Health and Economic Impacts of Eight Different Dietary Salt Reduction Interventions

Abstract

BackgroundGiven the high importance of dietary sodium (salt) as a global disease risk factor, our objective was to compare the impact of eight sodium reduction interventions, including feasible and more theoretical ones, to assist prioritisation.MethodsEpidemiological modelling and cost-utility analysis were performed using a Markov macro-simulation model. The setting was New Zealand (NZ) (2.3 million citizens, aged 35+ years) which has detailed individual-level administrative cost data.ResultsOf the most feasible interventions, the largest health gains were from (in descending order): (i) mandatory 25% reduction in sodium levels in all processed foods; (ii) the package of interventions performed in the United Kingdom (UK); (iii) mandatory 25% reduction in sodium levels in bread, processed meats and sauces; (iv) media campaign (as per a previous UK one); (v) voluntary food labelling as currently used in NZ; (vi) dietary counselling as currently used in NZ. Even larger health gains came from the more theoretical options of a “sinking lid” on the amount of food salt released to the national market to achieve an average adult intake of 2300 mg sodium/day (211,000 QALYs gained, 95% uncertainty interval: 170,000 – 255,000), and from a salt tax. All the interventions produced net cost savings (except counselling – albeit still cost-effective). Cost savings were especially large with the sinking lid (NZ$ 1.1 billion, US$ 0.7 billion). Also the salt tax would raise revenue (up to NZ$ 452 million/year). Health gain per person was greater for Māori (indigenous population) men and women compared to non-Māori.ConclusionsThis study substantially expands on the range of previously modelled salt reduction interventions and suggests that some of these might achieve major health gains and major cost savings (particularly the regulatory interventions). They could also reduce ethnic inequalities in health.

Cost-effectiveness of salt reduction to prevent hypertension and CVD: a systematic review

“…A total of 1351 articles were identified. After screening and applying the eligibility criteria, fourteen full economic analyses (32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45) describing cost-effectiveness of salt reduction in Australia, Europe, New Zealand and the USA were included. Figure 1 shows the study selection process.…”

The impact of food reformulation on nutrient intakes and health, a systematic review of modelling studies

“…Overall, studies were heterogeneous in the way interventions and outcomes were modelled and reported, limiting between-study comparisons. As regards the type of nutrient reformulated, 20 studies focused exclusively on sodium reduction (60.6%) [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41], followed by 5 studies considering at least 2 different nutrients (15.1%) [8,[42][43][44][45], 5 studies addressing sugar (15.1%) [46][47][48][49][50] and 3 study addressing fat (9%) [11,51,52].…”

“…This limited between-study comparisons, since results were sensitive to the time horizon of the analysis, the size of the modelled population, and baseline risk factors, which varied across studies. In the studies for which it was possible to calculate gains per 100,000 population, reductions in the sodium content of foods resulted in an increase between 265 QALYs and 12,783 QALYs [28][29][30], or in a reduction between 6.35 and 1452 DALYs [23,24,36]. Although based on less studies, results seem to be consistent across models, showing a positive association between sodium reductions and QALYs (DALYs) gained (lost).…”

“…Target foods in the included studies were all processed foods (n = 9) [27,31,33,37,38,41,45,51,52], selected groups of nutrient-dense foods (n = 8) [11, 26, 34-36, 43, 44, 50], or single food products (n = 8) [23,24,42,[46][47][48][49]. Four studies provided estimates for more than one item [8,[28][29][30], whereas in 4 studies target foods were not specified since reformulation was modelled directly through its assumed effect on intake [22,25,32,39]. Ten studies simply estimated changes in intake following reformulation (30.3%) [8,11,26,33,42,43,45,49,50,53], whereas other studies estimated effects on health outcomes (n = 12, 36.4%) [25, 31, 35, 37, 39-41, 44, 46-48, 51] or health related quality of life measures (n = 11, 33.3%) [22-24, 28-30, 32, 34, 36, 38, 52].…”

Designing low-cost “heart healthy bread”: optimization using linear programing and 15-country comparison

“…For example, a number of European governments aim to reduce sodium intakes by regulating the maximal level of sodium in bread [7,8]. This action is supported by various modeling studies that suggest both health and economic advantages of reducing sodium in bread (e.g., for Argentina [9][10][11], Australia [12,13], New Zealand [14] and South Africa [15]). Furthermore, there have been successful studies and interventions to replace sodium chloride in bread with potassium salts [16][17][18].…”