Maine’s seaweed and your thyroid health

The problem of iodine deficiency has made a comeback, but Maine’s emerging seaweed aquaculture could be a solution.

In the 1920’s iodine was added to table salt because iodine deficiency was widespread in the U.S. and especially concentrated in the Great Lakes, Northwest, and Appalachian regions. Iodine is a key element needed to produce thyroid hormones that control important physiological functions like metabolism, heart rate, and body temperature.

Iodized salt has continued to be the primary source of iodine in the industrialized world, however the backlash against sodium has led to a decline in salt consumption over the years, and more people are using sea salt, which usually isn’t iodized. Further losses largely due to discontinuing iodine’s use as an additive in commercial food products has once again caused iodine deficiency to become endemic.

It’s estimated that about 40 percent of the world’s population is at risk of developing iodine deficiency, and in the US pediatricians are concerned that many women of reproductive age are not getting enough iodine in their diets.

The thyroid gland produces thyroid hormones composed of the amino acid tyrosine linked, or iodinated, with atoms of iodine. Too little thyroid hormone (hypothyroidism) results in a slowed heart rate, colder body temperature, weight gain, dry skin, hair loss, weakness, muscle aches, fatigue, and neurological dysfunction like depression.

If the thyroid gland does not get enough iodine, it just keeps making inactive thyroid hormones that remain locked within the gland, unable to leave and enter the circulation without the iodination step. The thyroid can enlarge so much that a visible swelling at the base of the neck called goiter can develop.

In severe cases people with hypothyroidism experience cognitive decline, but most troubling is hypothyroidism in infants. Thyroid hormone is required for the development and maturation of the brain, and babies born to mothers with inadequate iodine levels are at risk of irreversible mental retardation known as congenital hypothyroidism or cretinism.

In comes seaweed

Of all food sources seaweed contains the largest source of iodine by far. To call the lovely sea vegetable a weed is a misnomer, I feel, conjuring images of shriveled, useless muck lying on the beach. Seaweed is actually a diverse group of flora comprised of thousands of marine algae.

On a large scale seaweed is harvested in the U.S. for use in fertilizers and industrial additives like carrageenan that thicken and stabilize items like shampoo, drinks, and ice cream. But, perhaps Americans can embrace seaweed as Asian cultures do, incorporating it more regularly into their diets, instead of enjoying it occasionally at Japanese restaurants. 

A Mainer named Tollef Olson is the first to bring seaweed farming — already a huge 5-billion dollar industry outside the US — to the United States, and he’s doing it in Casco Bay.

A video produced by the Portland Press Herald on YouTube gives a look at what he does:

Wild seaweed harvesting is not always sustainable, as over harvesting can harm the habitats that seaweed fosters. Olson is demonstrating that seaweed can be grown sustainably offshore in large amounts. “We’re farming what’s arguably the healthiest vegetable you can eat using no arable or tillable land; we use no fresh water, we add no fertilizer, we use no herbicides, the plant sequester [carbon dioxide] releasing oxygen which can help nullify acidification. It’s a win, win, win way to grow food,” he says in the video.

And, forget about purchasing multivitamins (that can be contaminated with chemicals and synthetic materials), seaweed isn’t just a great source of iodine, “It’s also loaded with other trace elements and minerals,” he said in an interview with WMPG.

“I used to say it had a couple dozen, but a doctor friend of mine laughed and said, ‘No, it has all the minerals and trace elements, humans are made of the same elements and minerals that the ocean is.’”

You might be thinking, “If I’m trying to avoid sodium, why would I want to eat a plant that grows in salt water?” Yes, when seaweed is harvested and immediately dried the sodium concentrates and the end product can be quite salty. However, as Olson explains on his website, if seaweed is blanched and frozen the result is mild with “just a hint of ocean.”

I hope that this emerging trend in sustainable aquaculture takes off. It’s a great way to make use of America’s vast coastline while encouraging health, for us and the environment.

For more reading:

Iodine Deficiency

History of U.S. Iodine Fortification and Supplementation

The Seaweed Site: information on marine algae