Our bodies, when functioning properly, are amazing machines. In order for that machine to function properly, there are several essential ingredients. Oxygen, of course, along with water, protein, essential fatty acids, and several other nutrients.
Iodine likely isn’t one of the first essential nutrients that comes to mind, but our bodies couldn’t function without it. It regulates thyroid function, which impacts body temperature, metabolism, growth, red blood cell production, muscle function, and more.
Iodine deficiency was a common problem in what was once called the “goiter belt” in the United States. This area included the Upper Midwest and Great Lakes states where iodine is deficient in the soil and plants. Iodine deficiency in adults leads to a condition called “goiter”, in which the thyroid gland swells to a noticeably large size. Significant iodine deficiency during pregnancy and childhood has more severe consequences for the child, leading to severe and irreversible stunting of mental and physical development.
One of the great victories of nutrition in public health was the widespread iodization of salt. This movement began in the United States and Switzerland in the early 1920’s after physicians discovered the impact of goiter symptoms disqualifying young men from serving in the military during World War I. Although it took a few decades to become common practice, over 90% of homes in the United States now use iodized salt. With that change, the prevalence of goiter has fallen dramatically in the population. Other countries have added iodine to bread and drinking water as well, although it should be noted that excess intake of iodine can also negatively affect thyroid function.
Iodized salt is now the main source of iodine in the American diet, although it can also be obtained naturally from plant foods grown in iodine-rich soil as well as seafood from the ocean. Seaweed is a particularly rich source of iodine, as most of the iodine in the world is found in the oceans.
If you’re a fan of the trendy Himalayan pink salts and other “natural” salts, you may want to avoid making it your primary salt of choice; they are far lower in iodine than standard iodized salts.
So if you’ve ever wondered what the purpose of iodized salt is…now you know!