For some individuals, worrying about elevated thyroid antibodies may be an unfounded concern. Indeed, elevated thyroid antibodies are one of the markers of autoimmune thyroid diseases like Hashimoto’s thyroiditis. However, research shows that moderately elevated thyroid antibodies do not necessarily bring about thyroid disorders.
In this article, we will explain what thyroid antibodies are and their roles in the human body. We will also share the optimal reference range for thyroid antibodies and what to do if your antibodies are high.
5 Key Thyroid Enzymes and Hormones
Before we discuss thyroid antibodies, let’s look at the specific roles of thyroid hormones and enzymes in the human body:
- TSH (thyroid-stimulating hormone or thyrotropin): TSH regulates thyroid function by controlling the amount of T4 and T3 hormones produced in the thyroid gland .
- T4 (thyroxine): T4 is a thyroid hormone produced in the thyroid gland. It is converted to the active T3 when it enters the bloodstream .
- T3 (triiodothyronine): T3 is the thyroid hormone most actively involved in regulating body functions. It is both produced in the thyroid gland and converted from T4 in the bloodstream. .
- TPO (thyroid peroxidase or thyroperoxidase): TPO is the main enzyme involved in producing T4 and T3 .
- TG (thyroglobulin): TG is a protein involved in producing T4 and T3 .
What Are Thyroid Antibodies?
Antibodies play an important role in your immune function. Their job is to seek out and destroy foreign invaders in the body — viruses, bacteria, fungi, and parasites.
Thyroid antibodies — also called antithyroid antibodies and thyroid autoantibodies — are a sign of an autoimmune response in your body. Instead of attacking foreign invaders, thyroid antibodies attack the thyroid enzymes and proteins (TPO and TG) that are needed for normal thyroid function.
Chronic high levels of thyroid antibodies can result in thyroid dysfunction, including:
- Thyroiditis (inflammation of the thyroid gland)
- Hypothyroidism (excessively low thyroid hormone levels)
- Hyperthyroidism (excessively high thyroid hormone levels)
Thyroid-related autoimmune disorders involve a combination of elevated thyroid antibodies and one or more of the dysfunctions described above:
- Hashimoto’s thyroiditis is diagnosed when you have elevated thyroid antibodies combined with hypothyroidism (underactive thyroid gland). It is the most common autoimmune thyroid disease.
- Graves’ disease is diagnosed when you have elevated thyroid antibodies combined with hyperthyroidism (overactive thyroid gland).
Two types of thyroid antibodies act in distinctive ways to damage the thyroid gland:
- Thyroid peroxidase antibodies (anti-TPO): Anti-TPO antibodies inhibit the enzyme thyroid peroxidase, which decreases thyroid hormone production. Chronic elevated anti-TPO can trigger hypothyroidism and lead to thyroid cell destruction.
- Thyroglobulin antibodies (anti-TG): Anti-thyroglobulin antibodies inhibit the enzyme thyroglobulin. Unlike anti-TPO antibodies, anti-TG does not appear to cause cell destruction.
Anti-TPO is the most reliable lab marker for autoimmune thyroid disease while anti-TG is less reliable as a disease marker.
What a Thyroid Panel Can Tell You About Thyroid Autoimmunity
Thyroid antibody tests are useful diagnostic tools for identifying autoimmune thyroid disease.
Doctors typically test for T4 and TSH levels to diagnose hypothyroidism, and this is a completely reliable method. However, a full thyroid panel, which includes blood tests for thyroid antibodies, can tell you if hypothyroidism is the result of an autoimmune condition.
The “normal” reference range for TPO antibodies is less than 35 IU/mL. If you are hypothyroid and have TPO antibodies above the reference range, you will likely be diagnosed with Hashimoto’s disease.
Should You Worry About Your Thyroid Antibody Levels?
Functional medicine approaches can help autoimmune thyroid patients to lower antibody levels. Lowering antibodies through dietary and lifestyle interventions is a smart choice for most thyroid patients, but sometimes a good idea can get carried too far.
It’s not unusual for patients to become hyper-focused on getting their antibody levels down to zero. This type of zealousness can be counterproductive as it leads to unnecessary stress. The notion that thyroid antibodies should be completely eradicated is not backed up by science.
Research suggests that moderately elevated TPO antibodies are not associated with thyroid damage. A 2016 study in the Journal of Hormone and Metabolic Research  discovered:
- Individuals with TPO antibodies below 500 IU/mL had a low likelihood of future hypothyroidism.
- Individuals with TPO antibodies above 500 IU/mL are only moderately at risk for hypothyroidism.
In addition, the Tehran Thyroid Study tracked the thyroid disease progress of a large cohort of participants over nine years. After six years of follow-up, the study found that only 9-19% of individuals with elevated TPO antibodies became hypothyroid [7, 8].
The bottom line is, elevated thyroid antibodies are not as consequential as the recommended reference range suggests. Not everyone with elevated thyroid antibodies will become hypothyroid.
A Rational Approach to Thyroid Antibodies Levels
If your thyroid symptoms are under control and your anti-TPO antibodies are below 500 IU/mL, there’s little need to try to lower antibody levels further with strict diets or supplements. Celebrate your good health and enjoy life!
If your anti-TPO levels are above 500, you should take steps to lower them.
9 Functional Remedies To Reduce Thyroid Antibodies
If your test results show that anti-TPO antibodies exceed 500 IU/mL, the following approaches can help decrease antibody levels, improve thyroid function, reduce thyroid symptoms, and prevent further thyroid damage.
Boost Gut Health
1. Anti-Inflammatory Diets
A diet high in inflammatory foods undermines your immune system and thyroid function. Switch to an anti-inflammatory diet to lower your thyroid antibodies.
The Paleo diet is a good starting place to address thyroid health concerns, as it focuses on fresh, whole foods and reduces inflammatory, processed foods. It also removes dairy and gluten, which are common food sensitivities. Two studies have noted that gluten- or dairy-free diets may improve thyroid function [10, 11].
Many thyroid patients benefit from lowering carbs in their diet. One study showed that a low-carbohydrate diet significantly reduced thyroid antibodies by 44% in autoimmune thyroiditis patients . The Paleo diet is lower in carbs and can help to achieve this.
Many practitioners recommend the Autoimmune Paleo diet (AIP) for those with autoimmune thyroid conditions. While research is limited, one small study showed that thyroid patients successfully managed thyroid symptoms and inflammation with the AIP diet .
The AIP diet is a more restrictive version of the Paleo diet and removes some of the less common trigger foods. We generally recommend that patients start with a basic Paleo diet and progress to the AIP diet if thyroid symptoms haven’t fully resolved after 30 days of following the Paleo diet.
Probiotics rebalance the gut microbiota, diminish gut inflammation, and help to heal the gut lining. Better gut health leads to a calmer immune system and may help to reduce thyroid autoimmunity.
While there is little direct research into the effects of probiotics on thyroid antibody levels, multiple studies show that an association between gut infections and thyroid autoimmunity. Probiotics improve gut infections that are associated with elevated thyroid antibodies, including H. pylori infection and SIBO [14, 15]. One study found that probiotics can reduce the need for thyroid medication and reduce fatigue in hypothyroid patients .
3. Digestive Support
Digestive issues, like food sensitivities and low stomach acid, are associated with thyroid disorders.
Up to 40% of hypothyroid individuals suffer from stomach autoimmunity [17, 18], which can lead to low levels of stomach acid. For these patients, stomach acid support in the form of HCI with betaine supplements may help boost their thyroid function .
For some patients with food sensitivities, digestive enzyme supplements can help to reduce immune responses to trigger foods, such as the lactose in dairy products.
4. Gut Infection Treatments
When patients are not able to fully reduce thyroid antibodies and resolve thyroid symptoms with diet and supplements alone, we typically suspect an underlying gut infection.
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 [20, 21, 22, 23, 24].
One small but remarkable study found that when thyroid patients were treated for H. pylori infection, patients had an average drop in TPO antibodies of 2029 .
Our clinical team can help to diagnose and treat hidden gut infections that may be contributing to poor thyroid health.
Try Dietary Supplements
Poor gut health may lead to nutritional deficiencies. Dietary supplements can help correct micronutrient deficiencies that impact thyroid function.
Dietary supplements should be taken as a complement to gut-directed therapies, not as a stand-alone treatment.
Selenium is essential for the conversion of T4 to T3 . Its deficiency is associated with thyroid dysfunction and thyroid disorders [27, 28]. While more research is needed, several studies (including a meta-analysis) noted lower thyroid antibody count in autoimmune thyroiditis patients after selenium supplementation [29, 30, 31].
6. Vitamin D
Vitamin D deficiency is associated with hypothyroidism, Hashimoto’s thyroiditis, and Graves’ disease [32, 33, 34]. Correcting this insufficiency with vitamin D supplements is a potential remedy for lowering TPO and TG antibodies [35, 36, 37].
7. Coenzyme Q10 and Magnesium
As essential micronutrients, coenzyme Q10 (CoQ10) and magnesium may decrease thyroid antibody levels. In fact, low serum magnesium was linked to an increased risk of elevated thyroid antibodies in one study . A preliminary study also suggested that CoQ10, magnesium, and selenium reduce thyroid antibodies .
8. Consider Light Therapy
9. Optimize Iodine Levels
Iodine is a vital nutrient in the production of thyroid hormones. Iodine deficiency is associated with goiter and hyperthyroidism . Unfortunately, iodine supplementation is a double-edged sword and can increase the prevalence of autoimmune thyroid disease in some individuals [43, 44]. It’s best to consult your functional medicine doctor to decide if iodine may be helpful for your symptoms.
Austin FM Helps You Get Your Thyroid Antibodies in Check
While TPO antibody levels above 35 IU/mL are considered elevated, research shows that levels below 500 IU/mL have a significantly lower risk for thyroid disease.
Simple yet effective lifestyle changes that can lower thyroid antibodies include anti-inflammatory food choices and probiotic supplements to balance the gut ecology. Hidden gut infections may be the root cause of elevated thyroid antibodies for a subset of thyroid patients.
Aim to get your anti-TPO levels below 500. Trying to lower thyroid antibodies to near-zero levels can do more harm than good, and is not recommended.
An experienced functional medicine doctor can help get your thyroid antibodies in check. At Austin Functional Medicine, Dr. Michael Ruscio and his team are available through in-house and telemedical appointments to provide you the relief you need.