By JR on Wednesday, July 06, 2011
Cutting back on salt 'does not make you healthier' (despite nanny state warnings)
Cochrane reviews are reviews of the best available evidence on the subject so attempts to discredit this study are unconvincing. That the review looked at "only" seven studies would indicate that other available studies were not of review quality
Eating less salt will not prevent heart attacks, strokes or early death, according to a major study. Its findings contradict all recommendations by the Government and medical profession urging the public to reduce the amount of salt they consume.
Research involving nearly 6,500 people concluded that there was ‘no strong evidence’ that lowering levels in the diet reduced the risk of heart disease or premature death. In fact it found that cutting back on salt actually raises the likelihood of death in some patients with heart problems.
The researchers from Exeter University say that the benefits of cutting back on salt may have been ‘overestimated’. They also point out that there are other important lifestyle factors such as eating fruit, taking exercise, following a low-fat diet and not smoking which will also affect the health of an individual.
The findings have been criticised by campaigners and other scientists, who say there is strong evidence that reducing levels of salt will protect the heart.
They say the reason the study did not show that cutting back on salt prevented heart attacks may be because the people involved reduced their intake only for short periods of time.
Large amounts of salt in the diet increase the risk of high blood pressure, which can lead to heart attacks and strokes. Currently adults are advised to eat no more than 6g of salt a day – or one teaspoon – but it is estimated they average 9g a day.
The Government has begun working with manufacturers, fast food firms and restaurants to try to get them to reduce the amount of salt in their products. And in recent years there have been campaigns urging the public to try to cut down on foods high in it, such as ready meals, takeaways and cereals.
But research published today in the Cochrane Review journal concludes there is limited evidence that cutting down on salt reduces the risk of illness or early death.
The authors from Exeter University looked at seven published studies involving 6,489 people. Some had high blood pressure, others had normal blood pressure and they had all been put on salt-reduction diets.
But the authors found that there was no evidence that cutting down reduced deaths or heart disease in either group. And they found that patients with heart failure who cut back on salt were actually at higher risk of death – possibly because the change in diet is such a shock to the body.
But the researchers insist that their study does not mean government salt reduction campaigns have been a waste of time. Lead researcher Rod Taylor, from the University of Exeter, said: ‘Perhaps surprisingly we didn’t find any statistically significant reduction in death or cardiovascular events such as heart attacks and strokes.’
He pointed out that most of the previous research showing that diets low in salt prevent heart disease do not account for the fact people who eat less salt are healthy in general – they take exercise, eat plenty of fruit and tend not to smoke.
He suggested the public would need to cut back on salt for long periods to benefit. The only way this could be done would be to get restaurants, fast food chains and office canteens to reduce the content in their meals.
Katharine Jenner, of Consensus Action on Salt and Health, said: ‘It is very disappointing that the message from this small review indicates that salt reduction may not be beneficial. ‘This is a completely inappropriate conclusion, given the strong evidence and the overwhelming public health consensus that salt raises blood pressure which leads to cardiovascular disease.
‘This review is based on just seven studies that were not designed to test the effects of sodium reduction interventions on cardiovascular events and mortality.’
Simon Capewell, professor of clinical epidemiology at the University of Liverpool, said the study was disappointing and inconclusive.