According to a model calculation in the New England Journal of Medicine, each person doing without three grams of salt each day would translate in the USA alone into 44,000 – 92,000 fewer deaths per year. Kirsten Bibbins-Domingo and colleagues from the University of California in San Francisco expect 54,000-99,000 fewer heart attacks and 32,000-66,000 fewer strokes a year. The U.S. health care system would be saved annual costs of ten to 24 billion U.S. dollars.
But right now everything looks different: Physicians working under Jan Staessen at the University of Leuven observed almost 3,700 adults who had not suffered from heart disease and determined their salt intake indirectly via the sodium content of their urine. After seven years came the surprise: both the proportion of deaths and the number of non-fatal heart attacks and strokes was greatest in the group who consumed the least salt.
WHO: suppressing salt consumption with effect
But almost the moment that this study was published in the journal Jama, critics raised their hands. The study is said to have been poorly carried out. The collection of urine is problematic, since for instance it can not be ascertained that the participants really saved all the liquid. In addition, the volunteers at the beginning of the study were, with some of them being under 40 years of age, too young and so the number of health incidents such as strokes or heart attacks too minimal.
Graham MacGregor of the Queen Mary University additionally commented in Tagesspiegel: ”It has always has been shown: Anything that lowers blood pressure is useful against heart attack and stroke.” He says that the evidence of the beneficial effect gained via less salt in food is overwhelming. The reduction in salt consumption is, after the fight against tobacco, the next major assignment. A large meta-analysis from the past year supports this view. In a total of 13 trials with 177 025 participants and of study durations between 5 to 19 years, the rate of stroke increased by 23 percent and diseases of the cardiovascular system by 17 percent when the participants had a very salty eating pattern. And so the World Health Organization has taken up the cause to effectively bring down salt intake. It recommends a salt intake for adults per person per day of a maximum of five grams. Currently in Europe, however, it sits significantly higher, namely at eight to twelve grams.
Reactions to the big salt-flood
But not all researchers are in favour of our favorite condiment. It is true that hypertension is a widespread disease in Germany: Some 44 percent of women and 51 percent of men suffer from having too much pressure in their blood vessels. However, some scientists have doubted for some time that the amount of salt in food contributes to high blood pressure. Also the effect that comes from a low-salt diet in this respect is said to be extremely low. In fact, an analysis of the globally recognised Cochrane Institute showed that the average systolic blood pressure fell only about 1 mm Hg when the average daily salt intake was reduced. The diastolic values decreased even less. Only in people with high blood pressure was the effect more pronounced. The authors expect with these results, “no great health benefits.” Moreover, it is very difficult to keep a low-salt diet, as most of the salt that we take in does not come from the salt shaker, but rather is concealed in processed products such as dried soups, prepared sauces, frozen pizza, cheese or salami. Some countries already responded to this “industry-based salt-flood” several years ago. Finland for instance indicates the salt content of its foods.
On packs of cheese, bread or prepared meals there sits a little red heart for low salt and fat content. The Finnish word “voimakassuolainen”, on the other hand, warns the consumer about highly salted foods. Thus, the consumer in the supermarket can tell at a glance what ends up in front of them on the plate. Since these identification and awareness campaigns have taken place, the rate of heart attacks and strokes in Finland has declined significantly.
Safe or dangerous? So far it seems that in relation to salt nobody can answer that question conclusively. This may come down to the fact that, in order to resolve it, there would need to be more large studies, whereby the causality between salt consumption and increased mortality really can be demonstrated. Most of the studies now are, however, either methodologically weak, or are set-up over too short a period to assess whether fewer people really die if they eat less salt. In addition, it’s also vital to demonstrate physiologically exactly how salt harms the body.