Emphasized warning reduces salt intake: a randomized controlled trial

A new study by researchers in Croatia and Bosnia found that applying warning stickers on all household salt containers, similar to warning signs found on cigarette packets, significantly reduced salt intake and blood pressure (BP) in adults treated for hypertension. The randomised controlled trial split 150 participants into 2 groups: the control group (n=74) who received a leaflet about the harmful effects of salt and the intervention group (n=76) who in addition, received warning stickers. 

Salt intake was measured by 24-hr urinary sodium excretion (Na24) at the start of the trial and  after 1 and 2 months. The average starting Na24 was 207 ± 71 mmol in the control group and 211 ±  85 mmol in the intervention group (P = .745). One month and 2 months later, a significant decrease was observed in the intervention group (to 183 ±  63 mmol and 176 ±  55 mmol; P < .0001), as opposed to the control group (203 ±  60 mmol and 200 ± 58 mmol; P = .1466).

As the majority of salt in less developed countries is added during cooking or at the table, an important strategy to reduce population salt intake would be to encourage the general public to reduce the amount of salt used at home. This study has demonstrated that applying health warning stickers could be part of such a strategy

The authors (Markota NP et al) concluded that “A short-term intervention cannot completely correct dietary habits, but in the long run, combined with other measures, it may significantly contribute to a reduction in salt intake and BP lowering, particularly in countries where industrial, processed food is not the main source of sodium.”

Steph Tucker, Assistant Nutritionist at CASH says “We can replicate this ourselves at home to remind us of the negative effects of eating too much salt and to make us think twice before automatically reaching for the salt shaker. As 10-15% of salt intake in the UK is from salt added during cooking or at the table, it is beneficial for us all to reduce the amount we’re adding. With a larger of proportion of salt already added to our food, the food industry have an important role in reducing the salt content of the food we eat.”

Click here for the paper.