacts of eight different dietary salt reduction interventions. PLoS ONE. 2015;10(4): e0123915. pmid:25910259
- 57. Cotter J, Cotter MJ, Oliveira P, Cunha P, Polónia J. Salt intake in children 10–12 years old and its modification by active working practices in a school garden. J Hypertens. 2013;31(10): 1966–71. pmid:24107730
- 58. Katz DL, Katz CS, Treu JA, Reynolds J, Njike V, Walker J, et al. Teaching healthful food choices to elementary school students and their parents: the Nutrition DetectivesTM program. J Sch Health. 2011;81(1): 21–8. pmid:21158862
- 59. Aldana SG, Greenlaw RL, Diehl , Salberg A, Merrill RM, Ohmine S. The effects of a worksite Chronic disease prevention program. J Occup Environ Med. 2005;47: 558–564. pmid:15951715
- 60. Chen J, Wu X, Gu D. Hypertension and cardiovascular diseases intervention in the capital steel and iron company and Beijing Fangshan community. Obes Rev. 2008;9 Suppl 1:142–5.
- 61. Levin S, Ferdowsian H, Hoover V, Green AA, Barnard ND. A worksite programme significantly alters nutrient intakes. Public Health Nutr. 2010;13(10): 1629–35. pmid:20074388
- 62. Yanek LR, Becker DM, Moy TF, Gittelsohn J, Koffman DM. Project Joy: faith based cardiovascular health promotion for African American women. Public Health Rep. 2001;116 Suppl 1:68–81.
- 63. Cappuccio FP, Kerry SM, Micah FB, Plange-Rhule J, Eastwood JB. A community programme to reduce salt intake and blood pressure in Ghana [ISRCTN88789643]. BMC Public Health. 2006;6: 13. pmid:16433927
- 64. Takahashi Y, Sasaki S, Okubo S, Hayashi M, Tsugane S. Blood pressure change in a free-living population-based dietary modification study in Japan. J Hypertension. 2006;24(3): 451–8.
- 65. Robare JF, Milas NC, Bayles CM, Williams K, Newman AB, Lovalekar MT, et al. The key to life nutrition program: results from a community-based dietary sodium reduction trial. Public Health Nutr. 2010;13(5): 606–14. pmid:19781124
- 66. Van de Vijver S, Oti S, Addo J, de Graft-Aikins A, Agyemang C. Review of community-based interventions for prevention of cardiovascular diseases in low- and middle-income countries. Ethn Health. 2012;17(6): 651–76. pmid:23297746
- 67. Shankar B, Brambila-Macias J, Traill B, Mazzocchi M, Capacci S. An evaluation of the UK Food Standards Agency’s salt campaign. Health Econ. 2013;22(2): 243–50. pmid:22223605
- 68. Collins M, Mason H, O’Flaherty M, Guzman-Castillo M, Critchley J, Capewell S. An economic evaluation of salt reduction policies to reduce coronary heart disease in England: A policy modeling study. Value in Health. 2014;17(5): 517–24. pmid:25128044
- 69. Gillespie D, Allen K, Guzman-Castillo M, Bandosz P, Moreira P, McGill R et al. The health equity and effectiveness of policy options to reduce dietary salt intake in England: policy forecast. PLoS ONE. 2015;10(7): e0127927. pmid:26131981
- 70. Wilcox ML, Mason H, Fouad FM, Rastam S, al Ali R, Page TF, et al. Cost-effectiveness analysis of salt reduction policies to reduce coronary heart disease in Syria, 2010–2020. Int J Public Health. 2015;60: S23–30. pmid:24972676
- 71. Mason H, Shoaibi A, Ghandour R, O’Flaherty M, Capewell S, Khatib R, et al. A cost effectiveness analysis of salt reduction policies to reduce coronary heart disease in four Eastern Mediterranean countries. PLoS ONE. 2014;9(1): e84445. pmid:24409297
- 72. Babio N, Vicent P, López L, Benito A, Basulto J, Salas-Salvadó J. Adolescents’ ability to select healthy food using two different front-of-pack food labels: a cross-over study. Public Health Nutr. 2014;17(6): 1403–9. pmid:23680067
- 73. Elfassy T, Yi S, Eisenhower D, Lederer A, Curtis CJ. Use of sodium information on the nutrition facts label in New York city adults with hypertension. J Acad Nutr Diet. 2015;115(2): 278–83. pmid:25441962
- 74. Pietinen P, Valsta LM, Hirvonen T, Sinkko H. Labelling the salt content in foods: a useful tool in reducing sodium intake in Finland. Public Health Nutr. 2008;11(4): 335–40. pmid:17605838
- 75. Temme EHM, van der Voet H, Roodenburg AJC, Bulder A, van Donkersgoed G, van Klaveren J. Impact of foods with health logo on saturated fat, sodium and sugar intake of young Dutch adults. Public Health Nutr. 2011;14(4): 635–44. pmid:20843399
- 76. De Menezes EW, Lopes TDVC, Mazzini ER, Dan MCT, Godoy C, Giuntini EB. Application of Choices criteria in Brazil: Impact on nutrient intake and adequacy of food products in relation to compounds associated to the risk of non-transmissible chronic diseases. Food Chem. 2013;140(3): 547–52. pmid:23601405
- 77. Roodenburg AJC, van Ballegooijen AJ, Dötsch-Klerk M, van der Voet H, Seidell JC. Modelling of Usual Nutrient Intakes: Potential Impact of the Choices Programme on Nutrient Intakes in Young Dutch Adults. PLoS ONE. 2013;8(8): e72378. pmid:24015237
- 78. Chang HY, Hu YW, Yue CS, Wen YW, Yeh WT, Hsu LS, et al. Effect of potassium enriched salt on cardiovascular mortality and medical expenses of elderly men. Am J Clin Nutr. 2006;83: 1289–96. pmid:16762939
- 79. Murray CJ, Lauer JA, Hutubessy RC, Niessen L, Tomijima N, Rodgers A, et al. Effectiveness and costs of interventions to lower systolic blood pressure and cholesterol: a global and regional analysis on reduction of cardiovascular-disease risk. The Lancet. 2003;361(9359): 717–25.
- 80. Rubinstein A, Colantonio L, Bardach A, Caporale J, Martí SG, Kopitowski K, et al. Estimation of the burden of cardiovascular disease attributable to modifiable risk factors and cost-effectiveness analysis of preventative interventions to reduce this burden in Argentina. BMC Public Health. 2010;10: 627. pmid:20961456
- 81. Smith-Spangler CM, Juusola JL, Enns EA, Owens DK, Garber AM. Population strategies to decrease sodium intake and the burden of cardiovascular disease: A cost-effectiveness analysis. Ann Intern Med. 2010;152(8): 481–7. pmid:20194225
- 82. Konfino J, Mekonnen TA, Coxson PG, Ferrante D, Bibbins-Domingo K. Projected impact of a sodium consumption reduction initiative in Argentina: an analysis from the CVD policy model—Argentina. PLoS ONE. 2013;8(9): e73824. pmid:24040085
- 83. Rubinstein A, García Martí S, Souto A, Ferrante D, Augustovski F. Generalized cost-effectiveness analysis of a package of interventions to reduce cardiovascular disease in Buenos Aires, Argentina. Cost Eff Resour Alloc. 2009;7(1): 10.
- 84. Hendriksen MAH, Hoogenveen RT, Hoekstra J, Geleijnse JM, Boshuizen HC, van Raaij JMA. Potential effect of salt reduction in processed foods on health. Am J Clin Nutr. 2014;99(3): 446–53. pmid:24335058
- 85. Thow AM, Downs S, Jan S. A systematic review of the effectiveness of food taxes and subsidies to improve diets: understanding the recent evidence. Nutr Rev. 2014;72(9): 551–65. pmid:25091552
- 86. Niebylski ML, Redburn KA, Duhaney T, Campbell NR. Healthy food subsidies and unhealthy food taxation: A systematic review of the evidence. Nutrition. 2015;31(6): 787–95. pmid:25933484
- 87. Mhurchu CN, Eyles H, Genc M, Scarborough P, Rayner M, Mizdrak A, et al. Effects of health-related food taxes and subsidies on mortality from diet-related disease in New Zealand: An econometric-epidemiologic modelling study. PLoS ONE 2015;10(7): e0128477. pmid:26154289
- 88. He FJ, Brinsden HC, Macgregor GA. Salt reduction in the United Kingdom: A successful experiment in public health. J Hum Hypertens. 2014a;28(6): 345–52.
- 89. Mozaffarian D, Ashkan A, Benowitz NL, Bittner V, Daniels SR, Franch HA, et al. Population Approaches to Improve Diet, Physical Activity, and Smoking Habits. A Scientific Statement From the American Heart Association. Circulation. 2012; 126(12): 1514–1563 pmid:22907934
- 90. He FJ, MacGregor GA. A comprehensive review on salt and health and current experience of worldwide salt reduction programmes. J Hum Hypertens. 2009;23(6): 363–84. pmid:19110538
- 91. Pietinen P, Mannisto S, Valsta LM, Sarlio-Lähteenkorva S. Nutrition policy in Finland. Public Health Nutr. 2010;13(6A): 901–6. pmid:20513258
- 92. Wang G, Labarthe D. The cost-effectiveness of interventions designed to reduce sodium intake. J Hypertens. 2011;29(9): 1693–9. pmid:21785366
- 93. Webster JL, Dunford EK, Hawkes C, Neal BC. Salt reduction initiatives around the world. J Hypertens. 2011;29(6): 1043–50. pmid:21546876
- 94. Wang G, Bowman BA. Recent economic evaluations of interventions to prevent cardiovascular disease by reducing sodium intake. Curr Atheroscler Rep. 2013;15(9): 349. pmid:23881545
- 95. He FJ, Pombo-Rodrigues S, Macgregor GA. Salt reduction in England from 2003 to 2011: its relationship to blood pressure, stroke and ischaemic heart disease mortality. BMJ Open. 2014b;4(4): e004549.
- 96. Enkhtungalag B, Batjargal J, Chimedsuren O, Tsogzolmaa B, Anderson CS, Webster J. Developing a national salt reduction strategy for Mongolia. Cardiovasc Diagn Ther. 2015;5(3): 229–37. pmid:26090334
- 97. Luft FC, Morris CD, Weinberger MH. Compliance to a low-salt diet. Am J Clin Nutr. 1997;65(2): 698S–703S.
- 98. Mohan S, Campbell NRC, Willis K. Effective population-wide public health interventions to promote sodium reduction. CMAJ. 2009;181(9): 605–9. pmid:19752102
- 99. He FJ & MacGregor GA. Reducing population salt intake worldwide: from evidence to implementation. Prog Cardiovasc Dis. 2010;52(5): 363–82. pmid:20226955
- 100. Wyness LA, Butriss JL, Stanner SA. Reducing the population’s sodium intake: The UK Food Standards Agency’s salt reduction programme. Public Health Nutr. 2012;15(2): 254–61. pmid:21729460
- 101. Otsuka R, Kato Y, Imai T, Ando F, Shimokata H. Decreased salt intake in Japanese men aged 40 to 70 years and women aged 70 to 79 years: an 8-year longitudinal study. J Am Diet Assoc. 2011;111(6): 844–50. pmid:21616196
- 102. Du S, Batis C, Wang H, Zhang B, Zhang J, Popkin BM. Understanding the patterns and trends of sodium intake, potassium intake, and sodium to potassium ratio and their effect on hypertension in China. Am J Clin Nutr. 2014;99(2): 334–43. pmid:24257724
- 103. Miura K, Ando K, Tsuchihashi T, Yoshita K, Watanabe Y, Kawarazaki H, et al. [Scientific Statement] Report of the Salt Reduction Committee of the Japanese Society of Hypertension(2) Goal and strategies of dietary salt reduction in the management of hypertension. Hypertens Res. 2013;36(12): 1020–5. pmid:24152612
- 104. Asaria P, Chisholm D, Mathers C, Ezzati M, Beaglehole R. Chronic disease prevention: health effects and financial costs of strategies to reduce salt intake and control tobacco use. Lancet. 2007;370(9604): 2044–53. pmid:18063027
- 105. Dodhia H, Phillips K, Zannou M- I, Airoldi M, Bevan G. Modelling the impact on avoidable cardiovascular disease burden and costs of interventions to lower SBP in the England population. J Hypertens. 2012;30(1): 217–26. pmid:22080224
- 106. Gase LN, Kuo T, Dunet D, Schmidt SM, Simon PA, Fielding JE. Estimating the potential health impact and costs of implementing a local policy for food procurement to reduce the consumption of sodium in the county of Los Angeles. Am J Public Health. 2011;101(8): 1501–7. pmid:21680933
- 107. Ha DA, Chisholm D. Cost-effectiveness analysis of interventions to prevent cardiovascular disease in Vietnam. Health Policy Plan. 2011;26(3): 210–22. pmid:20843878
- 108. Laatikainen T, Critchley J, Vartiainen E, Salomaa V, Ketonen M, Capewell S. Explaining the Decline in Coronary Heart Disease Mortality in Finland between 1982 and 1997. Am. J. Epidemiol., 2005; 162: 764–773 pmid:16150890
- 109. Van Vliet BN, Campbell NRC, Canadian Hypertension Education Program. Efforts to reduce sodium intake in Canada: why, what, and when? Can J Cardiol. 2011;27(4): 437–45. pmid:21801976
- 110. Bech-Larsen T & Aschemann-Witzel J. A Macromarketing Perspective on Food Safety Regulation The Danish Journal of Macromarketing. 2012; 32(2) 208–219
- 111. Lloyd-Williams F, Bromley H, Orton L, Hawkes C, Taylor-Robinson D, O'Flaherty M, et al. Smorgasbord or symphony? Assessing public health nutrition policies across 30 European countries using a novel framework. BMC Public Health. 2014;14: 1195. pmid:25413832
- 112. MacGregor GA, He FJ, Pombo-Rodrigues S. Food and the responsibility deal: how the salt reduction strategy was derailed by Andrew Lansley and the coalition government. Br Med J. 2015;350: h1936.
- 113. Campos S, Doxey J, Hammond D. Nutrition labels on pre-packaged foods: a systematic review. Public Health Nutr. 2011;14(8): 1496–506. pmid:21241532
- 114. Cowburn G & Stockley L. Consumer understanding and use of nutrition labelling: a systematic review. Public Health Nutr. 2005;8(01): 21–8.
- 115. Wakefield MA, Loken B, Hornik RC. Use of mass media campaigns to change health behaviour. The Lancet. 2010; 376:1261–1271
- 116. Mols F, Haslam SA, Jetten J, Steffens NK. Why a Nudge is Not Enough: A Social Identity Critique of Governance by Stealth. Euro J Polit Res. 2014; 54(1): 87–98.
- 117. Fransen ML, Smit EG, Verlegh PWJ. Strategies and motives for resistance to persuasion: an integrative framework. Front Psychol. 2015;6: 1201. pmid:26322006
- 118. Forshee RA. Innovative regulatory approaches to reduce sodium consumption: could a cap-and-trade system work? Nutr Rev. 2008;66(5): 280–5. pmid:18454814
- 119. Bibbins-Domingo K, Chertow GM, Coxson PG, Moran A, Lightwood JM, Pletcher MJ, et al. Projected effect of dietary salt reductions on future cardiovascular disease. N Eng J Med. 2010;362(7): 590–9.
- 120. Barton P, Andronis L, Briggs A, McPherson K, Capewell S. Effectiveness and cost effectiveness of cardiovascular disease prevention in whole populations: Modelling study. BMJ. 2011;343: d4044. pmid:21798967
- 121. Cobiac LJ, Veerman L, Vos T. The role of cost-effectiveness analysis in developing nutrition policy. Annu Rev Nutr. 2013;33: 373–93. pmid:23642205
- 122. Owen L, Morgan A, Fischer A, Ellis S, Hoy A, Kelly MP. The cost-effectiveness of public health interventions. J Public Health. 2011;34(1): 37–45.
- 123. Beckmann S, Os I, Kjeldsen S, Eide I, Westheim A, Hjermann I. Effect of dietary counselling on blood pressure and arterial plasma catecholamines in primary hypertension. Am J hypertens. 1995;8(7): 704–11. pmid:7546496
- 124. Tian HG, Guo ZY, Hu G, Yu SJ, Sun W, Pietinen P, et al. Changes in sodium intake and blood pressure in a community-based intervention project in China. J Hum Hypertens. 1995;9(12): 959–68. pmid:8746640
- 125. Cappuccio FP. Salt and cardiovascular disease. Br Med J. 2007;334: 859–60.
- 126. Rodriguez-Fernandez R, Siopa M, Simpson SJ, Amiya RM, Breda J, Cappuccio FP. Current salt reduction policies across gradients of inequality-adjusted human development in the WHO European region: minding the gaps. Public Health Nutr. 2014;17: 1894–904. pmid:23924617
Fair Society, Healthy Lives. The Marmot Review. Strategic Review of Health Inequalities in England post-2010. Published by The Marmot Review. 2010;1–238.
- 128. Cappuccio FP, Ji C, Donfrancesco C, Palmieri L, Ippolito R, Vanuzzo D et al. Geographic and socioeconomic variation of sodium and potassium intake in Italy: results from the MINISAL-GIRCSI programme. BMJ Open. 2015;5: e007467. pmid:26359282
- 129. McGill R, Anwar E, Orton L, Bromley H, Lloyd-Williams F, O'Flaherty M, et al. Are interventions to promote healthy eating equally effective for all? Systematic review of socioeconomic inequalities in impact. BMC Public Health. 2015;15: 457. pmid:25934496
- 130. Lorenc T, Petticrew M, Welch V, Tugwell P. What types of interventions generate inequalities? Evidence from systematic reviews. J Epidemiol Community Health. 2012;67(2): 190–3. pmid:22875078
- 131. Orton L, Lloyd-Williams F, Taylor-Robinson D, O'Flaherty M, Capewell S. The Use of Research Evidence in Public Health Decision Making Processes: Systematic Review. PLoS ONE. 2011;6(7): e21704. pmid:21818262
- 132. Oliver K, Innvar S, Lorenc T, Woodman J, Thomas J. A systematic review of barriers to and facilitators of the use of evidence by Policymakers. BMC Health Services Research. 2014;14: 2. pmid:24383766
- 133. McKinlay JB & Marceau LD. Upstream healthy public policy: Lessons from the battle of tobacco. Int J Health Serv. 2000;30(1): 49–69. pmid:10707299
- 134. Krieger N. Proximal, Distal, and the Politics of Causation: What's Level Got to Do With It? Am J Public Health. 2008; 98: 221–230. pmid:18172144