Print
What Every Self-Sufficient Family Needs to Know Before Switching To “Natural” Salt
There’s a good chance the salt shaker on your farmhouse table is quietly doing something you’ve never thought twice about. Iodized salt — that plain, cheap staple next to the pepper — may be the most consequential public health tool in American history. And right now, as more folks ditch it for fancy sea salt and kosher salt, a slow, invisible crisis is creeping back.
The Enemy Nobody Saw Coming
Before we talk about what iodine does, picture what it looks like when you don’t have enough of it. Imagine walking into a Swiss mountain village in the early 1900s. Men with necks swollen to the size of cantaloupes work the fields.
Children who can’t hear or speak sit quietly in the corners of stone farmhouses. Mark Twain visited Switzerland around that time and wrote, “I am satisfied. I have seen the principal features of Swiss scenery, Mont Blanc and the goiter. Now for home.” In some remote regions, 94% of men had goiters. As many as 1 in 10 babies showed signs of cretinism — a severe condition involving physical stunting, deafness, muteness, and intellectual disability.
Right here on American soil, the picture wasn’t much better. The entire northern strip of the U.S. — stretching across Michigan, Minnesota, and the Great Lakes states — was nicknamed the Goiter Belt.
In 1917, more than 20,000 men in northern Michigan couldn’t button their military uniforms because their necks were too swollen. Goiter was the single biggest reason men were disqualified from serving in World War I. School surveys in the region found goiter rates in children of 70 to 100%.
The Glaciers Did It
Here’s what nobody around the campfire ever tells you: glaciers are the villain of this story.
During the Ice Age, retreating glaciers scraped away hundreds of meters of mineral-rich topsoil across the upper Midwest and Switzerland, stripping the land of iodine. Every crop grown in that soil, every animal that grazed it, every well drawing from beneath it — all were quietly iodine-poor.
People didn’t know it. They just got sick.
That’s the thing about iodine. It’s element 53 on the periodic table and the heaviest element required for biological life. Your thyroid — that butterfly-shaped gland sitting right at the base of your throat — depends on it completely.
The thyroid’s entire job is to produce two hormones, T3 and T4, which regulate how every cell in your body burns energy. The “3” and “4” literally stand for the number of iodine atoms packed into each hormone molecule. No iodine, no hormones. No hormones, the pituitary gland keeps hammering the thyroid to try harder and harder — and the gland grows trying to catch every last iodine atom drifting through the blood. That growth is a goiter.
Goiters, though, turn out to be the least of the damage. The real tragedy strikes in the womb.
A developing baby’s brain and body are shaped almost entirely by the mother’s thyroid hormones in the first half of pregnancy — the baby’s own thyroid doesn’t even switch on until about halfway through. When a pregnant mother is iodine-deficient, her T3 and T4 levels fall short, and the baby’s brain pays the price.
That’s cretinism. And for generations, rural and inland communities had no idea that something as simple as a mineral in their soil was behind it all.
Two Doctors and a Snow Shovel
The breakthrough came from unlikely heroes — not big pharmaceutical companies, not government agencies, but two humble family doctors in Switzerland.
Just before the winter of 1918, Dr. Otto Bayard traveled to a remote, goiter-ravaged village and used a snow shovel to hand-mix potassium iodide into salt for five families. The mountain pass closed for winter before he could get back. When spring thawed the roads, he returned to find no one harmed and every goiter gone. He quickly expanded the experiment to over 1,000 people for six months with the same results.
By 1922, a commission of Swiss health leaders began nationally iodizing salt. They chose salt for brilliantly practical reasons: it’s a rock mineral — it doesn’t spoil, it isn’t seasonal, it’s dirt cheap to produce in massive quantities, and humans eat roughly the same amount of it consistently. It was the perfect delivery vehicle.
Meanwhile, Michigan doctor David Cowie caught wind of the Swiss success. He organized nearly 200 lectures across the state, speaking to 26,000 people, and convinced local salt producers to get on board. On May 1, 1924, iodized salt appeared on Michigan shelves for the first time. Morton Salt soon took it nationwide.
The results were swift and staggering.
180 Million IQ Points
Within a decade, goiter rates in Detroit-area children dropped over 90%. In Switzerland, deaths from cretinism collapsed from 1 in 600 births to 1 in 3,000.
Since 1930, there hasn’t been a single documented case of a Swiss child born with cretinism. And that was just the beginning of what researchers would eventually uncover.
In 2013, economists at the National Bureau of Economic Research published a landmark study comparing 2 million American men born before and after iodization — made possible because the WWII draft happened exactly 18 years later.
In the 25% most iodine-deficient regions of the country, men born after iodization scored a full standard deviation higher on military cognitive tests. That’s roughly 15 IQ points. Averaged across the entire population, iodization added an estimated 3.5 IQ points per person — totaling around 180 million added IQ points for that generation of Americans alone. All for about 5 cents per person per year.
The Crisis Coming Back Around
Here’s where it gets uncomfortable for those of us in the homesteading world: iodine deficiency is quietly making a comeback in America — and it’s partly driven by the exact foods many health-conscious folks have embraced.
Median iodine levels in the U.S. have fallen roughly 50% over the last 50 years. The primary culprit? Dairy consumption is dropping.
Nearly half of Americans’ iodine intake historically came from dairy — not because milk is naturally loaded with it, but because iodine-based sanitizers were used to clean cows and milking equipment, and trace amounts mixed into the milk. As dairy alternatives like almond and oat milk have surged in popularity, that iodine pipeline quietly shut off. Those plant-based milks contain essentially no iodine.
And then there’s the salt issue. Only 53% of U.S. table salt is iodized today.
Iodized salt is almost never used in processed foods — manufacturers worry it might affect color or taste, or that the name “potassium iodide” will scare customers. Meanwhile, America’s Test Kitchen–style chefs have spent years telling audiences to throw away their table salt and reach for sea salt or kosher salt. Neither contains iodine.
The group hit hardest? Pregnant and breastfeeding women — the ones who need iodine most. Recent NHANES data from 2011 to 2020 shows that median iodine levels in pregnant American women have already fallen below the WHO’s recommended threshold. Prevalence of inadequate iodine status in pregnant women now ranges between 23% and 59%, depending on the study. That’s not a fringe number.
That’s potentially half of all pregnant mothers in America today walking around quietly iodine-deficient — with real downstream effects on their babies’ developing brains.
What It Means for Your Homestead
If you’re growing your own food on land that hasn’t seen an ocean in 10,000 years — which is true of much of the rural Midwest and mountain West — your soil is almost certainly iodine-poor. Your garden vegetables and your pasture-raised eggs aren’t going to make up the gap. Seaweed is the richest food source of iodine on Earth, but few rural families eat it regularly.
The fix is almost laughably simple: use iodized salt. Not fancy finishing salt on your steak — iodized table salt, used regularly in cooking and food preservation.
For those who are pregnant, breastfeeding, or raising young children, doctors note it’s worth being intentional. And for anyone who’s switched entirely to sea salt, kosher salt, or Himalayan pink salt — which contain no meaningful iodine — it’s worth reconsidering.
The people who lived in the Goiter Belt before 1924 weren’t unhealthy because they were weak or careless. They were iodine-deficient because their land, their water, and their food gave them no other choice.
The iodized salt revolution saved them. It would be a tragedy to walk away from that lesson… one shaker at a time.
For more on iodine and thyroid health, see the 2013 NBER study on iodization and IQ here, the NIH’s PMC article on cognitive effects of micronutrient deficiency here, and recent research on the resurgence of iodine deficiency in American women here.
