Published: 11 February 2022
A new study published in The BMJ and carried out by researchers funded by the NIHR at Queen Mary University of London and The George Institute for Global Health at Peking University Health Science Centre, has shown that school children can help their families to successfully reduce salt intake via smartphone app-based learning.
The controlled trial, conducted in northern, central and southern China where salt intake is high amongst both children and adults, included 54 primary schools with over 590 children (aged 8-9 years) and over 1180 adult family members (including parents and grandparents with an average age of 46). During the study, children, parents and grandparents were taught about the dangers of eating too much salt and how to reduce it using a smartphone app, known as AppSalt. Salt reduction education, together with the routine health education curriculum, was integrated into the AppSalt system. Salt intake was measured at the beginning and 12 months into the app-based education, each involving two consecutive 24-hour urine collections. School teachers organised the evaluation and facilitated the salt reduction education by communicating with children and their families through virtual chats or in-personal meetings.
The average baseline salt intake (i.e. before the salt reduction education) was 5.5 g/d for 8-9 years-old children, and 10.0 g/d for adults which is double the World Health Organization (WHO) recommended level. After one year of education, salt intake fell by 8% (0.82 g/d, P<0.001) in adults which was accompanied by a fall of 1.6 mmHg (P<0.05) in systolic blood pressure. In children, there were small falls in salt intake and blood pressure, but they were not significant.
Salt reduction is one of the most cost-effective public health measures as it lowers blood pressure, the leading cause of cardiovascular disease (strokes, heart disease and heart failure). Approximately 80% deaths from cardiovascular disease occur in developing countries. Whilst China is the largest developing country in the world, there were ≈2.2 million stroke deaths and ≈1.9 million heart disease deaths in China during 2019. This continues to rise due to the rapid epidemiological and economic transitions.
Professor Feng He, Professor of Global Health Research at Queen Mary University of London and lead author said: “This study provides a novel and feasible approach to reducing salt intake in the population where most of the salt in the diet is added by the consumers. Nationwide implementation could support salt reduction efforts, leading to a reduction in salt intake in the Chinese population and therefore a reduction in strokes and heart disease.”
The study was funded by the NIHR Global Health Research Programme
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