Impact of Sodium Regulations on Consumption and Blood Pressure in Adults Aged 40 and Older

The present study was conducted to establish a link between regulations aimed at lowering sodium in processed foods, and the sodium intake and blood pressure of adults aged 40 and older. The country in 2013 implemented regulations that directed a 25% to 80% decrease in the maximum sodium levels allowed in 13 categories of processed foods by 2019.  

The HAALSI (Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa) study, which included adults aged 40 and older, analyzed data from three waves (2014/2015, 2018/2019, and 2021/2022) to observe changes in 24-hour urinary sodium excretion following the sodium regulations. Spot urine samples were collected, and data analysis occurred between 2023 and 2024. 24-hour urinary sodium excretion was estimated using the INTERSALT equation, and generalized estimating equations evaluated the changes in sodium excretion and blood pressure.

The results revealed the following findings:

• Among 5,059 participants (average age 62.43 years, 53.6% female), the baseline average 24-hour sodium excretion was 3.08 g. 
• There was an overall reduction of 0.22 g (95% CI, −0.27 to −0.17) in sodium excretion between the first two waves and a reduction of 0.23 g (95% CI, −0.28 to −0.18) between the first and third waves. 
• For participants with data from all three waves, the reductions were more pronounced (−0.26 g). 
• Each gram decrease in sodium excretion was associated with a reduction of 1.30 mm Hg (95% CI, 0.65-1.96) in systolic blood pressure, and the percentage of participants achieving ideal sodium intake (<2 g per day) rose from 7% to 17%.

The study concluded that the country’s regulations on sodium in processed foods led to a significant and sustained reduction in urinary sodium excretion and corresponding decreases in blood pressure within this rural population. These findings reinforce the potential health benefits of effective salt reformulation policies at the population level.

Source: Gaziano T, Kapaon D, du Toit JD, et al. Sodium Reduction Legislation and Urinary Sodium and Blood Pressure in South Africa. JAMA Cardiol. Published online February 05, 2025. doi:10.1001/jamacardio.2024.5410