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

Background High-salt diets are linked to elevated blood pressure, a major risk factor for cardiovascular diseases, particularly stroke. State and community salt reduction strategies may complement nationally led initiatives and contribute to achieving global salt reduction targets. We aim to systematically review such interventions and document reported impact where programmes have been evaluated. Methods Electronic databases were searched up to June 2015 using terms ‘salt’ or ‘sodium’ and ‘state’ and ‘community’ in combination with ‘campaign’, ‘initiative’, ‘project’, ‘strategy’, ‘intervention’ or ‘programme’. Data from evaluated and unevaluated interventions were included. Studies were analysed in relation to intervention components and outcome measures and appraised for quality using a Cochrane Risk-of-Bias Tool. Results 39 state and community programmes were identified. Settings varied from whole communities (n=23), state-owned buildings (n=5), schools (n=7), workplaces (n=3) and correctional facilities (n=1). Strategies included nutrition education programmes, public education campaigns, changes to the food environment, other ‘novel’ approaches and multifaceted approaches. Of the 28 studies that evaluated intervention effectiveness, significant reductions were observed in terms of salt intake from dietary assessment (n=7), urinary sodium excretion (n=8), blood pressure (n=11) and sodium in foods (n=9). Six studies reported positive changes in consumer knowledge, attitudes and behaviours. All but two studies had some methodological limitations. Conclusions State and community salt reduction programmes may be effective in a range of settings but more robust evaluation methods are needed. Scaling up these efforts in coordination with national initiatives could provide the most effective and sustainable approach to reducing population salt intake.