State-level and community-level salt reduction initiatives: a systematic review of global programmes and their impact

Strengthening Knowledge to Practice on Effective Salt Reduction Interventions in Low- and Middle-Income Countries

PURPOSE OF REVIEW

The objective of this review was to consolidate available published information on the implementation and evaluation of salt reduction interventions in low- and middle-income countries (LMICs).

RECENT FINDINGS

The Science of Salt database (made up of studies identified in a weekly Medline search) was used to retrieve articles related to the implementation of salt reduction interventions from June 2013 to February 2020. Studies that measured the effects of the interventions in LMICs, based on four outcome measures-salt intake; sodium levels in foods; knowledge, attitudes, and behaviours (KABs) towards salt; and blood pressure-were included. Results were summarised overall and according to subgroups of intervention type, duration, sample size, country's income class, and regional classification. The review identified 32 studies, representing 13 upper middle-income and four lower middle-income countries. The main salt reduction interventions were education, food reformulation, and salt substitution; and many interventions were multi-faceted. More studies reported a positive effect of the interventions (decreased salt intake (12/17); lower sodium levels in foods or compliance with agreed targets (6/6); improved KAB (17/19); and decreased blood pressure (10/14)) than a null effect, and no study reported a negative effect of the intervention. However, many studies were of small scale and targeted specific groups, and none was from low-income countries. Consumer education, food reformulation, and salt substitution, either alone or in combination, were effective in their target populations. Supporting scale-up of salt reduction interventions in LMICs is essential to cover broader populations and to increase their public health impact.