Sodium Reduction Legislation and Urinary Sodium and Blood Pressure in South Africa
Authors' conclusion
In this cohort study, following South African regulations limiting sodium in 13 categories of processed foods, there was a significant reduction in 24HrNa excretion among this rural South African population, which was sustained with reductions in blood pressure consistent with levels of sodium excreted.
Study context
- Population
- Adults aged ≥40 years, rural Mpumalanga Province, South Africa (HAALSI cohort), after 2013 regulations limiting sodium in 13 processed food categories
- Participants
- 5,059 adults
- Exposure
- Sodium excretion and BP before vs after mandatory sodium regulations
- Outcome
- Change in estimated 24-hour urine sodium excretion (INTERSALT equation) and BP
Methodological detailspopulation-based, 3 waves (2014/2015, 2018/2019, 2021/2022)
- Population-based
- 3 waves (2014/2015, 2018/2019, 2021/2022)
Main finding
As reported in the abstract
Estimated 24HrNa excretion
Baseline
3.08
mean · SD 0.78 · g
- First 2 waves · between the first 2 waves
- mean reduction 0.22 g (95% CI −0.27 to −0.17); P < 0.001
- First and third waves · between the first and third waves
- mean reduction 0.23 g (95% CI −0.28 to −0.18); P < 0.001
Observational data: associations, not effects.
Further findings
24-hour urine sodium, participants with samples in all 3 waves
- Reduction for both waves 2 and 3 vs wave 1
- −0.26 g
SBP per gram of sodium reduction
- SBP reduction per gram sodium reduction
- −1.30 mm Hg (95% CI, 0.65-1.96; P = .00)
Ideal sodium consumption (<2 g per day)
- Proportion achieving ideal sodium consumption increased
- from 7% to 17%
Original publication
Sodium Reduction Legislation and Urinary Sodium and Blood Pressure in South Africa. JAMA Cardiol. Published 1 April 2025. doi:10.
Summarised from the published abstract; every number is checked against it