title: Dietary sodium and iodine in remote Indigenous Australian communities: will salt-reduction strategies increase risk of iodine deficiency? A cross-sectional analysis and simulation study.
abstract: BACKGROUND
  Excess salt intake is a global issue. Effective salt-reduction strategies are needed, however, as salt is a vehicle for iodine fortification, these strategies may also reduce iodine intake. This study examines the case of the remote Indigenous Australian population; we employed an innovative, objective method to assess sodium and iodine intakes against requirements and modelled the potential effects of salt-reduction strategies on estimated sodium and iodine intakes.
  
  
  METHODS
  Store-sales data were collected from 20 remote Indigenous community stores in 2012-14 representing the main source of food for 2 years for ~8300 individuals. Estimated average sodium and iodine intakes were compared against recommendations (nutrient reference values weighted to age and gender distribution). Linear programming was employed to simulate potential effects of salt-reduction strategies on estimated sodium and iodine intakes.
  
  
  RESULTS
  Estimated average sodium intake was 2770 (range within communities 2410-3450) mg/day, far exceeding the population-weighted upper limit (2060 mg/day). Discretionary (added) salt, bread and processed meat were the biggest contributors providing 46% of all sodium. Estimated average iodine intake was within recommendations at 206 (186-246) μg/day. The following scenarios enabled modelling of estimated average salt intake to within recommendations: 1) 67% reduction in sodium content of bread and discretionary salt intake, 2) 38% reduction in sodium content of all processed foods, 3) 30% reduction in sodium content of all processed foods and discretionary salt intake. In all scenarios, simulated average iodine intakes remained within recommendations.
  
  
  CONCLUSIONS
  Salt intakes of the remote Indigenous Australian population are far above recommendations, likely contributing to the high prevalence of hypertension and cardiovascular mortality experienced by this population. Salt-reduction strategies could considerably reduce salt intake in this population without increasing risk of iodine deficiency at the population-level. These data add to the global evidence informing salt-reduction strategies and the evidence that these strategies can be synergistically implemented with iodine deficiency elimination programmes.
  
  
  BACKGROUND
  Australian New Zealand Clinical Trials Registry: ACTRN12613000694718.
authors.affiliation: Wellbeing and Preventable Disease Division, Menzies School of Health Research, PO Box 41096, Casuarina, NT, 0811, Australia. e.j.mcmahon@outlook.com.|Centre for Population Health Research, School of Health Sciences, University of South Australia, North Tce, Adelaide, SA, 5001, Australia. e.j.mcmahon@outlook.com.
authors.forename: Emma
authors.initials: E
authors.lastname: McMahon
authors.affiliation: Food Policy Division, The George Institute for Global Health, The University of Sydney, Missenden Rd, Sydney, NSW, 2050, Australia. jwebster@georgeinstitute.org.au.
authors.forename: Jacqui
authors.initials: J
authors.lastname: Webster
authors.affiliation: Centre for Population Health Research, School of Health Sciences, University of South Australia, North Tce, Adelaide, SA, 5001, Australia. Kerin.O'Dea@unisa.edu.au.
authors.forename: Kerin
authors.initials: K
authors.lastname: O'Dea
authors.affiliation: Wellbeing and Preventable Disease Division, Menzies School of Health Research, PO Box 41096, Casuarina, NT, 0811, Australia. Julie.Brimblecombe@menzies.edu.au.
authors.forename: Julie
authors.initials: J
authors.lastname: Brimblecombe
mesh_terms: D001315:Australia; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007455:Iodine / Q000172:deficiency*; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D012306:Risk; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage; D012982:Sodium, Dietary / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D017673:Sodium Chloride, Dietary; D012982:Sodium, Dietary; D007455:Iodine