Recent health claims have made sea salt a popular choice for consumers, despite the similarities in nutritional value between sea salt and table salt.
“Sea salt is very popular right now, but consumers need to know that both contain sodium and that means both can raise blood pressure,” said Susan Mills-Gray, Nutrition/Health specialist with University of Missouri Extension.
Sea salt is harvested from seawater through evaporation. It is available in fine or coarse grain and has a slightly different taste than table salt because of the different minerals it contains. Most sea salts don’t contain iodine or any other additives. However, sea salt does have impurities like the tiny bits of clay that give gray sea salt its color or the iron-rich red volcanic clay added to Hawaiian sea salt.
Table salt is typically from rock salt, which is mined from mineral deposits. It is a fine-grained salt that often contains added iodine, which is necessary for normal thyroid function. Most table salts also contain an anti-caking ingredient.
Since the underground salt deposits that produce most table salt are the result of evaporating seawater or salty lakes, the chemistry of the two are very similar. Both rock salt and sea salt contain sodium chloride, and other minerals like calcium, potassium and magnesium sulfates. However, when a large body of water evaporates, the chemicals in it precipitate out in stages — calcium compounds get deposited first, then sodium, then magnesium and potassium. Because of this, a rock salt deposit is often a more pure mass of sodium than what you get by drying out sea salt. Since rock salt for human consumption is typically processed to remove grit and other impurities, by the time it reaches the table it is almost pure sodium. The additional minerals and impurities in sea salt dilute the sodium levels slightly.
If you favor foods with fewer additives, you may prefer sea salt — but there’s no evidence that the additives in table salt are harmful to your health. Although your body needs some sodium to function properly, most people eat too much, which can lead to high blood pressure. No matter what kind of salt you use, most experts recommend limiting sodium between 1,500 and 2,300 milligrams daily. Based on much research, experts also believe that 1,200 milligrams or less a day is best for lowering high blood pressure. One teaspoon of table salt contains about 2,400 milligrams of sodium, while one teaspoon of sea salt has about 2,250 milligrams.
“From a cooking perspective the main difference is texture and taste. Table salt is very fine which makes it easy to dissolve. Sea salt is coarser and adds a bit of crunch and flavor difference due to the mineral and impurities content,” said Mills-Gray.
“Sea salt and table have similar nutritional value and basically salt is salt when it comes to increasing chronic disease risk,” she said.