Does Store-Bought Tuna Have Mercury in It?

November 27, 2025 •

3 min read

According to the World Health Organization, mercury is one of the top ten chemicals of major public health concern. All store-bought tuna contains mercury, but the levels vary significantly depending on the species. Understanding the different types of tuna and their mercury concentrations is key to making informed and safer dietary choices.

Quick Summary

All store-bought tuna contains mercury, though levels differ by species, with larger fish like albacore having more than smaller skipjack. Limiting consumption and choosing lower-mercury options can help mitigate health risks, which are especially concerning for pregnant women and young children.

Key Points

Mercury is present in all tuna: All tuna, including canned and fresh, contains some level of mercury, which accumulates in the fish's tissues over its lifespan.
Mercury levels vary by species: Larger, older tuna species like albacore and bigeye have significantly higher mercury concentrations than smaller, younger species like skipjack.
Choose light tuna for lower mercury: Canned light tuna, which is typically skipjack, is the lowest mercury option and is considered a "Best Choice" by the FDA.
Albacore should be limited: Canned albacore, also known as white tuna, has higher mercury levels and should be consumed in more limited quantities, particularly by pregnant women and children.
Vulnerable groups need special caution: Pregnant women, breastfeeding mothers, and young children are most susceptible to the effects of mercury and should be particularly mindful of their tuna consumption.
Balance risk with nutritional benefits: Despite mercury concerns, tuna provides beneficial nutrients like protein and omega-3s. The key is moderation and choosing lower-mercury varieties to balance the intake of nutrients and potential risks.
Look for sustainable sources: Some brands test every fish for mercury, and sustainable practices like pole-and-line fishing often target smaller, lower-mercury fish.

Why Is There Mercury in Tuna?

Mercury is a naturally occurring element, but industrial pollution from sources like coal-burning power plants significantly increases its presence in the environment. In the ocean, bacteria convert this mercury into a highly toxic organic form called methylmercury. This methylmercury then enters the marine food chain. Small organisms absorb it and are consumed by larger fish. This process, known as bioaccumulation, means that mercury concentrations increase as they move up the food chain. Tuna, being a predatory fish, accumulates significant levels of methylmercury throughout its life, with larger, older tuna species containing the highest concentrations.

Different Types of Tuna and Their Mercury Levels

The amount of mercury in a can of tuna depends on the species of fish used. Canned tuna is generally safer than fresh, as it is often made from smaller, younger fish. However, canned albacore and canned light tuna use different species, resulting in distinct mercury levels.

Canned Light Tuna vs. Canned Albacore

Canned Light Tuna: Typically made from smaller, younger species like skipjack, it has much lower mercury levels than albacore. This is often considered a "Best Choice" by the FDA and EPA for frequent consumption.
Canned Albacore Tuna: Known as "white" tuna, it comes from larger, longer-living albacore tuna. Consequently, it accumulates more mercury than light tuna and is classified as a "Good Choice" with more limited consumption recommendations.
Bigeye and Yellowfin Tuna: These species, often used for sushi or sold as fresh or frozen steaks, have higher mercury levels than canned varieties and should be eaten sparingly, especially by sensitive populations.

A Comparison of Mercury Levels in Tuna Varieties

This table outlines the average mercury content in different commercial tuna products based on FDA and Healthline data.


Tuna Species (Product)	Average Mercury Concentration (ppm)	FDA/EPA Classification	Recommended Weekly Servings (per 4 oz)
Canned Light Tuna (Skipjack)	0.126	Best Choice	2–3 servings
Canned White Tuna (Albacore)	0.350	Good Choice	1 serving
Fresh/Frozen Yellowfin	0.354	Good Choice	1 serving
Fresh/Frozen Bigeye	0.689	Choices to Avoid	Avoid entirely

Who Should Be Most Cautious About Mercury in Tuna?

While most healthy adults can safely consume tuna in moderation, certain populations are more vulnerable to the neurotoxic effects of methylmercury.

Pregnant and Breastfeeding Women: The developing fetal brain and nervous system are extremely vulnerable to mercury. While omega-3 fatty acids in fish are beneficial for development, experts recommend sticking to low-mercury options like canned light tuna in limited quantities, or avoiding tuna altogether based on some research showing unpredictable mercury spikes.
Young Children: Children have lower body weights, making them more susceptible to mercury accumulation. They should only consume canned light tuna and adhere to age-appropriate serving sizes.
Individuals Who Eat Fish Frequently: Those who eat fish more than a few times a week should be especially mindful of their choices to avoid exceeding safe mercury intake levels.

How to Reduce Your Mercury Exposure from Tuna

Limiting your mercury intake doesn't mean you have to give up tuna entirely. Following these steps can help you enjoy the nutritional benefits of seafood while minimizing risk.

Choose the Right Type: Opt for canned light (skipjack) tuna over albacore for lower mercury levels.
Vary Your Seafood: Diversify your diet with other low-mercury fish such as salmon, sardines, and shrimp to ensure you still receive vital omega-3s without excessive mercury.
Check Labels: Some brands voluntarily test their tuna for mercury, offering an additional layer of assurance.
Consider Sustainable Practices: Brands that use methods like pole-and-line fishing often target younger, smaller fish, which typically have lower mercury content.

Conclusion: Navigating Tuna Consumption with Awareness

Yes, store-bought tuna does have mercury, but the levels are not uniform across all products. The key takeaway is to be a conscientious consumer. By selecting smaller, lower-mercury species like skipjack (found in canned light tuna) and moderating your intake, you can continue to enjoy the nutritional benefits of tuna while keeping mercury exposure in check. The overall net effect of consuming seafood has been shown to be beneficial for health, but making smart choices remains paramount for vulnerable groups, including pregnant women and young children. Healthline offers additional tips on making safer seafood choices.

Note: This article provides general nutritional advice. Always consult with a healthcare professional regarding specific dietary concerns, especially for vulnerable populations.

Frequently Asked Questions

No, not all canned tuna has the same level of mercury. The mercury content depends on the species of tuna used. Canned light tuna, typically made from smaller skipjack, has much lower levels than canned albacore or 'white' tuna.

The type of store-bought tuna with the lowest mercury content is canned light tuna, which is most often made from the skipjack species.

Yes, excessive consumption of high-mercury tuna can lead to mercury poisoning over time, as the heavy metal accumulates in the body. It is important to follow recommended serving guidelines based on the type of tuna.

Yes, in moderation, but it is advised to stick to canned light tuna, which is lower in mercury. The FDA recommends pregnant women consume 2 to 3 servings (8-12 ounces) of low-mercury fish per week and avoid high-mercury species.

Draining canned tuna, whether packed in water or oil, does not significantly reduce its mercury content. Methylmercury is bound to the fish's tissue, not the liquid in the can.

Tuna is not typically farm-raised, and mercury levels are more dependent on the species, age, and location rather than the farming method. Larger, older wild tuna will have more mercury than smaller ones.

Yes, many other fish have very low mercury levels and are excellent sources of nutrients. Some of these include salmon, sardines, shrimp, and tilapia.

Tuna is a good source of protein, healthy omega-3 fatty acids, and essential vitamins and minerals. When consumed in moderation and by choosing lower-mercury varieties, the nutritional benefits can outweigh the risks for most people.