Thyroid Health

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Understanding Thyroid Antibodies: Why Is My Thyroglobulin Antibody High?

Written by Dr. Michael Ruscio, DC on December 24, 2021

Written by Dr. Michael Ruscio, DC on December 24, 2021 — Reviewed by Dr. Hannah Hamlin

Thyroid Autoimmunity and the Importance and Limitations of Elevated Thyroid Antibodies 

• Why Is My Thyroglobulin Antibody High?|
• Conditions That May Raise Thyroglobulin Antibody Levels|
• Other Thyroid Antibodies|
• 4 Ways to Reduce Thyroid Antibodies|
• Final Thoughts|

If a recent lab test showed that you have elevated thyroglobulin antibodies, your next question might be “why is my thyroglobulin antibody high?” and, “How can I bring it down to a normal level?” However, when it comes to thyroid antibodies, striving for perfection may be overrated. Elevated levels of thyroid antibodies do not necessarily correlate with your thyroid health or symptoms. 

Thyroglobulin antibodies are notoriously difficult for health care providers to interpret and for patients to understand. Often the level of antibody that is produced does not correlate with clinical hypothyroidism or symptom control.

In this article, we will break down the importance of thyroid antibodies including thyroglobulin and thyroid peroxidase antibodies (TPO), when elevated levels actually matter, and what you can do about it.

I Found Out My Thyroglobulin Antibody Is High. Now What?

Despite thyroglobulin (TG) antibody levels showing a correlation with thyroid health, research supports that they are not a strong predictor of thyroid disease. There are much more reliable tests for diagnosing Hashimoto’s thyroiditis, such as TPO-antibodies, TSH levels, and thyroxine levels. 

Hashimoto’s thyroiditis is a common autoimmune condition that causes the immune system to attack the thyroid gland. In some cases, this leads to hypothyroidism, however this is much less common than many people assume (only about 9-19% of Hashimoto’s patients ever develop hypothyroidism). 

Hashimoto’s is diagnosed by several thyroid function tests, such as 1:

• Elevated thyroid stimulating hormone (TSH) levels.
• Low thyroid hormone levels, reported as free or total T3 and T4
• Elevated thyroid peroxidase (TPO) antibodies
• Elevated thyroglobulin (TG) antibodies 
• Elevated TSH antibodies 

While TPO-antibodies are more indicative of Hashimoto’s thyroiditis, elevated anti-TG antibodies are often reported on lab results, creating concern for patients. 

A 2019 study found that anti-TG antibodies are elevated in 60-80% of patients with Hashimoto’s thyroiditis and in 40-60% of those with Grave’s disease. However, the presence of thyroglobulin antibodies showed only a low-to-moderate sensitivity in diagnosing autoimmune thyroiditis. Additionally, they were not useful in identifying when a patient has transitioned from subclinical to overt hypothyroidism (when hypothyroidism is visible on lab results) 2.

Thyroglobulin antibodies can even be incidental findings in patients with normal thyroid function 2. This means that patients with no other laboratory signs or physical symptoms of thyroid disease can have elevated thyroglobulin antibodies.

It is no wonder that these elusive antibodies cause so much confusion to health care providers and patients. 

What Are Thyroid Antibodies?

Antibodies are not inherently bad and are actually a very important part of our immune system. When the body detects foreign pathogens, such as bacterial or viral infections, it produces proteins called antibodies. These proteins help recruit other immune cells and fight off intruders. 

However, in some people, the immune system goes awry and starts to produce antibodies against normal body tissue. In the case of thyroid autoimmune disorders, like Hashimoto’s hypothyroidism and Grave’s disease, the immune system mistakenly produces antibodies that attack the thyroid cells.

When they go unchecked, these antibodies can lead to inflammation in the thyroid — known as “thyroiditis.” This destruction to the gland may eventually cause the person to enter a hypothyroid or hyperthyroid state. 

Not everyone who has antithyroid antibodies is hypothyroid, but some people with elevated TPO, TSH, or TG antibodies will eventually become hypothyroid. Furthermore, some patients with thyroid disease may never show elevated levels of any thyroid antibodies 1. 

Certain Conditions Can Make Your Thyroglobulin Antibody High

Even though antithyroglobulin antibodies are not the best predictor of thyroid disorders, they should not necessarily be ignored. Unlike TPO antibodies, thyroglobulin antibodies are not able to stimulate an immune response in the thyroid, but they may be useful in diagnosing certain thyroid conditions 2 3.

Anti-TG antibody levels may show importance in the following:

• Patients diagnosed with thyroid carcinoma who have elevated TG antibodies may be at a higher risk of the cancer spreading to lymph nodes or surrounding organs. Elevated levels may also indicate a high risk of thyroid cancer recurrence after treatment 4.
• Breast cancer patients may also have high thyroglobulin antibody test results 4.
• Elevated TG-antibodies may have a higher prevalence in those with autoimmune connective tissue disease. This suggests that screening for thyroid disease in these populations may be beneficial 5. 

One study found that after successfully treating thyroid disease, thyroglobulin levels dropped back down into normal reference ranges 6. It is important to point out that this study tested the actual levels of thyroglobulin protein, not the TG-antibody levels. 

However, this finding is consistent with another study that found elevated anti-TG antibodies to correlate with the severity of hypothyroid symptoms, including fragile hair, swelling of the face and eyes, and vocal hoarseness 3.

Thyroglobulin autoantibodies may not be the best indicator of thyroid disease, but likely will continue to be useful in the screening and monitoring of select conditions. 

Thyroglobulin and Iodine Levels

Thyroglobulin is a protein secreted by the thyroid gland that aids in the production and storage of thyroid hormones. TG fluctuates with iodine levels, and high thyroglobulin levels may be an indicator of iodine deficiency or excess 7 8.

Iodine is a nutrient that is essential for the proper functioning of our thyroid gland. Iodine deficiency is an independent risk factor for underactive thyroid and can even lead to the development of a goiter (enlarged thyroid gland) and thyroid nodules 7.

Excess iodine blood levels can create toxicity symptoms, such as stomach pain, nausea and vomiting, and neurological dysfunction. Therefore, screening thyroglobulin levels may be useful in detecting abnormal iodine levels, as iodine is not routinely run on blood tests.

Other Thyroid Antibodies Like TPO May Be More Useful

Thyroid peroxidase antibody (TPO) levels are a much stronger indicator of an increased risk for thyroid disease. TPO antibodies are 90% sensitive in detecting thyroiditis, and are effective in monitoring the progression and severity of thyroid conditions 2.

Unlike thyroglobulin antibodies, TPO antibodies can stimulate the immune system and cause inflammation in thyroid tissue, leading to the development of thyroid disease 2. However, monitoring anti-TPO antibodies come with their own limitations.

The “normal” reference range for TPO antibodies is less than 35 IU/mL. But a 2016 study published in the Journal of Hormone and Metabolic Research 9 found:

• Those who had TPO antibodies below 500 IU/mL had a low risk of future progression to hypothyroidism. 
• Those who were above 500 IU/mL still only had a moderate risk. 

The Tehran Thyroid Study, which followed the course of thyroid disease in a large cohort of people over nine years, showed similar results: those with elevated TPO antibodies only had a 9-19% chance of becoming hypothyroid after 6 years of follow up 10 11.

If we consider this, elevated thyroid antibodies are not as consequential as many thyroid experts would suggest. 

I’ve commonly seen people with Hashimoto’s disease or elevated thyroid antibodies become hyper-focused on reducing their antibody test results to the “normal” reference range, and becoming unnecessarily stressed. The research suggests this isn’t necessary. 

Instead, it implies that only a minority of patients with elevated TPO antibodies will progress to full hypothyroidism. What this means for you is that you don’t have to continuously pursue lower and lower levels of antibodies with strict diets or supplements, especially if your thyroid symptoms are under control.

If you’re a patient, or a doctor working with patients, it’s important to understand that reducing TPO antibodies to under 500 IU/mL—or getting your thyroid symptoms under control through other means—is a clinical win.

Very High Thyroid Antibodies

All that said, if your TPO antibodies are very high, reducing your antibody count is definitely a worthwhile goal. The higher the TPO antibodies, the more likely you are to develop hypothyroidism.

The farther you reduce your TPO antibodies, even if you can’t get them down to 500 IU/mL, the less damage to your thyroid gland. Just don’t feel discouraged by failing to get them down to the “normal” reference range.

4 Ways to Reduce Thyroid Antibodies

There are several ways you can reduce your thyroid antibodies and improve your thyroid function, using diet and lifestyle.

1. Improve Your Gut Health

Preliminary evidence suggests that gut health is closely linked to thyroid health and that improving gut health can decrease thyroid antibodies and balance your thyroid hormones. Here are several ways you can work on improving your gut health.

• Anti-Inflammatory Diet: A low-quality diet is typically the single biggest source of inflammation that can impair your thyroid and immune function. But encouragingly, early evidence shows that changing your diet can lower thyroid antibodies.
  
  A low-carbohydrate diet was shown in one study to reduce thyroid antibodies by 44% in people with Hashimoto’s thyroiditis, but not celiac disease 12, while a gluten-free diet was shown to reduce thyroid antibodies in a group of women with Hashimoto’s thyroiditis 13. Other studies have shown that eliminating dairy or gluten may help improve thyroid function 14 15. A Paleo diet template is low carb, dairy-free, and gluten-free, and may be a good place to start.
  
  You may have heard of the Autoimmune Paleo diet, which has been shown in one small study to reduce thyroid symptoms and inflammatory markers 16. Many clinicians have seen their autoimmune patients respond well to the Autoimmune Paleo diet. However, the diet has yet to be shown to reduce thyroid antibodies. This doesn’t mean it’s not useful, but it may not be necessary to follow such a restricted diet to reduce thyroid antibodies.
• Gut Infections: Gut infections, such as H. pylori, SIBO (small intestinal bacterial overgrowth), and Blastocystis hominis are associated with elevated thyroid antibodies. Treating these infections may reduce thyroid antibodies 17 18 19 20 21.
• Probiotics: Probiotics have been shown in multiple studies to improve the gut infections that are associated with elevated thyroid antibodies, including H. pylori infection and SIBO (see above) 22 23. In another study, probiotics didn’t appear to improve thyroid antibodies, however, they did reduce the need for thyroid medication 24. More research is needed to confirm this effect, but probiotics appear to improve thyroid function.
• Digestive Support: Research shows that up to 40% of hypothyroid patients also have stomach autoimmunity, resulting in low stomach acid 25 26. Basic digestive supports such as digestive enzymes or stomach acid support may help thyroid function 27.

2. Supplements

• Selenium: Several studies, including a meta-analysis (the highest quality science) show selenium improves thyroid antibodies for hypothyroid patients 28 29 30. However, not all research agrees, and more studies need to be done.
• Vitamin D: Research suggests that vitamin D deficiency is associated with higher levels of thyroid antibodies 31, and that supplementation may decrease thyroid antibodies 32.
• CoQ10 & Magnesium: Some evidence suggests CoQ10 and Magnesium supplementation may reduce thyroid antibodies. CoQ10 has been shown to “improve thyroid vascularity,” and magnesium supports iodine uptake 33. One small study demonstrated supplementation with magnesium, CoQ10, and selenium along with additional supports reduced thyroid antibodies 34, while one additional study showed an association between low serum magnesium and thyroid antibodies 35.
• For more on supplements to support thyroid function, see How Should I Use Thyroid Supplements?

3. Light Therapy

There are some encouraging data showing that low-level laser therapy can improve thyroid function and decrease TPO antibodies. The therapy also reduced the amount of levothyroxine medication the patients needed, even after nine months of follow-up 36 37.

4. Optimize Iodine Levels

Iodine is an important nutrient for the thyroid gland, but must be used cautiously. Supplemental dietary iodine has been shown in several population-based studies to increase the incidence of autoimmune thyroid diseases 38 39. On the other hand, too little iodine can also cause thyroid symptoms. Optimizing your iodine levels may reduce thyroid antibodies.

For more on how to optimize your iodine, including how to test, see How Should I Use Thyroid Supplements?

Final Thoughts on Thyroid Antibodies

In summary, high thyroglobulin antibody levels likely hold little clinical relevance to the presence and severity of thyroid disease. TPO antibodies are a greater indicator of thyroid health and can be used to monitor the progression of thyroid dysfunction. 

However, even TPO antibodies come with their own limitations. Unless your TPO antibodies are very high, it’s not necessary to be hyper-focused on reducing your thyroid antibodies to the lab reference range. Reducing elevated TPO thyroid antibodies to below 500 IU/mL, and improving your thyroid function with diet and lifestyle changes significantly reduces your risk of developing hypothyroidism.

If you want help with reducing thyroglobulin antibody high levels or reducing thyroid symptoms, schedule an appointment at our center for functional health.

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