Researchers from the University of Naples and the University of Warwick carried out the first study to link directly high salt intake with strokes and CVD events.
The research team analysed 13 studies involving 177,025 participants that had assessed habitual salt intake and rates of stroke and CVD events.
Until now, the benefits of reducing salt intake have been extrapolated from data on the effect of expected BP reductions on vascular outcomes, the researchers said.
Their study found that increasing salt intake by 5g a day raises the risk of stroke by 23 per cent and the risk of CVD by 17 per cent. The effect is dose-dependent and increased with the duration of exposure.
How much salt should we eat?
Lead researcher Professor Francesco Cappuccio, from the University of Warwick, said that the best recommendation on salt consumption would be 'the lower the better'.
'In the UK recommendations are to reduce it to 6g a day with the aim to further reduce it to 3g a day. The latter figure would be the ideal and feasible target,' he said.
GPs should advise patients to reduce salt intake as part of general lifestyle advice and should reinforce the message regularly, he added.
'Awareness of salt content of foodstuffs should be encouraged and monitoring of salt intake through 24-hour urine collections should be considered in the clinical setting. It is unfortunate that the NHS Health Checks have ignored this point,' Professor Cappuccio added.
What do other researchers say?
Victoria Taylor, senior heart health dietitian for the British Heart Foundation, said: 'This study reinforces the link between high intakes of salt and high BP, which is an important risk factor for heart disease and stroke.
'Our salt intake has started to improve with average consumption in the UK currently at 8.6g a day, having come down from 9.5g in 2000.
'This is promising but there is still a long way to go if we are to meet the recommended maximum of 6g a day or less, so we cannot be complacent.'
- A 5g rise in daily salt intake can increase stroke risk by 23 per cent.
- GPs should regularly advise patients to reduce salt intake as part of lifestyle guidance.
- Patients should look to reduce their daily salt intake to around 6g.