Hold the Sea salt

Confused about salt? You’re not the only one. Let me take you through the various ways in which salt is produced and some key distinctions between them.

The term “salt” actually just describes a compound comprised of a positively charged ion and a negatively charged ion. For example, potassium iodide (KI) and magnesium chloride (MgCl2) are both salts, comprised of K+/I- and Mg2+/(2)Cl-, respectively. The “salt” we sprinkle on food refers to the specific compound sodium chloride, NaCl. When we talk about the health effects of this compound, however, we have historically concerned ourselves mainly with the sodium content. Most people are familiar with the idea that a diet high in sodium can cause elevated blood pressure. But sodium is essential for nerve and brain health; it is one of the essential components in sending electrical signals between neurons, and life would not be sustainable without adequate amounts of dietary sodium. And, with more types of salt on the market than ever, there is more than just sodium content to consider now. So, what is it about various kinds of dietary salts that we should be concerned with?

TABLE SALT

Table salt is extract from dried up salt deposits, areas where oceans once existed and evaporated to leave only the salt minerals behind. Deposits are collected, rinsed with water to dissolve the salt into solution, and then evaporated under a vacuum. The resulting crystals are then purified and striped of minerals and contaminants in a process that reduces it to primarily sodium chloride. Anti-caking agents such as sodium aluminosilicate, silicon dioxide and magnesium carbonate are added for a more desirable consistency, along with iodine, usually in the form of potassium iodide (KI), an essential nutrient for thyroid and cognitive function. Iodine was originally added as a public health measure to reduce thyroid disorders that were the result of iodine deficiency. Table salt in its final form is usually about 97-98% pure NaCl.

SEA SALT

The evaporation of water from existing oceans gives us the sea salt on the shelves. Sea salt can either be unrefined or refined. Unrefined sea salt maintains its trace minerals, such as potassium, iron, zinc, calcium and magnesium; however, this also means it maintains impurities, which can include trace heavy metals like lead, microplastics, sediment and clay (may impart gray color), algae and marine bacteria. While these all contribute to sea salt’s more complex flavor, the impurities are what raise concern for some. Refined sea salt is washed in a process that is intended to remove trace minerals, clay and sediment, which renders the final product similar in content to table salt, though of a different source. Sea salt tends to be less ground than table salt and thus coarser, leading to a more intense flavor burst, especially when added after cooking. Refinement may result in a flakier product. In general, the darker the sea salt, the more trace minerals and impurities present.

HIMALAYAN PINK SALT

Himalayan salt has risen in popularity over the last decade. This product originates from the Khewra Salt Mine in Pakistan, the second largest salt mine in the world, and will appear pink in color due to its trace iron oxide content. It also contains trace amounts of calcium, iron, potassium, and magnesium, leading to an ever-so-slightly lower sodium content than regular table salt. It is often chosen for its complex flavor, imparted by its wide variety of minerals. There have been reports raising concern for trace amounts of lead in salt, but the content is far from toxic at 100 parts per billion. Lead is a naturally occurring element and thus appears naturally in salt deposits, and with the relatively small amounts of salt we consume, experts don’t believe this raises concern for toxicity.

PURPLE BAMBOO SALT (JUGYEOM)

Purple bamboo salt refers to a traditional Korean method of processing sea salt for medicinal use in which it is roasted at temperatures reaching 2700 F in a clay-lined bamboo case in order to remove impurities. Trace mineral content is also reduced through this process, but a small body of evidence suggests that the salt retains antioxidant and anti-inflammatory properties, which may explain its use as a medicine in Korean tradition.

KOSHER SALT

Kosher salt is often chosen in cooking due to its flaky and coarse texture lending a certain ease to handling. Its formally intended use is as part of the Jewish culinary custom of extracting blood from meat, which the flaky texture seems to do particularly well. Kosher salt also tends to be free of the anti-caking agents & added iodine present in table salt. The fact that a certain salt is kosher unfortunately tells us nothing about its source, however, and kosher salts may be extracted from seawater or evaporated salt deposits, leaving their properties dependent on the method of extraction and processing.

TO SUMMARIZE

Sodium content ends up being equivocal between the various kinds of salts, and, so long as we are primarily getting our salt by adding it to our food and not from processed foods, which have a much higher added salt content, sodium and its effect on blood pressure should not be our greatest concern. As discussed previously, sodium is necessary for many physiological processes.

Unrefined sea salt and Himalayan salt do have trace amounts of beneficial minerals; however, one study suggests these minerals are present in amounts less than 0.5 micrograms (mcg) per gram of salt. Our choice of one salt over another should not rest on this minimal amount of mineral content, particularly if we are eating a diet rich in fruits and vegetables, which are a much better source of minerals like magnesium, calcium and iron.

Table salt has the added iodine content, which is absent from other salt sources. However, we need iodine in relatively small quantities (150 mcg/day) and can obtain sufficient amounts from foods such as fish, dairy, eggs and seaweed.

Arguably, the biggest concern surrounding salt is the presence of microplastics in our sea salt due to ocean pollution. There is increasing evidence that over 90% of sea salt produced around the world is contaminated with microplastics. Plasticizers such as BPA and phthalates are toxic to humans and other animals by disrupting hormonal and metabolic pathways. Microplastics seem to be the primary argument among health experts for choosing one salt over another.

Luckily, we have options: Himalayan salt is mined from ancient sea beds free from pollution, and purple bamboo salt is processed in a way that removes contaminants from sea salt. Though table salt also comes from underground salt deposits, the additives used make it a less clean option.

For your culinary needs, you may prefer one salt’s consistency or flavor over another. But for health reasons, specifically minimizing toxicity, the data currently suggests we should be opting for the Himalayan or Purple Bamboo varieties whenever possible. There are also sea salt companies, such as Jacobsen Sea Salt based in Portland, OR, that use filtration processes which ensure the removal of microplastics.

REFERENCES

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