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Are You Eating Enough Iodine-Rich Foods?

By Jillian Levy, CHHC

September 14, 2020

Original article and page source found here.

Iodine is considered one of the body’s vital nutrients, responsible for regulating thyroid function, supporting a healthy metabolism, aiding in growth and development, and preventing certain chronic diseases. Unfortunately, many adults don’t consume enough iodine-rich foods and, thus, suffer from an iodine deficiency.

Therefore, many suffer a range of negative health consequences as a result, known as iodine deficiency disorders.

Iodine is present throughout the body in just about every organ and tissue, needed by almost every bodily system to keep us alive and energized. For this reason, iodine deficiency poses many risks — an alarming thought considering that some sources suggest around 50 percent or more of the adult population in Western developed nations are at least somewhat iodine-deficient.

That’s why eating iodine-rich foods is so vital.

What Is Iodine?

Iodine is an essential mineral that enters the body through iodine-rich foods, including certain salts (“iodized salt”), eggs, sea vegetables, fish, beans and other foods. It’s found naturally in mineral-rich soils and also ocean water.

Iodine present in foods and iodized salt contains several chemical forms of iodine, including sodium and potassium salts, inorganic iodine (I2), iodate, and iodide. Iodine usually occurs as a salt and is called iodide when it does (not iodine).

We rely on iodine to create thyroxine (T4 hormone) and triiodothyronine (T3), two of the main hormones produced by the thyroid that control numerous important functions.

Iodide is absorbed in the stomach and enters the bloodstream, circulating to the thyroid gland, where it uses appropriate amounts for thyroid hormone synthesis. The unused iodine that we get from iodine-rich foods is then excreted in the urine.

A healthy adult usually has about 15–20 milligrams of iodine present within her body at one time — 70 percent to 80 percent of which is stored in the thyroid.

What is one of the most widespread symptoms of iodine deficiency? Thyroid disorders.

Thyroid function relies on proper levels of iodine, so too much (or too little) can cause many serious health problems.

Wondering, “How can I increase my iodine levels?” The very best way to maintain a normal iodine status is by eating foods high in iodine.

Related: Dulse: The Beneficial Seaweed that Tastes like Bacon!

Top 15 Iodine-Rich Foods

What foods are high in iodine? Here are the best foods with iodine, according to the U.S. Department of Agriculture, with percentages below based on the recommended dietary allowance for the average adult:

  1. Dried kelp — 1 whole sheet dried: 19 to 2,984 micrograms (amounts vary widely — anywhere from 11 percent to 1,989 percent)

  2. Iodized salt — 1.5 grams/approx. ¼ teaspoon (71 percent DV)

  3. Cod (wild-caught) — 3 ounces: 99 micrograms (66 percent DV)

  4. Yogurt (organic, grass-fed and ideally raw) — 1 cup: 75 micrograms (50 percent DV)

  5. Dried wakame — 66 micrograms per gram (44 percent DV)

  6. Grass-fed milk — 1 cup: 56 micrograms (37 percent DV)

  7. Dried nori — 16–43 micrograms per gram (up to 29 percent DV)

  8. Eggs — 1 large: 24 micrograms (16 percent DV)

  9. Tuna — 1 can in oil/3 ounces: 17 micrograms (11 percent DV)

  10. Lima beans — 1 cup cooked: 16 micrograms (10 percent DV)

  11. Corn (organic) — 1/2 cup: 14 micrograms (9 percent DV)

  12. Prunes — 5 prunes: 13 micrograms (9 percent DV)

  13. Cheese (look for raw, unpasteurized) — 1 ounce: 12 micrograms (8 percent DV)

  14. Green peas — 1 cup cooked: 6 micrograms (4 percent DV)

  15. Bananas — 1 medium: 3 micrograms (2 percent DV)

The ocean is considered the prime provider of iodine‐rich foods, such as seaweeds, including kelp, hiziki, kombu, nori, arame and wakame. Kelp seaweed contains the highest amount of iodine among all foods.

Other good sources include cheddar and mozzarella cheeses, along with grass-fed butter (almost all dairy products contain some iodine), sardines, scallops, shrimp and other types of seaweeds.

What vegetables are high in iodine? As you can see above, some of the top vegetable sources include green beans and peas. Organic/non-GMO corn, leafy greens, onions, sweet potatoes, many legumes/beans, nuts, seeds, and whole grains like barley are also iodine-rich foods.

Do bananas have iodine? Yes, although they do not contain as much as dried fruits like prunes and raisins.

Berries, including strawberries, also contain some.

Keep in mind that iodine levels vary greatly within a type of food depending on the conditions in which it was grown or produced. For example, because soil depletion is a concern for lowering iodine counts in foods, crops grown in depleted soils have lower levels of iodine than organically grown crops.

Similarly, wild-caught seafood and cage-free, organic eggs are more likely to contain higher levels of nutrients than farm-raised fish or conventionally produced versions.

Related: What Is Samphire? Surprising Benefits and How to Cook It

Iodine Health Benefits

1. Supports Thyroid Health

The thyroid must have high enough levels of iodine present in order to make key hormones, including thyroxine.

Thyroid hormones regulate many important biochemical reactions every day. Some of the most significant include the synthesis of amino acids from proteins, digestive enzyme activity, and proper skeletal and central nervous system development.

When thyroid disorders such as hypothyroidism occur because of a diet low in iodine-rich foods, symptoms can range from a sluggish metabolism to heart complications, changes in appetite and body temperature, alterations in thirst and perspiration, weight fluctuations, and mood changes.

Acquiring enough of this mineral is also important for preventing goiters, or an enlarged thyroid, as well.

2. May Help Prevent Cancer

Iodine improves immunity and helps induce apoptosis — the self-destruction of dangerous, cancerous cells. While it can help destroy mutated cancer cells, it doesn’t destroy healthy cells in the process.

For example, evidence shows the ability of iodine-rich seaweed to inhibit certain types of breast tumor development. This is supported by the relatively low rate of breast cancer in parts of the world like Japan, where women consume a diet high in seaweed.

Specific types of iodine treatments are also sometimes used to help treat thyroid cancers.

3. Supports Growth and Development in Children

Iodine is most critical in the early stages of development, as a fetus’ brain tissue and thyroid receptors are extremely dependent on this mineral to form normally.

Research shows that an iodine deficiency during pregnancy and infancy can disturb healthy growth and brain development. Infants with iodine deficiency are more susceptible to mortality and at a higher risk for neurodegenerative problems — like a form of mental disability known as cretinism — low growth rate, motor-function problems and learning disabilities.

Although doctors commonly test women during pregnancy for iodine deficiency, it’s difficult to get an accurate reading of iodine levels. Thus, many health experts now encourage women to increase their intake of iodine-rich foods in their pregnancy diet and supplement with iodine considering how common deficiencies are.

4. Maintains Healthy Brain Function

Studies show that iodine plays a role in healthy brain development and ongoing cognitive abilities — therefore deficiency is thought by experts to be one of the most common preventable causes of mental disorders in the world, as well as neurodegenerative impairment.

Some of the ways that it supports cognitive health include by facilitating brain development during specific time windows influencing neurogenesis, neuronal and glial cell differentiation, myelination, neuronal migration, and synaptogenesis.

5. Preserves Skin Health and Fights Infections

A common sign of iodine deficiency is dry, rough and irritated skin that becomes flaky and inflamed. This mineral also helps regulate perspiration, so people might experience changes in how much they sweat if their levels become imbalanced.

Another benefit is potentially helping to treat minor infections, such as those that form in scrapes, when applied topically since it has natural antibacterial properties.

6. Helps Control Sweating and Body Temperature

Sweating is an important detoxification method that the body uses to discard toxins and even excess calories. Iodine deficiency can disturb the natural way we flush waste from the body through our pores and control our body temperatures.

Similar to an ability to produce enough sweat, a lack of iodine also can cause dry mouth due to an abnormally low production of saliva. This makes it difficult to enjoy eating and can impair digestion to some degree.

Iodine Deficiency

Worldwide around 2 billion people are estimated to suffer from insufficient iodine intake, although many are unaware because they don’t display symptoms. Populations in South Asia and sub-Saharan Africa are particularly affected.

In the U.S. and Europe, deficiency is believed to be on the rise.

Common signs of an iodine deficiency include:

  • Trouble producing saliva and properly digesting food