Your thyroid is a butterfly-shaped gland in your neck that secretes hormones, which regulate growth and development and the rate of your metabolism.

Problems with your thyroid gland and thyroid hormone can impair digestion and absorption of nutrients, disrupt gut function, adversely affect your skin, and have other negative effects on nearly every part of your body.

Thyroid hormone synthesis is controlled by feedback mechanisms that involve communication between your hypothalamus, pituitary, and thyroid glands.

When levels of thyroid hormone are low, your hypothalamus stimulates your pituitary gland to release TSH (thyroid-stimulating hormone), and TSH informs your thyroid gland to make more thyroid hormone.

Production of thyroid hormone requires tyrosine (an amino acid) and iodine. An enzyme, TPO (thyroid peroxidase) works to pull all the ‘pieces’ together to form T4 and T3.

T4 is the major hormone made and secreted by the thyroid gland. About 80% of T4 gets converted to T3 outside of the thyroid gland (mostly in the liver and the kidneys). The enzyme that converts T4 to T3 requires selenium.

Your thyroid can be overactive (hyperthyroid) or underactive (hypothyroid).

There are different causes of hyperthyroidism, and Graves’ Disease is the most common. It occurs when your immune system makes an antibody that stimulates the thyroid leading to higher levels of thyroid hormone.

The most common cause of hypothyroid (low thyroid hormone) around the world is iodine deficiency.

Iodine deficiency in the U.S. today is rare, and hypothyroidism (in the U.S.) is most commonly due to autoimmune processes that attack the thyroid. Autoimmune hypothyroidism is called Hashimoto’s Thyroiditis.

In autoimmune hypothyroid, your body develops antibodies against TPO, the enzyme that builds your thyroid hormones, and/or thyroglobulin, a protein made by your thyroid gland.

In autoimmune hyper or hypothyroidism, excess iodine exposure (usually that comes from supplements) can make the attack on your thyroid gland worse (1,2,3,4,5,6,7). The best way to get iodine is from natural food sources, and not those fortified with it.

If you have autoimmune hyper or hypothyroidism, any autoimmune process involves three factors:

A genetic predisposition
A trigger that turns the gene on
Leaky gut

We can’t change our genes, but we can identify and remove triggers, and address gut health, to slow down, stop, and possibly even reverse the autoimmune process and its destruction.

You can support your thyroid health by eating foods that contain certain nutrients.

Incorporate these nutrients into your diet for thyroid health

Nutrients important for thyroid health: Zinc, selenium, iodine, iron, copper, vitamins A, D, E, B2, B3, B6, B12, and C, turmeric, DHEA, tyrosine

Foods containing nutrients for thyroid health

Zinc: Beef, lamb, pumpkin seeds, lentils, garbanzo beans, quinoa, turkey

Selenium: Brazil nuts, tuna, sardines, salmon, turkey, cod, chicken, lamb, beef

Iodine: Cod, shrimp, boiled egg, navy beans, baked potato with skin, turkey breast, seaweed

Iron (heme iron is found in animal products and nonheme iron is found in some plant foods): Beef, chicken liver, oysters, clams, tuna, mussels, raisins, prune juice, prunes, potato with skin, quinoa, spinach, Swiss chard, white beans, lentils, tofu, hazelnuts, cashews

Copper: Mushrooms (shiitake), nuts (cashews), seeds (sunflower seeds), garbanzo beans, lentils, lima beans, raw kale, oysters, avocado

Vitamin A: Beef liver, cod liver oil, egg, butter, sweet potato, pumpkin, carrot, cantaloupe, mango, spinach, broccoli, kale, collard greens, butternut squash

Vitamin C: All will be higher in vitamin C if uncooked: Bell peppers, papaya, citrus fruits, Brussels sprouts, strawberries, kiwi

Vitamin D: Salmon, herring and sardines, cod liver oil, canned light tuna (lower in mercury), oysters, egg yolk, mushrooms

Vitamin E: Sunflower seeds, spinach, Swiss chard, avocados, turnip greens, asparagus, mustard greens

Vitamin B2: Yogurt, cheese, asparagus, spinach (dark green leafy vegetables), chicken, fish, eggs

Vitamin B3: Chicken, turkey, salmon, canned tuna packed in water, legumes, peanuts

Vitamin B6: Poultry, seafood, bananas, leafy green vegetables (spinach, turnip greens, Swiss chard), potatoes

Vitamin B12: Animal foods are the only natural source of vitamin B12, shellfish, sardines, salmon, tuna, cod, lamb, beef, liver, chicken, fish, eggs, rainbow trout, haddock

Turmeric: Add this anti-inflammatory and antioxidant spice to foods and recipes, and use red and yellow curries

DHEA: Boost DHEA levels with an anti-inflammatory diet, and consume healthy fats and protein sources

Tyrosine: Tyrosine is made in your body from another amino acid, phenylalanine, and it is found in chicken, turkey, fish, beef, lamb, pork, eggs, cheese, peanuts, almonds, pumpkin seeds, lima beans, avocados, and bananas

Avoid High Mercury Fish

High mercury fish: Swordfish, shark, king mackerel, tilefish, marlin, orange roughy, ahi tuna, bigeye tuna, yellowfin tuna

Low mercury fish: Anchovies, catfish, flounder, hake, haddock, herring, salmon (farmed may contain PCBs, not good either), mackerel, canned light tuna, trout, whitefish, pollock, sardines, butterfish

General Recommendations

Go organic when possible for fruits and vegetables.

Go organic, pastured, free-range, grass-fed, wild-caught, etc., for animal products.

Adults, drink at least 6-8 glasses of water per day. Kids, drink one 8 oz glass of water per year of age, per day.

References:

https://www.nejm.org/doi/full/10.1056/nejmoa054022
https://www.ncbi.nlm.nih.gov/pubmed/1345585
https://www.ncbi.nlm.nih.gov/pubmed/9703374
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4192807/
https://www.ncbi.nlm.nih.gov/pubmed/11396708
https://pmj.bmj.com/content/postgradmedj/62/729/661.full.pdf
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3976240/