What seafood is good for your thyroid? A guide to essential nutrients

November 8, 2025 •

5 min read

The thyroid gland contains a higher concentration of selenium per gram than any other organ in the body, emphasizing its role in supporting proper thyroid function. Choosing the right seafood can be a powerful way to provide key nutrients like iodine, selenium, and omega-3s, and understanding what seafood is good for your thyroid is a critical part of dietary management.

Quick Summary

This article outlines which types of seafood provide key nutrients such as iodine, selenium, and omega-3s, which are vital for healthy thyroid function. It covers recommended options, potential risks like mercury, and offers practical advice for making informed dietary choices to support your thyroid.

Key Points

Rich in Selenium: Fatty fish like tuna, salmon, and sardines are excellent sources of selenium, which protects the thyroid from oxidative damage.
Source of Iodine: Cod, shrimp, and seaweed are potent sources of iodine, essential for producing thyroid hormones, but extremely high-iodine foods should be consumed in moderation.
Anti-Inflammatory Omega-3s: Oily fish such as salmon, mackerel, and sardines contain omega-3s, which help reduce inflammation linked to autoimmune thyroid diseases like Hashimoto's.
Boosts Zinc Intake: Shellfish, including oysters and crab, provide crucial zinc, a mineral necessary for thyroid hormone production and regulation.
Mindful of Mercury: Limit high-mercury fish like swordfish and shark, as mercury can negatively impact thyroid function and potentially trigger autoimmune issues.
Prioritize Low-Mercury Seafood: Focus on lower-mercury options like wild salmon, cod, and sardines to gain health benefits with minimal risk.

The Role of Key Nutrients in Thyroid Function

The thyroid, a butterfly-shaped gland located at the base of your neck, is responsible for producing hormones that regulate metabolism, heart rate, energy levels, and more. A healthy thyroid depends on several key nutrients, many of which can be found in seafood. By incorporating specific types of seafood into your diet, you can provide your body with the building blocks it needs to function optimally.

Iodine: Essential for Hormone Production

Iodine is a fundamental nutrient required for the synthesis of thyroid hormones T4 and T3. The body cannot produce iodine on its own, so it must be obtained through diet. While iodized salt is a common source, seafood offers a natural and potent supply. Adequate, but not excessive, intake is key, particularly for those with existing thyroid conditions.

Excellent seafood sources of iodine include:

Cod: A 3-ounce serving of baked cod can provide a significant portion of the recommended daily intake.
Shrimp: This popular shellfish is a good source of iodine and is also low in calories.
Seaweed: Nori, kelp, and wakame are extremely rich in iodine. However, due to the high concentration, intake should be carefully managed to avoid overconsumption, which can be detrimental to the thyroid.
Mussels: These mollusks are another top source of iodine.

Selenium: The Thyroid's Antioxidant Protector

Selenium is a trace mineral that acts as a powerful antioxidant within the thyroid gland, protecting it from oxidative stress during hormone production. It is also critical for converting the inactive thyroid hormone T4 into its active form, T3.

Seafood rich in selenium includes:

Tuna: Both canned light and yellowfin tuna are excellent sources of selenium.
Sardines: These small, oily fish are packed with selenium and omega-3 fatty acids.
Oysters: Oysters offer a healthy dose of selenium, along with immune-boosting zinc.
Salmon: A great source of both selenium and anti-inflammatory omega-3s.

Omega-3 Fatty Acids: Combating Inflammation

For individuals with autoimmune thyroid conditions like Hashimoto's or Graves' disease, inflammation can worsen symptoms. Omega-3 fatty acids, particularly EPA and DHA found in fatty fish, have potent anti-inflammatory properties that can help mitigate this effect.

Fatty fish high in omega-3s include:

Salmon: Wild-caught salmon is particularly known for its high omega-3 content.
Mackerel: A very rich source of omega-3s, often available smoked or canned.
Sardines: In addition to selenium, sardines are a powerhouse of omega-3s.
Herring: Another small, oily fish that is a fantastic source of omega-3s.

Zinc: A Regulator of Hormone Levels

Zinc is another mineral essential for thyroid hormone production and function. Both hypothyroidism and hyperthyroidism can be associated with zinc deficiency.

Seafood sources of zinc include:

Oysters: These are one of the richest dietary sources of zinc.
Alaskan King Crab and Lobster: These shellfish also contain significant amounts of zinc.

Potential Risks: Mercury and Autoimmune Conditions

While seafood provides important nutrients, it's crucial to be aware of potential risks, especially concerning mercury and its impact on the thyroid. Larger, predatory fish tend to accumulate higher levels of mercury. For individuals with autoimmune thyroid diseases like Hashimoto's, excessive iodine can sometimes exacerbate the condition. Balance is key.

Comparison of Seafood for Thyroid Health


Seafood Type	Key Nutrients for Thyroid	Potential Drawbacks	Recommendations for Thyroid Diet
Wild Salmon	Omega-3s, Selenium, Vitamin D	Lower iodine than white fish	Excellent choice for anti-inflammatory benefits; prioritize wild-caught
Cod	Iodine, Protein, Selenium	Lower omega-3s than fatty fish	Great for a steady source of iodine; versatile and low in fat
Sardines	Omega-3s, Selenium, Iodine, Vitamin D	Canned options can be high in salt	A nutrient-dense, affordable choice; excellent for overall thyroid support
Oysters	Zinc, Selenium, Iodine	High in zinc and potentially inflammatory	Excellent source of zinc, but be mindful of total iodine intake
Tuna (Canned Light)	Selenium, Iodine, Omega-3s	Contains some mercury; canned options can be high in salt	A decent source of selenium and iodine, but choose light tuna to minimize mercury
Seaweed (Kelp, Nori)	Very High Iodine	Risk of excessive iodine intake	Use sparingly or in moderation, especially if you have a thyroid condition
Swordfish/Shark	Omega-3s	Very high mercury levels	Avoid due to high mercury content, which can trigger autoimmune responses

Making Smart Choices

To maximize the benefits of seafood for your thyroid, focus on variety and moderation. A balanced intake of both iodine- and selenium-rich options is essential. For those with autoimmune thyroid conditions, limiting extremely high iodine sources like kelp and focusing on the anti-inflammatory properties of omega-3s is a prudent strategy. Always choose low-mercury options to avoid potential toxin exposure.

Conclusion

Supporting your thyroid through diet is a valuable strategy, and seafood provides a rich source of key nutrients like iodine, selenium, omega-3s, and zinc. By making informed choices, prioritizing lower-mercury options like wild salmon, sardines, and shrimp, and moderating your intake of high-iodine seaweed, you can help maintain optimal thyroid function. Always consult with a healthcare provider or a registered dietitian to create a personalized nutritional plan, especially if you have a pre-existing thyroid condition. The National Institutes of Health provides comprehensive fact sheets on essential nutrients for health, which can be a useful resource.

Incorporating Seafood into Your Thyroid-Healthy Diet

To ensure you reap the full benefits, focus on a varied diet rather than overemphasizing a single food. Here are some ways to prepare thyroid-friendly seafood meals:

Baked Salmon: Season a wild-caught salmon fillet with lemon, garlic, and dill, then bake until flaky. Serve with roasted vegetables.
Shrimp Stir-Fry: Sauté shrimp with a variety of colorful vegetables like bell peppers and spinach in a light sauce. Use a base of brown rice for additional nutrients.
Sardine Toasts: Top whole-grain toast with mashed avocado and canned sardines for a quick, nutrient-packed meal or snack.
Cod Fish Tacos: Use baked cod fillets in tacos with fresh cabbage slaw and a squeeze of lime.
Seafood Salad: Mix cooked shrimp and crab with chopped celery, onion, and a yogurt-based dressing for a light, refreshing meal.

Remember to balance your meals with a variety of other nutrient-dense foods to support overall health.

Disclaimer: The information in this article is for informational purposes only and does not constitute medical advice. Consult a healthcare professional before making significant changes to your diet, especially if you have a thyroid condition.

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Frequently Asked Questions

For hypothyroidism, prioritize seafood rich in selenium and omega-3s, such as wild salmon, sardines, and canned light tuna. These nutrients support hormone conversion and reduce inflammation, which is often a factor in autoimmune hypothyroidism.

Adequate iodine is essential for thyroid hormone production. Seafood is a rich natural source. However, excessive iodine can harm the thyroid, especially for those with autoimmune conditions like Hashimoto's. A balanced intake from sources like cod and shrimp is generally beneficial, but very high sources like kelp should be limited.

Larger, predatory fish tend to have higher mercury levels. Avoid or limit swordfish, shark, king mackerel, bigeye tuna, and tilefish. Choose lower-mercury options like wild salmon, sardines, cod, and shrimp instead.

Selenium is crucial for converting inactive T4 hormone into the active T3 form and acts as an antioxidant to protect the thyroid gland from oxidative damage that occurs during hormone synthesis. Seafood like yellowfin tuna, sardines, and oysters are excellent sources.

Yes, particularly fatty fish rich in omega-3 fatty acids, like wild salmon and sardines. These omega-3s help reduce the inflammation often associated with autoimmune thyroid diseases. However, be cautious with extremely high-iodine seafood like kelp.

Yes, many canned options are excellent. Canned light tuna and sardines are good sources of selenium and omega-3s. Canned salmon also retains high levels of omega-3s. Always check labels for added salt and choose lower-mercury types like light tuna.

Aim for a moderate intake of 2-3 servings of a variety of seafood per week, focusing on low-mercury fish and shellfish. This provides a balanced supply of essential nutrients like iodine, selenium, and omega-3s without the risk of overconsumption.