What Fish is Best for Hashimoto's Disease?

November 15, 2025 •

4 min read

Chronic inflammation is a key driver of Hashimoto's thyroiditis, and a growing body of research shows that diet can play a significant role in managing this condition. Incorporating specific types of fish into your diet is a strategic way to provide essential nutrients that support thyroid function and reduce inflammation, making you wonder what fish is best for Hashimoto's disease.

Quick Summary

This guide details the optimal fish choices for Hashimoto's disease, focusing on species rich in omega-3s and selenium while being low in mercury. It outlines key nutritional benefits, explains how to choose fish to minimize heavy metal exposure, and provides a comparison table of suitable options to help manage the autoimmune condition.

Key Points

Prioritize Oily, Low-Mercury Fish: Choose fish rich in omega-3s and selenium like salmon, sardines, and Atlantic mackerel to reduce inflammation and support thyroid function.
Avoid High-Mercury Species: Steer clear of large predatory fish such as swordfish, shark, and king mackerel, which can disrupt endocrine health.
Embrace Canned Options: Canned salmon and sardines offer an affordable, convenient, and nutrient-dense way to consume low-mercury fish regularly.
Use Anti-Inflammatory Cooking Methods: Bake, grill, or poach fish to preserve delicate omega-3 fatty acids, avoiding high-heat frying.
Consider Supplements if Needed: If regular fish intake is challenging, a high-quality fish oil supplement can ensure adequate omega-3 levels, after consulting a doctor.
Vary Your Intake for Balance: Rotating different types of low-mercury fish provides a wider range of micronutrients and prevents overexposure to any single element.

Understanding the Nutritional Needs for Hashimoto's

Hashimoto's thyroiditis is an autoimmune disorder where the immune system attacks the thyroid gland, leading to chronic inflammation and hypothyroidism. An anti-inflammatory diet is crucial for managing symptoms, and fish is a valuable component due to its nutrient profile. The key nutrients found in fish that are beneficial for Hashimoto's include:

Omega-3 Fatty Acids: These powerful anti-inflammatory agents can help reduce systemic inflammation associated with the autoimmune response. The specific long-chain omega-3s, EPA and DHA, are most prevalent in oily fish.
Selenium: This essential mineral is highly concentrated in the thyroid gland and plays a critical role in thyroid hormone metabolism. Selenium has been shown to reduce thyroid antibodies and inflammation in individuals with autoimmune thyroiditis.
Zinc: Adequate zinc levels are important for proper thyroid hormone formation and metabolism. Fish and shellfish are excellent sources of dietary zinc.
High-Quality Protein: Protein is vital for hormone production and overall cellular health. Fish provides a lean source of protein that supports immune function and muscle maintenance.

The Mercury Dilemma: Small Fish are Better

While fish offers many benefits, certain species contain high levels of mercury, a heavy metal that can disrupt endocrine function and potentially worsen autoimmune conditions. Larger, longer-lived predatory fish tend to bioaccumulate more mercury than smaller, shorter-lived fish. For this reason, selecting smaller fish is a key strategy for mitigating risk. Examples of high-mercury fish to limit or avoid include shark, swordfish, and king mackerel.

Top Fish Choices for Hashimoto's

Here is a list of the best fish for supporting thyroid health, balancing nutrient content with low mercury levels:

Wild-Caught Salmon: An excellent source of anti-inflammatory omega-3s (EPA and DHA), high-quality protein, and vitamin D. Wild salmon generally has a lower contaminant load than farmed alternatives.
Sardines: A powerhouse of nutrients, sardines offer high levels of omega-3s, selenium, vitamin D, and calcium (when eaten with the bones). They are a small, low-mercury fish, making them a safe and affordable choice.
Mackerel (Atlantic): Another oily, small fish, Atlantic mackerel is rich in omega-3 fatty acids and selenium. It is a sustainable, low-mercury option for regular consumption.
Trout: Both farmed and wild trout are good sources of omega-3s, vitamin B12, and vitamin D. Rainbow trout, especially farmed in freshwater ponds, is often a sustainable and low-mercury option.
Anchovies: Small and flavorful, anchovies are packed with omega-3s, selenium, and iron, with a very low mercury content. They are excellent for adding a savory depth to sauces and dishes.
Cod: As a white fish, cod is lower in omega-3s but is still a great source of lean protein, B vitamins, and iodine. It's a low-mercury choice and can be included as part of a varied diet.

Comparison of Fish Options for Hashimoto's


Fish Type	Key Nutrients	Omega-3 Content	Mercury Level	Recommended Frequency
Wild Salmon	Omega-3s, Selenium, Vitamin D, Protein	Very High	Very Low	1-2 times/week
Sardines (canned)	Omega-3s, Selenium, Calcium, Vitamin D	Very High	Very Low	1-2 times/week
Atlantic Mackerel	Omega-3s, Selenium, Vitamin B12	Very High	Very Low	1-2 times/week
Trout	Omega-3s, Vitamin B12, Vitamin D	High	Very Low	1-2 times/week
Anchovies	Omega-3s, Selenium, Iron	High	Very Low	Weekly, as a flavoring
Cod	Protein, Vitamin B12, Iodine	Low	Low	1-2 times/week
Swordfish	Omega-3s, Protein	High	Very High	Avoid
King Mackerel	Omega-3s, Protein	High	Very High	Avoid
Large Tuna (Bigeye)	Omega-3s, Protein	High	High	Limit/Avoid

Practical Tips for Incorporating Fish into Your Diet

Adopting a thyroid-friendly diet can feel overwhelming, but incorporating healthy fish is a simple and effective strategy. Here are some actionable tips:

Prioritize Wild-Caught: Whenever possible, choose wild-caught salmon over farmed to maximize omega-3 content and minimize potential contaminants.
Embrace Canned Fish: Canned sardines and salmon are convenient, cost-effective options that retain their nutritional value. Be sure to choose varieties packed in olive oil or spring water, and read labels to avoid excessive sodium.
Vary Your Fish Intake: Don't rely on just one type of fish. By rotating your selections from the low-mercury list, you ensure a broad spectrum of nutrients and prevent overexposure to any single contaminant.
Cooking Methods Matter: Lightly cooking fish through baking, grilling, or poaching is the best way to preserve its delicate omega-3 fatty acids. High-heat methods like frying can degrade these beneficial oils.
Consider a Supplement: If fish intake is limited, a high-quality fish oil supplement can be an excellent way to ensure adequate omega-3 intake. Always consult a healthcare provider before starting any new supplement.

Cooking Recommendations and Recipes

Integrating low-mercury fish into your weekly meals can be both healthy and delicious. For example, a simple weeknight dinner could feature baked salmon with roasted asparagus, which provides selenium and fiber. For a quick lunch, a salad with flaked canned sardines offers a potent dose of omega-3s, calcium, and protein. For something different, try making fish cakes with canned salmon instead of meat. Using herbs like dill and rosemary not only adds flavor but also offers additional anti-inflammatory benefits.

Conclusion: Making Informed Choices for Thyroid Health

In managing Hashimoto's disease, strategic dietary choices are a powerful tool alongside medical treatment. Selecting the best fish involves prioritizing low-mercury, oily fish rich in omega-3s and selenium, such as salmon, sardines, and mackerel. By making these intentional decisions, you can significantly support your thyroid health, manage inflammation, and improve your overall well-being. Always remember to discuss dietary changes with a healthcare provider or a registered dietitian to ensure they align with your specific needs. Incorporating a variety of these nutrient-dense fish will provide a strong foundation for your anti-inflammatory diet.

Frequently Asked Questions

Oily fish like salmon and sardines are rich in long-chain omega-3 fatty acids, specifically EPA and DHA. These fats have potent anti-inflammatory properties that help calm the autoimmune response and reduce inflammation associated with Hashimoto's.

Canned light tuna is lower in mercury than albacore or bigeye tuna and can be consumed in moderation. However, given its potential mercury content and the availability of equally nutritious, lower-mercury options like sardines, it is often recommended to prioritize smaller fish.

The NHS recommends eating at least two portions of fish per week, with one being an oily fish. For Hashimoto's, focus on consistently incorporating low-mercury, omega-3-rich fish 1-2 times per week to support anti-inflammatory goals.

Wild-caught fish, especially salmon, is generally preferred because it tends to have higher levels of omega-3s and fewer contaminants compared to some farmed varieties. However, some responsibly farmed fish can also be a healthy choice.

While iodine is necessary for thyroid hormone production, excessive intake can worsen Hashimoto's. The moderate amount of iodine in fish is typically not an issue. The risk of excessive iodine intake is higher with supplements or foods like seaweed.

For those who do not eat fish, plant-based sources of omega-3s include flaxseeds, chia seeds, and walnuts. However, the body's conversion of plant-based omega-3 (ALA) to the active forms (EPA and DHA) found in fish is inefficient. A high-quality fish oil or algae-based DHA/EPA supplement can be beneficial.

Yes. Healthier cooking methods like baking, steaming, or grilling preserve the delicate omega-3 fatty acids and other nutrients. Frying fish in unhealthy fats can degrade these benefits and add inflammatory compounds.