How Inflammation Causes Hypothyroidism

Inflammation is at the core of most chronic illnesses including hypothyroidism and Hashimoto’s disease. But how exactly does inflammation cause hypothyroidism? Nonthyroidal illness syndrome (NTIS) is the state in which inflammation causes negative changes to thyroid hormone including low T3 and increased reverse T3 (rT3). T3 is the most active form of thyroid hormone and rT3 actually blocks T3 receptors so inflammation can really knock out thyroid function. TSH levels however stay relatively “normal” in NTIS thus leaving many patients with the symptoms of hypothyroidism but no diagnosis since no one is checking their T3 or rT3 levels.

In this article I’ll be referencing a paper entitled, “IL-6 promotes nonthyroidal illness syndrome by blocking thyroxine activation while promoting thyroid hormone inactivation in human cells.”

How Inflammation Causes Hypothyroidism

T4 is normally converted into the more active T3 under normal conditions but when you’re chronically inflammed, the enzymes that perform this conversion may not be functioning properly. The “4” in T4 indicates that it has 4 iodine molecules and the “3” in T3 indicates that it has 3 iodine molecules. There are three enzymes called deiodinases involved in this process:

  • D1 converts T4 into T3 by removal of one iodine from T4 to make T3.
  • D2 does the same thing as D1.
  • D3 inactivates both T4 and T3 but also increases rT3.

80% of the T3 in your body comes from D1 and D2 converting T4 into T3. Inhibition of D1 and D2 due to inflammation is the most common cause of low T3 but D3 is also a contributing factor to low T3 and increased rT3.

What is inflammation?

Inflammation is basically an overactive immune response that is acute or chronic. This overactive immune response can result in tissue damage if it is localized to a specific area in the body or it can be present throughout the entire body resulting in various symptoms such as fatigue, brain fog, joint pain, digestive problems and much more. There really aren’t any symptoms I could list that aren’t related to inflammation.

If you have elevated C-reactive protein levels on your blood tests then this can indicate inflammation. I test all of my patients for this marker to see their level of inflammation. Cytokines are chemical messengers in your body that communicate with your immune system in response to any kind of stress. Interleukin 6, or IL-6, is a well-studied cytokine that is elevated when there is inflammation and it has been specifically studied in relation to thyroid hormone. Increased levels of IL-6 have been shown to lower T3 levels and increase reverse T3 levels.

What causes inflammation?

Many things can cause inflammation and some of these tend to be overlooked. Here is a list to think about if you have hypothyroidism or Hashimoto’s disease:

  • Stress-both physical and emotional
  • Infections of all types ie. viruses, bacteria, parasites, yeast
  • Food sensitivities ie. gluten, dairy etc.
  • Loneliness
  • Social isolation
  • Lack of meaningful purpose in life
  • Lack of sleep
  • Lack of exercise or excessive exercise
  • Relationship conflicts
  • Gut dysbiosis
  • Dental infections
  • Autoimmunity
  • Lack of physical affection
  • Environmental toxins

Some of the above may surprise you but all of these need to be seriously confronted if they are present.

What did the above study find on inflammation and hypothyroidism?

When the authors subjected cells to the inflammatory cytokine IL-6, both D1 and D2 activity decreased thus resulting in low T3 and increased rT3 levels. Additionally, D3 activity increased thus lowering T3 levels even more and increasing rT3. It was clear that inflammation significantly disrupts thyroid hormone in the peripheral tissues of the body. This means that your thyroid may be producing healthy levels of thyroid hormone but once it leaves the thyroid and is supposed to be activated in other organs such as the gut, liver, kidneys etc., it may not do so optimally.

There was a very interesting finding which showed that N-acetyl cysteine actually blocked the negative effects of IL-6 thus preventing decreases in T3 and increases in rT3. N-acetyl cysteine, or NAC, increases glutathione levels and glutathione levels are decreased in inflammation. Glutathione is also required for proper D1, D2, and D3 function so increasing levels of glutathione can ensure proper conversion of T4 to T3 and a reduction in rT3.

I use NAC quite a bit in my patients with hypothyroidism and Hashimoto’s disease because it not only does the above, but it also protects the thyroid gland from damage due to inflammation. Additionally, NAC helps to balance the immune system in autoimmunity and it’s also great for chronic infections such as the Epstein-Barr Virus and Helicobacter pylori.

I like the 700mg NAC product from Moss Nutrition taken 1 capsule once or twice a day with food in patients with hypothyroidism and Hashimoto’s disease. Some people will have a bad reaction to NAC because of its sulfur content or because their gut microbiota is out of balance. Additionally, NAC is going to enhance detoxification which is not the right thing for some people. NAC definitely isn’t for everyone so be sure to take it under doctor supervision or you may have side effects if used at the wrong time.

N-Acetyl Cysteine Hypothyroidism and Hashimoto's Disease

How else can you increase glutathione levels?

1. Eat plenty of suflur-rich foods such as meat, fish, eggs, onions, garlic, and cruciferous vegetables like broccoli, Brussels sprouts, cauliflower, kale, and mustard greens.

2. Avoid drinking alcohol which depletes your body of glutathione.

3. Optimize your sleep to get 7-9 hours of uninterrrupted rest.

4. Exercise improves glutathione but don’t overdo it or you’ll actually deplete your glutathione levels.

5. Increase your vitamin C intake by eating plenty of fruits and vegetables or supplement with 500-1,000mg a day.

6. Eat selenium-rich foods such as beef, chicken, fish, organ meats, cottage cheese, brown rice and Brazil nuts. Brazil nuts can be highly variable in their selenium content so I don’t recommend them more than once a week.

7. Consume a high quality whey protein supplement like Select Whey from Moss Nutrition available in unflavored or vanilla flavor. Whey protein is rich in the amino acid cysteine which is required for glutathione production.

8. Use turmeric in your cooking and take a curcumin supplement like CurcuSelect by Moss Nutrition which has the patented Meriva curcumin for best absorption.

9. Try a Milk Thistle supplement which has been shown to boost glutathione levels.

You’ll most likely be able to maintain healthy glutathione levels from the food that you eat but you can always add in some of the above recommendations if you’re very ill and need more support. Healthy glutathione levels will ensure your T4 is properly converted into T3 while minimizing reverse T3 levels.

Putting it all together

It is clear that inflammation disrupts healthy thyroid hormone levels so the real key is finding the source of your inflammation and addressing it. Review the above list and be sure you’re working with a functional medicine practitioner who will adequately investigate each potential source.

If you have a chronic infection like Epstein-Barr Virus then you need the right healing plan to get it under control. Or if your gut is out of balance then you need a good plan for optimal gut health. You can immediately begin some of the strategies listed above for ensuring healthy glutathione levels which may help improve your T3 and rT3 levels. Your thyroid issues may simply be due to undiagnosed sources of inflammation so have these thoroughly investigated and you may be on your way to optimal thyroid health.

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