How much tuna can I eat per week in mercury?

January 3, 2026 •

4 min read

The Food and Drug Administration (FDA) recommends that pregnant or breastfeeding women and young children consume 8 to 12 ounces of lower-mercury fish per week, including canned light tuna. However, tuna contains varying mercury levels depending on the species, which means understanding consumption limits is crucial for your health.

Quick Summary

The amount of tuna you can safely eat weekly depends on the type, with canned light tuna allowing more servings than albacore due to lower mercury content. Guidelines and serving sizes also vary for different populations.

Key Points

Tuna Type Matters: Canned light tuna (skipjack) contains significantly less mercury than canned white (albacore) tuna or fresh tuna steaks.
Check FDA Guidelines: Adhere to the FDA's recommended weekly servings, which vary by tuna type and population group.
Pregnant Women and Children: These groups should limit their intake and prioritize lower-mercury options to protect developing nervous systems.
Vary Your Seafood: Diversify your diet with other low-mercury fish and shellfish like salmon, sardines, and shrimp to minimize overall mercury exposure.
Know the Serving Size: A standard adult serving of fish is about 4 ounces, and recommended weekly limits are based on this portion size.
Avoid High-Mercury Fish: Some tuna species, like Bigeye, have the highest mercury levels and should be avoided entirely, particularly by vulnerable groups.

Understanding Mercury in Tuna

Mercury is a naturally occurring element, but industrial pollution can increase its concentration in the environment. In water, it is converted into methylmercury by microorganisms. Fish then absorb this methylmercury as they feed, and it accumulates in their tissues. This process, known as bioaccumulation, is why larger, older, predatory fish, which are higher up the food chain, tend to have higher levels of mercury. The primary health concern is that high levels of methylmercury can affect the nervous system, with developing fetuses and young children being the most vulnerable.

Not all types of tuna contain the same amount of mercury. The key difference lies in the size and species of the fish. Smaller species like skipjack, which is typically used for canned 'light' tuna, contain less mercury. In contrast, larger species like albacore ('white') tuna and bigeye tuna have significantly higher levels. Canned tuna, in general, has lower mercury levels than fresh or frozen tuna steaks because the tuna used for canning are typically smaller and younger.

FDA Recommendations for Tuna Consumption

To help consumers make informed decisions, the U.S. Food and Drug Administration (FDA) categorizes fish and shellfish into three groups: 'Best Choices,' 'Good Choices,' and 'Choices to Avoid' based on their mercury content.

General Adult Guidelines

For a healthy adult, incorporating fish into a balanced diet is recommended for its protein and omega-3 fatty acids. Based on FDA guidelines, here is the recommended weekly consumption for different types of tuna:

Canned Light Tuna (Skipjack): Up to 12 ounces per week (two to three 4-ounce servings).
Canned White Tuna (Albacore): Limited to one 4-ounce serving per week.
Fresh Tuna Steaks (Yellowfin, Albacore, or Bluefin): Limit to one 4-ounce serving per week due to higher mercury levels than canned light tuna.

Special Populations: Pregnant Women and Children

Women who are pregnant, breastfeeding, or trying to become pregnant should be especially mindful of mercury intake, as it can be harmful to a developing baby's brain and nervous system. The FDA and EPA provide specific, cautious advice for this group.

Pregnant or Breastfeeding Women: Can consume up to 12 ounces of low-mercury fish, including canned light tuna, per week. They should limit albacore tuna to no more than 6 ounces per week.
Children (Ages 1–11): Should also follow the low-mercury guidelines. The FDA recommends varying serving sizes based on age. Children can eat two servings of canned light tuna per week, but albacore is not recommended for young children.

Comparison of Tuna Types and Mercury

Understanding the differences between tuna types is essential for managing your intake. The table below compares the average mercury concentration and recommended servings for common commercial tuna products.


Tuna Type	Average Mercury Concentration (ppm)*	Adult Weekly Servings (4 oz)	Special Population Weekly Servings (4 oz)	Key Points
Canned Light (Skipjack)	0.126	2-3	2-3 (Pregnant/Breastfeeding)	Made from smaller fish, lower mercury level.
Canned White (Albacore)	0.350	1	1 (Pregnant/Breastfeeding)	Higher mercury due to larger fish species.
Fresh/Frozen Yellowfin	0.354	1	Not recommended for children	Similar mercury to Albacore, varies by size.
Fresh/Frozen Bigeye	0.689	Avoid	Avoid entirely	Highest mercury levels among tuna species.

*ppm: parts per million

Safe Tuna Consumption Practices

Beyond simply knowing the numbers, there are practical steps you can take to enjoy the benefits of tuna while minimizing risk.

Vary Your Fish Intake: Don't rely solely on tuna. Incorporate other low-mercury, high omega-3 fish like salmon, sardines, and anchovies into your diet. This reduces your exposure to a single source of mercury.
Check Local Advisories: If you catch your own fish, be sure to check local fish advisories. The mercury levels in fish from specific lakes and coastal areas can vary widely.
Know Your Source: Some brands test for and guarantee lower mercury levels. Researching reputable brands can provide an extra layer of reassurance.
Cooking Does Not Remove Mercury: Cooking fish does not reduce its mercury content, so stick to the recommended serving limits regardless of how you prepare your tuna.

Low-Mercury Alternatives to Consider

If you are concerned about mercury or simply want to add variety to your diet, here are some excellent alternatives with low mercury levels:

Shrimp
Salmon
Scallops
Cod
Catfish
Crab
Sardines
Anchovies

Conclusion

While tuna is a convenient and nutritious source of protein and omega-3 fatty acids, it must be consumed thoughtfully due to its mercury content. The amount you can safely eat each week is highly dependent on the type of tuna you choose. By opting for canned light (skipjack) tuna over albacore and fresh varieties, and adhering to the FDA's serving recommendations, most healthy adults can enjoy tuna without significant risk. Individuals who are pregnant, breastfeeding, or serving children should be more cautious and follow the specific, lower limits to protect against developmental risks. Mixing your seafood choices with other low-mercury options is the best strategy for a healthy, balanced diet. For more information on mercury levels in fish, you can visit the FDA's official advice page.

Frequently Asked Questions

Canned light tuna is typically made from smaller skipjack tuna, which have lower mercury levels. Canned white tuna, or albacore, is from a larger species with higher mercury concentrations, so you should consume less of it.

Eating canned tuna every day is not recommended because consistent consumption can lead to a build-up of mercury over time. It is safer to follow the weekly serving guidelines and vary your protein sources.

Pregnant women should consume 8 to 12 ounces of low-mercury fish per week, including canned light tuna. They should limit albacore tuna to no more than 6 ounces per week and avoid high-mercury options like bigeye tuna.

Not necessarily. Fresh tuna steaks (like yellowfin or albacore) often come from larger, older fish that have higher mercury levels than the smaller skipjack tuna used in most canned light products. Canned light tuna is often the lowest mercury option.

Symptoms of high mercury exposure can include vision changes, tingling sensations, problems with balance or coordination, and impaired speech. If you suspect you have symptoms, you should contact a health care provider.

Mercury gets into fish through a process called bioaccumulation. Methylmercury, the organic form, is absorbed by fish from the water and builds up in their bodies. Larger, older fish accumulate more mercury over their lifespan.

Yes, children can eat tuna, but in smaller, age-appropriate portions. The FDA recommends limiting intake and prioritizing low-mercury options like canned light tuna, while avoiding higher-mercury types such as albacore.

If you exceed the recommended amount one week, you can simply cut back on your tuna intake for the next week or two. One week of higher consumption is not a significant concern, as mercury levels accumulate over time.