EARLY EVIDENCE FOR THE EFFECTIVENESS OF SOUTH AFRICA'S LEGISLATION ON SALT RESTRICTION IN FOODS: THE AFRICAN-PREDICT STUDY

Abstract

Objective: South Africa was one of the first countries to adopt mandatory regulation in 2016 to lower the salt content of a wide range of processed foods. To assess the effectiveness of this regulation, we determined the change in salt intake of young adults over a mean follow-up time of 4.56-years spanning the implementation of the regulation. Since young populations have a higher salt intake, salt reduction may have a greater long-term impact as a preventative strategy in this age group. Design and method: This study included baseline (N = 668; aged 24.9 ± 3 years; 47.8% black; 40.7% men) and follow-up data for the first 311 participants (aged 29.9 ± 3.09 years; 51.1% black; 43.4% men) tracked over time as part of the African-PREDICT study. Participants had baseline data before 30th June 2016, and follow-up from 2018 - 2020. Estimated salt intake at baseline and follow-up was calculated from 24-hour urinary sodium excretion. Results: The median salt intake of the population (N = 668) at baseline was 7.88 g/day (IQR: 5.67). In those followed (N = 311), salt intake reduced from baseline [median (IQR): 7.91 g/day (5.83)] to follow-up [median (IQR): 7.26 g/day (5.30)] in the total group [median difference (IQR): -0.82 g/day (7.02); p = 0.007], with a greater reduction observed in black adults [N = 159, median difference (IQR): -1.35 g/day (7.91); p = 0.003]. Reduced salt intake was more pronounced in black adults from a low (p = 0.007) and middle socio-economic status (p = 0.009), compared to a high socio-economic status (p = 0.27). Conclusions: Our preliminary findings suggest that South Africa's mandatory salt reduction regulation for processed foods has been effective in lowering salt intake in young adults by a magnitude of ∼0.82 g salt/day. Our study supports the effectiveness of “upstream” sodium reduction interventions at population level that may impact on the health and economic burden of countries.