Writing in the American Journal of Clinical Nutrition, scientists from the Dutch National Institute for Public Health and the Environment found that the average salt intake in Dutch adults is about 8.4 grams per day, significantly higher than the World Health Organisation (WHO) recommendation of a maximum daily salt intake of 5 g – equivalent to about 2,000 mg of sodium.
Additional calculations by the researchers found that, if everyone met the Dutch recommendations (maximum of 6g/d of salt), the number of heart attacks may be reduced by almost 5%, the number of congestive heart failure cases reduced by almost 2%, and stroke by almost 6%.
“It has been suggested that there is no compelling evidence from randomized controlled trials that salt restriction will result in lower [cardiovascular disease] events, but reanalysis of these data showed a significant risk reduction,” wrote the researchers, led by Marieke Hendriksen.
“An adverse effect of current salt intake contents on CVD through blood pressure was recently confirmed by the US Institute of Medicine after combining all available evidence from clinical outcome studies.”
Salt is, of course, vital and is necessary for the body to function, but campaigners for salt reduction, like the Consensus Action on Salt and Health (CASH) consider the average daily salt consumption in the western world, between 10 and 12g, far too high.
Numerous scientists are convinced that high salt intake is responsible for increasing blood pressure (hypertension), a major risk factor for cardiovascular disease (CVD) - a condition that causes almost 50% of deaths in Europe.
In countries like the USA, the UK, and Ireland, and other industrialized countries, over 75% of salt intake comes from processed foods
For the new study, the Dutch scientists evaluated the potential health benefits of two salt-reduction strategies (substitution of high-salt foods with low-salt foods or reduction of the sodium content of processed foods) to meet the recommended maximum salt intake (6 g/d).
Mathematical models showed that meeting the recommended levels of salt intake then there could be a 4.8% reduction in acute myocardial infarctions (heart attacks), a 1.7% reduction in coronary heart failure, and a 5.8% reduction in stroke.
The gains were greater by substituting high-salt foods with low-salt alternatives, they said, but their estimates for sodium reduction in processed foods would be slightly lower.
“Salt reduction to the recommended maximum intake of 6 g/d is challenging,” wrote Hendriksen and her co-workers. “This study modeled 2 maximal potential scenarios related to reduce salt intake through either behavioral change (substitution processed foods scenario) or food reformulation (salt reduced processed foods scenario). Both approaches yielded roughly similar estimates and are close to the recommended maximum intake. It should be stressed that both scenarios may overestimate the actual salt intake reduction.
“Presumably not every individual can be persuaded to choose a diet with low-salt alternatives. Likewise, it would require major efforts by food industry to reduce the sodium content in processed foods by 50%. In certain foods sodium can easily be reduced, whereas in other foods sodium reduction will be more challenging. Thus, the health benefits of more realistic versions of our strategies will probably be lower than the projected effects in our study.”
Source: American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.3945/ajcn.113.062018
“Potential effect of salt reduction in processed foods on health”
Authors: M.A.H. Hendriksen, R.T. Hoogenveen, J. Hoekstra, J.M. Geleijnse, H.C. Boshuizen, J.M.A. van Raaij