Salt under the microscope
In 2016, the Swiss Federal Food Safety and Veterinary Office (FSVO) carried out a vast study of 25 different kinds of salt from around the world. Eva van Beek, a communications officer for the FSVO, explains “It was the first time we had scrutinised this type of foodstuff.” Such varieties of salt are now found in more and more shops and are often presented as being very natural and good for our health, when in fact we know very little about their chemical composition. The results published in May 2016 show that exotic varieties of salt are, on the whole, less ‘healthy’ than regular table salt, as they contain less iodine. Coloured salt only contains an average of 94% sodium chloride, compared to 99% for regular table salt, which means that it contains other elements. Aluminium, uranium and cadmium are among the contaminants found in coloured salt, although in quantities that are much too low to pose a health risk.1
Caroline Duparc, brand manager for Salines Suisses SA points out that, “As this study showed, Swiss table salt is particularly pure; our quality standards are very high.”
The supposed virtues of exoticism
If we take a closer look at the packaging of exotic salt, we can see that it frequently boasts its ‘purity’ (extracted in natural, inaccessible and pollution-free regions, as with Himalayan salt for example), as well as the high content of trace elements, since the salt is extracted directly from the rock. It often also highlights the absence of chemical or industrial treatments, or the fact that the salt was supposedly prepared by hand or in a small-scale enterprise. Not to mention the purifying, draining or stimulating properties of the minerals in such salt.
These supposed virtues come at a price. Certain types of salt can be up to 100 times more expensive than others.2 Caroline Duparc points out that, “There are as many varieties of salt as there are salt-producing regions. That is why these special kinds of salt are also part of our product range. However, we also like to ensure we offer a sufficient proportion of local condiments. Our traditional salt, for example, is an exceptionally pure handmade product from the Swiss Alps. A local alternative to fleur de sel.”
As previously mentioned, the FSVO study reveals that exotic salt is no better for our health than regular table salt. Persian blue salt, however, is an exception: It contains relatively high quantities of potassium, such that 5 g of this salt would cover one quarter of our daily requirements. On the other hand, Himalayan salt contains significant quantities of iron, which explains its pink hue. However, it is in the form of insoluble iron oxide, so it is difficult for the body to assimilate this mineral. Consequently, the FSVO maintains that Himalayan salt cannot be considered as a good nutritional source of iron.3
The Codex Alimentarius, a series of international standards issued by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO), includes the standards and references relating to the quality of food grade salt. Under ‘essential composition and quality factors’, the document stipulates that the sodium chloride content of food-grade salt “shall not be less than 97% on a dry matter basis, exclusive of additives.”4 The FSVO points out, however, that the sodium chloride content of some kinds of exotic salt is only 94%, or even as low as 88% in some cases.
Iodine, an essential mineral
The FSVO states that the special varieties of salt examined in its study are lacking in iodine. This trace element is important for the human body, as it is responsible for the formation of thyroid hormones.5 These hormones regulate most of our organs, including the central nervous system. Iodine deficiency can lead to excessive tiredness. In pregnant women, it can cause anomalies in the neurocognitive development of the foetus, or birth defects. However, as the symptoms are not very pronounced, many people are unaware that they lack sufficient iodine.
According to the Iodine Global Network, twenty countries are iodine deficient, compared to eleven that consume iron in excess.6 These figures show no apparent link between developed or developing countries. In Switzerland, 2% of men and 14% of women are iodine deficient.7 This difference is explained by the fact that women eat less and less salt. At the same time, cardiovascular diseases related to the excessive consumption of salt kill one million people in the world each year. A delicate balance has to be found.
The risks of a high-salt diet
Numerous studies have shown that most inhabitants of western countries consume between 7 g and 12 g of salt a day. In some countries, the consumption is even higher, as much as 22 g per person per day, as is the case in Korea.8
It is now widely accepted that excessive consumption of sodium is bad for our health. It can favour the development of high blood pressure as well as cardiovascular and kidney complications. As a consequence, the WHO, as well as public health authorities in many countries, and numerous medical companies, are focusing on action within communities to encourage a reduction in consumption of salt.9 The WHO recommends consuming a maximum of 5 g of salt a day, and its member states have decided to reduce the global intake of salt by 30% by 2025.10
According to specialists, it would be better to use table salt regularly and exotic salt only occasionally. Eva van Beek from the FSVO agrees. “Yes, the natural concentration of iodine is too low in special kinds of salt but, given the risk of cardiovascular diseases, it is advisable to limit our overall intake of salt, of any type.” The salt we ingest mainly comes from processed food, which we eat for its convenience. Taking the time (now and then) to cook our own meals from scratch using carefully selected products, and seasoning them very lightly with salt, could be a solution to this problem. Professor Andrew Mente recommends that, “A higher intake of potassium [rich] food like fruit and vegetables is also important, to help minimise the impact of sodium intake on blood pressure.”