Salted_ A Manifesto on the World's Most Essential Mineral, With Recipes - Mark Bitterman [23]
BEHIND THE IODIZED CURTAIN
Adults need about 150µg of iodine per day, which totals up to one teaspoon in a 120-year lifetime. Ideally, we receive sufficient iodine from the food we eat. It is abundant in all seafood and is also present in vegetables, except where soils are naturally low in iodine, such as in the Himalayas, the Andes, and the Great Lakes region of the United States. The World Health Organization estimates that 740 million people in the world suffer from iodine deficiency disorders (IDD): mostly preschool children and pregnant women in low-income countries. IDDs include goiter, stillbirth, and thyroid problems. The most common disorder is mental retardation in children. One study found IQ scores in iodine-deficient communities to be ten to fifteen points lower than iodine-replete ones. The addition of iodine to salt in the form of potassium iodide, potassium iodate, sodium iodide, or sodium iodate has proven highly effective in the prevention of iodine deficiency.
The push for mass iodization of salt is not the result of iodine being stripped from natural salt. Rather, it is because salt has been selected as a preferred delivery vehicle for iodine supplementation. Advocates of salt iodization argue that it costs merely pennies to iodize the salt for a single person for a whole year, making it a miraculously inexpensive (about $0.05 per person per year) way to improve public health. Any food could be artificially iodized (iodized bread, milk, and water were common in the twentieth century), but salt was chosen because everyone consumes it, levels of consumption are more or less the same across populations, iodization techniques for salt are inexpensive, and salt production is consolidated in the hands of just a few producers, making it easy to implement. That said, salt is hardly a perfect vehicle for artificial iodization. Humidity volatizes iodine in stored salt, and iodine content has been found to vary threefold from one container or brand to another.
Iodization does not harm salt, but it has incited a sense in some people that their health may be at risk without iodized salt. Iodide is found in trace amounts in unrefined salts, but generally not in nutritionally sufficient quantities. But iodine never was a significant nutrient in salt. Fixating on its absence as a health risk distracts us from the real nutritional depletion done to industrial harvested salt during its production and processing, and it has aided and abetted in the standardization of salt as a food. Iodized salt may indeed have its place as a strategy for improving health in various parts of the world, but the wholesale embrace of iodization ignores the broad negative impact on global health of promoting centralized, industrialized food production.
Those with access to fresh and frozen foods can satisfy their needs for dietary iodine by eating two servings of seafood a week. Kelp is particularly rich in iodine, as are vegetables grown in many parts of the world. Iodized salt is also used in many prepared and processed foods. Those wishing to supplement their diet without resorting to iodized salt can take a natural kelp-based supplement such as Liqui-Kelp or Liqui-Duls, which costs only a penny a day.
Industrial manufacturing depletes salt of most of its natural minerals. And yet, chemical engineers have managed to bulk up industrial salt with plenty of additives. Most important from a manufacturing standpoint, refined salts have all the moisture taken out of them, which makes them thirsty and gives them the tendency to clump as they pull moisture from the atmosphere. To combat clumping, anticaking agents are added. These agents are often aluminum-based compounds, either sodium aluminosilicate or sodium