Which Canned Fish is High in Mercury?

According to the U.S. Food and Drug Administration (FDA), nearly all fish contain trace amounts of mercury, but levels vary significantly depending on the species. The risk of mercury exposure, especially for sensitive groups, depends on the type and amount of fish consumed. This guide will detail which canned fish is high in mercury and provide safer alternatives for your diet.

Quick Summary

This guide explains which types of canned fish have high mercury levels and highlights safer alternatives. Learn how fish size and diet affect mercury accumulation, and understand consumption recommendations for different populations.

Key Points

• Albacore tuna is highest in mercury: Canned albacore, or 'white tuna,' contains significantly higher mercury levels compared to other common canned fish.

• Larger predatory fish accumulate more mercury: Species at the top of the food chain, like king mackerel and bigeye tuna, accumulate the most methylmercury over their lifetime.

• Canned light tuna is a safer choice: Opt for canned light tuna, typically from the smaller skipjack species, as it has much lower mercury levels than albacore.

• Sardines, salmon, and anchovies are low in mercury: These smaller fish are excellent, low-mercury alternatives, offering great nutritional value with minimal risk.

• Variety is key to minimizing exposure: To reduce mercury intake, consume a variety of fish and prioritize options from the FDA's 'Best Choices' category.

• Pregnant women and children need extra caution: Sensitive populations should adhere to specific consumption recommendations and focus on the lowest-mercury options to protect developing nervous systems.

The Science Behind Mercury in Fish

Mercury is a naturally occurring element that enters the marine ecosystem through both natural events and human activities. Once in the water, bacteria convert it into methylmercury, a highly toxic form that accumulates in fish and shellfish. The level of mercury in a fish is primarily influenced by two factors: its position in the food chain and its lifespan. Larger, predatory fish at the top of the food chain consume many smaller fish over their lifetime, causing methylmercury to build up in their tissues. Older, larger fish generally have had more time to accumulate mercury. This bioaccumulation process is key to understanding why some types of canned fish are more of a concern than others.

Canned Tuna and Its Mercury Variations

Tuna is one of the most widely consumed canned fish, but mercury levels differ greatly among its species. The type of tuna listed on the can is crucial for determining its mercury content.

Albacore vs. Skipjack

• Canned Albacore Tuna: Often labeled as "white tuna," albacore tuna has nearly three times the mercury content of canned light tuna. Healthline reports the average mercury concentration in canned albacore at 0.350 ppm. Due to its higher mercury level, the Environmental Defense Fund (EDF) suggests limiting consumption, especially for children and pregnant women.
• Canned Light Tuna: This category typically consists of the smaller skipjack species. The FDA found the average mercury concentration in canned light tuna to be 0.126 ppm, making it a much safer choice for regular consumption. Skipjack tuna is a smaller, faster-growing species, so it accumulates less mercury over its shorter lifespan.

Mackerel: Choose Wisely

Just like tuna, not all canned mackerel is created equal when it comes to mercury content. It is important to know which species you are eating.

Atlantic vs. King Mackerel

• Canned Atlantic Mackerel: This species is typically low in mercury and is a safe, nutrient-dense choice. Sources confirm that Atlantic mackerel is rich in omega-3 fatty acids and protein, with mercury levels low enough for regular consumption.
• King Mackerel: This large, aggressive predator accumulates high levels of mercury. The FDA recommends that pregnant women, nursing mothers, and young children avoid king mackerel completely. While not a common option for typical canning, it is sometimes found in specialty canned seafood products.

Canned Fish Lowest in Mercury

For those seeking the lowest mercury options, several canned fish are considered excellent choices. The FDA places these species in its "Best Choices" category due to their low contaminant levels.

• Sardines: These small, forage fish are at the bottom of the food chain, meaning they consume plankton rather than other fish. The FDA reports their average mercury concentration is exceptionally low at 0.013 ppm. Canned sardines are a great source of omega-3s, calcium, and protein.
• Salmon: Canned salmon, which is usually pink or sockeye, is very low in mercury. A study cited by Yahoo found its average mercury level to be 0.014 ppm, even lower than fresh salmon. Its rich omega-3 content makes it a healthy and safe choice.
• Anchovies: Similar to sardines, anchovies are small, plankton-eating fish with a very short lifespan. This keeps their mercury levels minimal, with an FDA-reported average of 0.016 ppm. Anchovies are often preserved in salt, so monitoring sodium intake is important.

Comparison Table: Mercury Levels in Canned Fish

Canned Fish Type	Mercury Concentration (Average PPM)	Mercury Level	Recommended Consumption*	Primary Considerations
Albacore Tuna	0.350	Moderate to High	Limit to 1 serving per week	Higher mercury than light tuna
Light (Skipjack) Tuna	0.126	Low	2-3 servings per week	Much safer than albacore
Sardines	0.013	Very Low	Excellent choice	High in omega-3s, low in mercury
Salmon	0.014	Very Low	Excellent choice	Great omega-3 source, lower mercury than fresh
Atlantic Mackerel	0.05	Low	2-3 times per week	Good source of nutrients, but check sodium
Anchovies	0.016	Very Low	Excellent choice	Low mercury, but can be high in sodium

*Based on general recommendations for adults; specific groups like pregnant women have stricter guidelines.

How to Reduce Your Mercury Exposure from Canned Fish

1. Prioritize Low-Mercury Options: Make sardines, canned salmon, and anchovies your primary canned fish choices. They offer great nutritional benefits with minimal mercury risk. Tuna should be chosen with care. Always opt for 'canned light' or 'skipjack' tuna over 'white' or 'albacore' varieties.
2. Vary Your Seafood Intake: The Environmental Defense Fund (EDF) and FDA suggest eating a variety of fish and shellfish to minimize potential exposure to contaminants. Incorporating a mix of seafood from different sources helps reduce the risk of overconsumption from any single type.
3. Check Labels and Sources: For canned tuna, confirm the species if not explicitly labeled. Look for smaller, younger fish harvested in sustainably managed fisheries, which generally correlates with lower mercury levels.

Conclusion

When considering which canned fish is high in mercury, canned albacore tuna is the primary concern due to its higher levels compared to other popular canned options like light tuna, salmon, and sardines. The general rule of thumb is that larger, longer-living predatory fish will have higher concentrations of mercury due to bioaccumulation. By choosing smaller species like sardines, salmon, and skipjack tuna, you can enjoy the nutritional benefits of canned fish—including omega-3 fatty acids and protein—while minimizing your exposure to mercury. Moderation and variety are key to safely including canned fish in your diet.

Which Canned Fish is High in Mercury? List of Canned Fish

• Albacore Tuna: Canned albacore, or "white tuna," contains significantly more mercury than canned light tuna, and its consumption should be limited, especially for pregnant women and children.
• King Mackerel: Though not commonly canned, this species is very high in mercury and should be avoided entirely by sensitive groups.
• Yellowfin Tuna: Sometimes used in canned products labeled as "gourmet" or "tonno," yellowfin has higher mercury levels than skipjack and should be consumed in moderation.
• Chunk Light (Skipjack) Tuna: Generally low in mercury and a much safer choice than albacore for regular consumption.
• Sardines: Considered a "best choice" due to their very low mercury levels.
• Canned Salmon: A great low-mercury option, often with even lower levels than fresh salmon.
• Anchovies: These small fish have very low mercury concentrations.
• Atlantic Mackerel: A good low-mercury choice, unlike its larger relative, the king mackerel.

What to Eat Instead

If you are looking to replace higher-mercury options, there are plenty of alternatives that offer excellent nutrition with far lower mercury risk. Consider options such as:

• Canned Sardines: A fantastic source of omega-3s, calcium, and vitamin D with minimal mercury.
• Canned Salmon: Provides high levels of omega-3s and protein with a very low mercury content.
• Canned Mackerel (Atlantic): A nutritious option with low mercury levels, offering a similar taste profile to tuna.
• Shrimp and Scallops: These are very low in mercury and can be good sources of protein and other nutrients.
• Tilapia and Catfish: Also low-mercury choices if you prefer a milder flavor.

Authoritative Sources

To further inform your choices, consulting official health and environmental sources is essential. The U.S. Environmental Protection Agency (EPA) provides guidance on fish consumption, as does the FDA. Organizations like the Environmental Defense Fund (EDF) offer a seafood selector tool to help consumers make informed decisions. Always check for local advisories regarding fish caught recreationally.

Conclusion

Understanding which canned fish contains higher levels of mercury is vital for making healthier dietary choices. Larger predatory fish like albacore tuna carry more mercury than smaller fish like sardines, salmon, and skipjack tuna. By opting for these low-mercury alternatives and diversifying your seafood intake, you can reap the significant nutritional benefits of canned fish without unnecessary mercury exposure. For pregnant women, nursing mothers, and young children, following specific FDA guidelines is particularly important to protect developing nervous systems from harm.

Frequently Asked Questions

Which type of canned tuna has the highest mercury?

Canned albacore tuna, also known as 'white tuna,' contains the highest mercury levels among common canned tuna varieties. It is a larger species than skipjack, leading to more mercury accumulation over its lifespan.

Is canned salmon high in mercury?

No, canned salmon is not high in mercury. It is considered a low-mercury seafood option and is a very safe choice, even for frequent consumption.

How do sardines compare to tuna in terms of mercury?

Sardines have significantly lower mercury levels than most canned tuna, especially albacore. The FDA reports the average mercury concentration in sardines is 0.013 ppm, compared to 0.350 ppm in canned albacore tuna.

What is the safest canned fish to eat regarding mercury?

The safest canned fish to eat regarding mercury are typically smaller species like sardines, anchovies, and salmon. The FDA considers these 'Best Choices' due to their very low mercury content.

Should pregnant women avoid all canned fish due to mercury?

Pregnant women should not avoid all canned fish. Health authorities recommend eating low-mercury fish like canned light tuna, salmon, and sardines, while limiting or avoiding high-mercury species like albacore tuna.

Why do some fish have more mercury than others?

Mercury levels depend primarily on a fish's size, age, and position in the food chain. Larger, predatory fish live longer and consume more smaller fish, leading to a bioaccumulation of methylmercury in their tissues.

How often can I safely eat canned light tuna?

For most adults, it is safe to eat two to three servings of canned light tuna per week. However, specific recommendations may vary for sensitive populations, so it's always best to check current health guidelines.