How will South Africa's mandatory salt reduction policy affect its salt iodisation programme? A cross-sectional analysis from the WHO-SAGE Wave 2 Salt and Tobacco study

BMJ Open

Volumn 8, Issue 3, 2018, Pages

  Charlton, Karen ^a,b   Ware, Lisa Jayne ^c,d   Baumgartner, Jeannine ^c   Cockeran, Marike ^c   Schutte, Aletta E ^c   Naidoo, Nirmala ^e   Kowal, Paul ^e,f  

^a UNIVERSITY OF WOLLONGONG   (Australia)

^b ILLAWARRA HEALTH AND MEDICAL RESEARCH INSTITUTE   (Australia)

^c NORTH WEST UNIVERSITY   (South Africa)

^d UNIVERSITY OF THE WITWATERSRAND MEDICAL SCHOOL   (South Africa)

^e WORLD HEALTH ORGANIZATION   (Switzerland)

^f UNIVERSITY OF NEWCASTLE   (Australia)

Author keywords

dietary; food; iodine; legislation; nutritional requirements; policy; sodium

Indexed keywords

IODINE; SODIUM CHLORIDE; IODIZED SALT;

ADULT; ARTICLE; COHORT ANALYSIS; CROSS-SECTIONAL STUDY; HEALTH PROGRAM; HUMAN; IODINATION; IODINE DEFICIENCY; MAJOR CLINICAL STUDY; OBSERVATIONAL STUDY; POLICY; SALT INTAKE; SALT IODIZATION PROGRAM; SALT REDUCTION POLICY; SAMPLE; SODIUM EXCRETION; SODIUM URINE LEVEL; SOUTH AFRICA; URINALYSIS; URINE SAMPLING; AGED; DEFICIENCY; FEMALE; FORTIFIED FOOD; LONGITUDINAL STUDY; MIDDLE AGED; NUTRITION POLICY; NUTRITIONAL STATUS; PREGNANCY;

ADULT; AGED; CROSS-SECTIONAL STUDIES; FEMALE; FOOD, FORTIFIED; HUMANS; IODINE; LONGITUDINAL STUDIES; MIDDLE AGED; NUTRITION POLICY; NUTRITIONAL STATUS; PREGNANCY; SODIUM CHLORIDE, DIETARY; SOUTH AFRICA;

EID: 85053032779     PISSN: None     EISSN: 20446055     Source Type: Journal    
DOI: 10.1136/bmjopen-2017-020404     Document Type: Article

References (44)

1. Andersson M, de Benoist B, Delange F, et al. Prevention and control of iodine deficiency in pregnant and lactating women and in children less than 2-years-old: Conclusions and recommendations of the Technical Consultation. Public Health Nutr 2007:10:1606-11.
2. World Health Organization. United Nations Children's Fund; International Council for the Control of Iodine Deficiency Disorders. Assessment of iodine deficiency disorders and monitoring their elimination: A guide for programme managers. 3rd ed. Geneva: World Health Organization, 2007.
3. WHO Guideline on Fortification of food-grade salt. WHO: Geneva, 2014. http://www. who. int/nutrition/publications/guidelines/fortification-foodgrade-saltwithiodine/en/.
4. United Nations System. Standing Committee on Nutrition (SCN) News. Universal Salt Iodisation. 35, 2007. ISSN 1564-3743. (accessed 17 Jul 2017).
5. United Nations Children's Fund (UNICEF). The State of the World's Children. New York: UNICEF, 2016. https://www. unicef. org/sowc2016/. (cited 12 Jan 2018).
6. The Iodine Global Network. Global Iodine Nutrition Scorecard. Zurich, 2016. http://www. ign. org/cmdata/Scorecard-2016-SAC-PW. pdf. (accessed 12 Jan 2018).
7. Gizak M, Gorstein J, Andersson M. Epidemiology of Iodine Deficiency. Pearce E, ed. Iodine Deficiency Disorders and Their Elimination. Ebook. 35: Springer, 2017. https://link. springer. com/book/10.1007/978-3-319-49505-7.
8. Andersson M, Karumbunathan V, Zimmermann MB. Global iodine status in 2011 and trends over the past decade. J Nutr 2012;142:744-50.
9. The Iodine Global Network. Global iodine nutrition scorecard 2015. Zurich: The Iodine Global Network, 2015. http://www. ign. org/cmdata/Scorecard-2015-August-26-new. pdf. (cited 1 Jan 2018).
10. Zimmermann MB, Jooste PL, Pandav CS, et al. Iodine-deficiency disorders. The Lancet 2008;372:1251-62.
11. Effects of mandatory iodization on the iodine content of retailers and household salt in South Africa. 8th World Salt Symposium, 2000.
12. Joint FAO/WHO Expert Committee on Food Additives. WHO Technical Report Series, No. 806, Annex 5. Geneva: World Health Organization, 1991.
13. Jooste P, Zimmermann M. Progress towards eliminating iodine deficiency in South Africa. South African Journal of Clinical Nutrition 2008;21:8-14.
14. Jooste PL, Labadarios D, Nel H, et al. Iodine content of household salt, drinking water and iodine status of women and children. National Food Consumption Survey-Fortification baseline (NFCS-FB): South Africa 2005. Stellenbosch, South Africa, 2007:387-407.
15. Labadarios D, Swart R, Maunder E, et al. The National Food Consumption Survey-Fortification Baseline (NFCS-FB): South Africa, 2005. Pretoria: Directorate: Nutrition, Department of Health, 2007.
16. Jooste PL, Weight MJ, Lombard CJ. Iodine concentration in household salt in South Africa. Bull World Health Organ 2001;79:534-40.
17. Webster JL, Dunford EK, Hawkes C, et al. Salt reduction initiatives around the world. J Hypertens 2011;29:1043-50.
18. Trieu K, Neal B, Hawkes C, et al. Salt Reduction Initiatives around the World-A Systematic Review of Progress towards the Global Target. PLoS One 2015;10:e0130247.
19. Charlton K, Webster J, Kowal P. To legislate or not to legislate? A comparison of the UK and South African approaches to the development and implementation of salt reduction programs. Nutrients 2014;6:3672-95.
20. Charlton KE, Steyn K, Levitt NS, et al. Ethnic differences in intake and excretion of sodium, potassium, calcium and magnesium in South Africans. Eur J Cardiovasc Prev Rehabil 2005;12:355-62.
21. Charlton KE, Steyn K, Levitt NS, et al. A food-based dietary strategy lowers blood pressure in a low socio-economic setting: A randomised study in South Africa. Public Health Nutr 2008;11:1397-406.
22. Charlton KE, Steyn K, Levitt NS, et al. Diet and blood pressure in South Africa: Intake of foods containing sodium, potassium, calcium, and magnesium in three ethnic groups. Nutrition 2005;21:39-50.
23. Report number R214: Foodstuffs, cosmetics and disinfectants Act, 1972 (Act 54 of 1972). Regulations relating to the reduction of sodium in certain foodstuffs and related matters: South African Department of Health, 2013.
24. Bertram MY, Steyn K, Wentzel-Viljoen E, et al. Reducing the sodium content of high-salt foods: Effect on cardiovascular disease in South Africa. S Afr Med J 2012;102:743-5.
25. Watkins DA, Olson ZD, Verguet S, et al. Cardiovascular disease and impoverishment averted due to a salt reduction policy in South Africa: An extended cost-effectiveness analysis. Health Policy Plan 2016;31:75-82.
26. Verkaik-Kloosterman J, van 't Veer P, Ocke MC. Reduction of salt: Will iodine intake remain adequate in The Netherlands? Br J Nutr 2010;104:1712-8.
27. Charlton KE, Jooste PL, Steyn K, et al. A lowered salt intake does not compromise iodine status in Cape Town, South Africa, where salt iodization is mandatory. Nutrition 2013;29:630-4.
28. Kowal P, Chatterji S, Naidoo N, et al. Data resource profile: The World Health Organization Study on global AGEing and adult health (SAGE). Int J Epidemiol 2012;41:1639-49.
29. Charlton K, Ware LJ, Menyanu E, et al. Leveraging ongoing research to evaluate the health impacts of South Africa's salt reduction strategy: A prospective nested cohort within the WHO-SAGE multicountry, longitudinal study. BMJ Open 2016;6:e013316.
30. World Medical Association. Declaration of Helsinki-Ethical principles for medical research involving human subjects (as amended by the 64th WMA General Assembly, Fortaleza, Brazil, October 2013, 2013. https://www. wma. net/policies-post/wmadeclaration-of-helsinki-ethical-principles-for-medical-researchinvolving-human-subjects/).
31. WHO/PAHO Regional Expert Group for Cardiovascular Disease Prevention through Population-wide Dietary Salt Reduction. Protocol for population level sodium determination in 24-hour urine samples. Geneva: World Health Organization, 2010.
32. Nicar MJ, Hsu MC, Johnson T, et al. The preservation of urine samples for determination of renal stone risk factors. Lab Med 1987;18:382-4.
33. Stolarz-Skrzypek K, Kuznetsova T, Thijs L, et al. Fatal and nonfatal outcomes, incidence of hypertension, and blood pressure changes in relation to urinary sodium excretion. JAMA 2011;305:1777-85.
34. Ohashi T, Yamaki M, Pandav CS, et al. Simple microplate method for determination of urinary iodine. Clin Chem 2000;46:529-36.
35. Caldwell KL, Makhmudov A, Jones RL, et al. EQUIP: A worldwide program to ensure the quality of urinary iodine procedures. Accreditation and Quality Assurance 2005;10:356-61.
36. Delange F, de Benoist B, Burgi H. ICCIDD Working Group. International Council for Control of Iodine Deficiency Disorders. Determining median urinary iodine concentration that indicates adequate iodine intake at population level. Bull World Health Organ 2002;80:633-6.
37. Karmisholt J, Laurberg P, Andersen S. Recommended number of participants in iodine nutrition studies is similar before and after an iodine fortification programme. Eur J Nutr 2014;53:487-92.
38. Ware LJ, Charlton K, Schutte AE, et al. Associations between dietary salt, potassium and blood pressure in South African adults: WHO SAGE Wave 2 Salt & Tobacco. Nutr Metab Cardiovasc Dis 2017;27:784-91.
39. Institute of Medicine Academy of Sciences, USA. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese,Molybdenum, Nickel, Silicon, Vanadium and Zinc. Washington, DC: The National Academies Press, 2001. https://www. ncbi. nlm. nih. gov/pubmed/25057538.
40. Harris MJ, Jooste PL, Charlton KE. The use of iodised salt in the manufacturing of processed foods in South Africa: Bread and bread premixes, margarine, and flavourants of salty snacks. Int J Food Sci Nutr 2003;54:13-19.
41. Wentzel-Viljoen E, Steyn K, Lombard C, et al. Evaluation of a Mass-Media Campaign to Increase the Awareness of the Need to Reduce Discretionary Salt Use in the South African Population. Nutrients 2017;9:1238.
42. Webster J, Crickmore C, Charlton K, et al. South Africa's salt reduction strategy: Are we on track., what lies ahead? SAMJ: South African Medical Journal 2017;107:20-1.
43. Bourdoux P. Evaluation of the iodine intake: Problems of the iodine/creatinine ratio-comparison with iodine excretion and daily fluctuations of iodine concentration. Exp Clin Endocrinol Diabetes 1998;106:S17-S20.
44. Ronquest-Ross L-C, Vink N, Sigge G. Department of Food Science, Stellenbosch University, Stellenbosch, South Africa. Food consumption changes in South Africa since 1994. S Afr J Sci 2015;111:1-12.