1 August 2011
The public has been seriously misled about salt and risk of heart attack and stroke due to a flawed Cochrane review, UK preventive medicine experts say.
The Cochrane review - which analysed 7 trials of reducing salt intake - concluded that cutting down on salt has "no clear benefit" in terms of saving lives or reducing heart attacks and strokes (Cochrane Database of Systematic Reviews 2011; 7: CD009217).
The anti-salt campaigners dispute the inclusion of a trial in which the effect of reducing salt was tested in patients with salt and water loss caused by diuretic medicines. This skewed the conclusions leading to headlines such as 'Now salt is safe to eat – health fascists proved wrong', they wrote in a commentary in the journal The Lancet (2011; 378: 380-82).
They said re-analysis of the remaining 6 trials showed a significant 20 per cent reduction in cardiovascular events (heart attack and stroke) and a non-significant reduction in deaths with just a small reduction in salt intake of 2-2.3 grams per day.
The Cochrane review and accompanying press release, headlined 'Cutting down on salt does not reduce your chance of dying', were incorrect and "reflect poorly on the reputation of the Cochrane Library [the international collaboration that aims to help people make well-informed health decisions] and the authors", they said, adding the public was "seriously misled".
Meanwhile, for the first time in an Australian community, researchers have shown sodium (salt) intake is associated with increasing systolic blood pressure (BP). The study analysed urine samples from 600 people for sodium and potassium levels, which indicate daily salt intake. The association between urine sodium and BP was not altered after taking into account body mass index (BMI) or use of blood pressure medicines (Medical Journal of Australia 2011; 195: 128-32).
In an editorial, Professor Bruce Neal, Australian chair of World Action on Salt and Health, said the findings suggested that daily intake of salt 6 grams above the amount required by the body could lead to systolic BP being pushed up 25 mmHg over 50 years (Med J Aust 2011; 195: 111-2).
Last Reviewed: 01 August 2011