Does Cod Have a Lot of Metals? Understanding the Risks

November 14, 2025 •

4 min read

According to the U.S. Food and Drug Administration (FDA), cod is categorized as a “Best Choice” due to its low mercury content, making it one of the safest seafood options available for regular consumption. This assessment directly addresses the question of whether or not cod has a lot of metals, confirming its status as a healthy and low-risk option for most people.

Quick Summary

Cod is not high in mercury or other heavy metals, making it a safe choice for regular consumption. It is low on the food chain, which means it accumulates fewer contaminants compared to larger predatory fish like swordfish or shark. Atlantic and Pacific cod differ slightly in mercury levels, though both are safe in moderation.

Key Points

Cod is low in mercury: Federal health agencies, including the FDA, classify cod as a 'Best Choice' for consumption due to its low mercury content, making it a safe option for most individuals.
Mercury levels depend on species and source: While both Atlantic and Pacific cod are low in mercury, wild-caught Atlantic cod is often cited as being lower than Pacific cod. Sustainable sourcing is recommended to ensure the highest quality.
Low on the food chain: Cod's position lower on the aquatic food chain means it accumulates significantly less mercury through biomagnification compared to larger, predatory fish like swordfish, shark, and certain tuna varieties.
Minimal other heavy metal concerns: Scientific testing has shown that levels of other heavy metals, such as cadmium and arsenic, are also well below maximum safety limits in cod fillets.
High nutritional value: Beyond low metal content, cod is a healthy choice rich in lean protein, omega-3 fatty acids, and essential minerals like selenium and phosphorus, offering significant health benefits.
Safe for most populations: Moderate consumption of cod is safe for most people, including pregnant women and young children, who are advised to choose low-mercury fish.

Understanding Heavy Metals in Fish

Concerns about heavy metals, particularly mercury, in fish are common and legitimate. Mercury, a neurotoxin, enters aquatic ecosystems primarily through industrial and natural sources. In the water, microorganisms convert inorganic mercury into methylmercury, a highly toxic organic form that is then absorbed by small marine life. The concentration of methylmercury increases as it moves up the food chain, a process known as biomagnification. This is why large, predatory fish tend to have the highest levels of mercury. Cod, being lower on the food chain, is therefore less susceptible to this process compared to species like shark or swordfish.

Cod's Position on the Mercury Spectrum

Regulatory bodies like the FDA and EPA regularly monitor and publish guidance on mercury levels in different fish species to help consumers make informed decisions. Cod consistently ranks among the lower-mercury choices, often alongside other small fish and shellfish. The mercury content can vary slightly depending on the species and source, but the overall risk remains low.

Comparing Atlantic vs. Pacific Cod

There are two main species of cod commonly found in the market: Atlantic and Pacific. While both are considered low in mercury, there can be slight variations.

Atlantic Cod: Often cited as a very low-mercury option. One study cited in a Reddit discussion mentioned wild Atlantic cod having a mercury level of 0.070 ppm, which is significantly lower than average tuna. This is one of the safest varieties.
Pacific Cod: Found to have slightly higher mercury levels than Atlantic cod, though still well within safe limits for moderate consumption. Some conservative recommendations suggest limiting consumption for vulnerable groups like young children and pregnant individuals, though other bodies consider it a 'Best Choice'. Opting for wild-caught versions is often recommended over farmed alternatives, which can sometimes be exposed to more contaminants.

Not Just Mercury: Other Metals in Cod

While mercury is the most talked-about heavy metal, other metals such as cadmium, arsenic, and lead can also accumulate in fish. Scientific studies and monitoring programs, such as those conducted by NIFES in Norway, have shown that heavy metal levels in cod are well below established safety limits. These analyses, which include cadmium and arsenic, have consistently found that concentrations are not a problem for food safety. In general, the liver and other organs of fish tend to accumulate higher concentrations of metals than the muscle tissue, which is the primary part consumed by humans.

The Health Benefits of Eating Cod

Despite the minimal risk of heavy metal contamination, cod offers a wealth of nutritional benefits that contribute to its status as a healthy food. It is a lean source of protein and rich in essential vitamins and minerals.

Rich in Selenium: Cod is an excellent source of selenium, a mineral vital for thyroid function, DNA production, and a healthy immune system.
Good Source of B Vitamins: Cod contains several B vitamins, including B12 and niacin, which are crucial for energy production, nerve function, and red blood cell formation.
Source of Omega-3s: While not as high in omega-3s as fatty fish like salmon, cod does contain healthy omega-3 fatty acids that support heart and brain health. Cod liver oil is an especially concentrated source of omega-3s and vitamins A and D.

Cod vs. Other Fish: A Comparison Table


Fish Type	Typical Mercury Level (ppm)	Mercury Category (FDA/EPA)	Omega-3 Content	Notes
Cod	~0.111	Best Choice (Low)	Moderate (Lower than salmon)	Versatile, mild flavor, excellent lean protein.
Salmon	~0.022	Best Choice (Lowest)	High (especially wild-caught)	Fatty fish with many health benefits, very low mercury.
Canned Light Tuna	~0.128	Best Choice (Low)	Varies by species, but moderate	Skipjack tuna is often used; a safe and popular option.
Canned Albacore Tuna	Higher than canned light	Good Choice	High	Higher mercury than canned light tuna, should be consumed less frequently.
Swordfish	~0.995	Choices to Avoid (Highest)	Moderate to High	Large predator, accumulates high mercury levels.
Shark	~0.979	Choices to Avoid (Highest)	High	Top predator, very high mercury content.

How to Safely Enjoy Cod

To ensure the safest and most beneficial consumption of cod, follow these tips:

Choose Sustainable Sources: Opt for cod caught using sustainable practices. For example, Alaskan Pacific cod fisheries are often praised for their responsible management. For Atlantic cod, check for certifications from organizations like the Marine Stewardship Council (MSC). Overfishing has been a concern for some cod populations, so sustainable sourcing is important.
Vary Your Seafood Intake: While cod is low in mercury, a varied diet is always the best approach. Incorporate other low-mercury options like salmon, sardines, and shrimp to maximize your nutritional intake.
Properly Cook the Fish: Always cook cod thoroughly to an internal temperature of 145°F to kill any potential bacteria or parasites. However, avoid overcooking, as cod is a lean fish that can become tough if cooked for too long.
Mind Your Consumption: For most healthy adults, consuming cod multiple times a week is perfectly safe. However, sensitive populations like pregnant women and young children should follow specific guidelines for seafood consumption recommended by health authorities.

Conclusion

In summary, the claim that cod has a lot of metals is largely unfounded. Numerous scientific studies and regulatory assessments confirm that cod, particularly species like wild Atlantic and Pacific cod, has low levels of mercury and other heavy metals. Its low trophic level prevents the high accumulation seen in larger predatory fish. Cod remains a nutritious and safe seafood choice, rich in lean protein, essential vitamins, and beneficial minerals. By choosing sustainable sources and maintaining a varied seafood diet, consumers can confidently enjoy the health benefits of cod with minimal concern over heavy metal exposure.

Authoritative Outbound Link

For the latest comprehensive guidance on fish consumption and mercury levels, consult the advice from the U.S. Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) at the following link: Advice about Eating Fish.

Frequently Asked Questions

No, cod is not a high-mercury fish. It is categorized by the FDA as a 'Best Choice,' meaning it has one of the lowest mercury concentrations among popular seafood options.

Both Atlantic and Pacific cod are generally safe, low-mercury choices. However, some data suggest that wild Atlantic cod may contain slightly less mercury than Pacific cod, though both fall well within safe consumption limits.

High-quality cod liver oil products are carefully purified to remove heavy metals and other contaminants. Reputable brands test their products to ensure that levels of mercury, lead, and cadmium are well below acceptable standards.

For most healthy adults, consuming cod regularly, even a few times a week, is safe. The FDA recommends a varied diet and provides guidance for vulnerable groups, such as pregnant women, who should stick to 8-12 ounces of low-mercury fish per week.

Cod has significantly lower mercury levels than tuna, especially large predatory tunas like bigeye or albacore. Cod typically falls into the 'Best Choice' (lowest mercury) category, while some types of tuna are considered a 'Good Choice' with moderate levels.

The main reason cod is low in heavy metals is its position lower on the food chain. As a less predatory fish, it consumes smaller organisms that have not accumulated high concentrations of contaminants through biomagnification.

No, cooking fish does not remove mercury. Mercury is bound to the fish's muscle tissue, so it remains present whether the fish is raw, baked, or fried.