How Often Can You Eat Fish to Avoid Mercury Poisoning? Your Guide to Safe Seafood

November 8, 2025 •

3 min read

The FDA and EPA advise most Americans to eat 2-3 servings of fish per week for its significant health benefits. Knowing how often can you eat fish to avoid mercury poisoning requires understanding which types of seafood are low in mercury and which should be limited.

Quick Summary

Navigating safe fish consumption is crucial for minimizing mercury risk. This guide provides practical guidelines for all age groups, helping you choose seafood wisely.

Key Points

Vary Your Fish: Don't rely on just one type of fish; variety is key to lowering mercury risk, as per FDA and EPA guidelines.
Check the Levels: Classify fish into low, moderate, and high mercury categories to manage your consumption safely.
Smaller is Safer: Smaller, younger fish typically contain less mercury than larger, predatory species.
Consider Vulnerable Groups: Pregnant women, breastfeeding mothers, and young children should be extra cautious and primarily stick to low-mercury options.
Know the Symptoms: Be aware of mercury poisoning signs like tremors, numbness, and coordination issues, and consult a doctor if concerned.

The Importance of Fish in a Healthy Diet

Fish is an excellent source of lean protein, essential omega-3 fatty acids (DHA and EPA), and other vital nutrients like vitamin D, iodine, and selenium. These nutrients are crucial for brain development in infants, heart health in adults, and overall well-being. However, almost all fish contain some traces of methylmercury, a neurotoxin that can be harmful in high concentrations. The key to reaping the benefits while minimizing risk lies in informed choices and moderation.

How Mercury Accumulates in Fish

Mercury exists naturally in the environment, but industrial pollution from coal-burning and other sources increases its levels in water. In aquatic environments, bacteria convert elemental mercury into a more toxic form, methylmercury. This methylmercury then enters the food chain. Smaller fish absorb it, and as larger, predatory fish eat the smaller ones, the mercury accumulates in a process called biomagnification. This means large, long-lived predatory fish at the top of the food chain tend to have the highest concentrations of mercury, while smaller fish have less.

Official Guidelines for Safe Consumption

To protect public health, especially for vulnerable populations like pregnant women and children, health agencies like the FDA and EPA have issued specific consumption advice.

Best Choices: Eat 2-3 servings a week

For most adults, enjoying two to three servings (8 to 12 ounces) of low-mercury fish per week is generally safe and beneficial. A serving size is typically 4 ounces before cooking. Pregnant and breastfeeding women and young children are advised to stick to the lower end of this range, focusing exclusively on the "Best Choices" category.

Best Choices (Low Mercury) include:

Salmon
Sardines
Shrimp
Catfish
Pollock
Tilapia
Canned Light Tuna (Skipjack)

Good Choices: Eat 1 serving a week

These fish have moderate mercury levels. If you are pregnant or breastfeeding, or if you are a young child, you should limit these to no more than one serving per week, and have no other fish that week.

Good Choices (Moderate Mercury) include:

Albacore Tuna (canned white)
Halibut
Mahi Mahi
Snapper
Grouper
Bluefish

Choices to Avoid: Highest mercury levels

These large, predatory fish contain the highest levels of methylmercury and should be avoided by pregnant women, breastfeeding women, young children, and women planning to become pregnant. Other adults should limit consumption to minimize risk.

Choices to Avoid (Highest Mercury) include:

Shark
Swordfish
King Mackerel
Marlin
Orange Roughy
Bigeye Tuna
Tilefish (Gulf of Mexico)

Your Guide to Mercury Levels in Popular Fish


Fish Type	Mercury Level	Recommended Weekly Servings (Adults)	Notes
Salmon	Very Low	2-3 servings	Excellent source of omega-3s.
Canned Light Tuna (Skipjack)	Low	2-3 servings	Affordable and versatile.
Albacore Tuna (Canned White)	Moderate	1 serving	Higher mercury than light tuna.
Swordfish	Highest	Rarely, if ever	Avoid for vulnerable populations.
Shrimp	Very Low	2-3 servings	A safe and popular choice.
Tilapia	Very Low	2-3 servings	Another safe, low-mercury option.
Shark	Highest	Avoid	Highest mercury content; universally cautioned.

How to Further Reduce Your Exposure

Beyond following the established guidelines, there are additional steps you can take to minimize mercury exposure from fish:

Vary Your Fish: Don't rely on just one type of fish, even a low-mercury one. Varying your seafood choices spreads the risk across different species.
Eat Smaller, Younger Fish: Generally, larger and older fish have had more time to accumulate mercury. Opt for smaller specimens of a given species when possible.
Check Local Advisories: If you consume fish caught locally from lakes, rivers, or coastal areas, check with your state or local health department. Some local waters have specific fish consumption advisories due to mercury or other contaminants.
Choose Canned Wisely: Canned light tuna (typically skipjack) is a better choice than canned white (albacore) tuna if you eat it frequently, as it contains significantly less mercury.

Conclusion

Making informed choices about seafood consumption is the most effective way to enjoy the health benefits of fish while minimizing the risk of mercury exposure. Following the FDA and EPA's tiered guidance—by selecting "Best Choice" fish more often and strictly limiting or avoiding "Choices to Avoid"—allows you to confidently include fish in a healthy, balanced diet. Remember that the nutritional advantages of fish, particularly for brain development, are significant and outweigh the potential risks when consumed according to these guidelines. For more detailed information, you can reference the FDA's official advice about eating fish.

Frequently Asked Questions

The fish with the highest mercury levels are large, predatory species like shark, swordfish, king mackerel, marlin, orange roughy, and bigeye tuna. These should be limited or avoided.

It depends on the type. Canned light tuna (usually skipjack) is a "Best Choice" with lower mercury levels, while canned white (albacore) tuna is a "Good Choice" with higher levels that should be consumed less frequently.

No, cooking fish does not reduce its mercury content. Mercury accumulates in the fish's muscle tissue, so cooking methods like grilling or baking do not remove it.

The FDA recommends that pregnant women, breastfeeding women, and young children eat 2 to 3 servings per week (8 to 12 ounces) of fish from the "Best Choices" category, which is low in mercury.

Fish is a great source of protein and omega-3 fatty acids, which are beneficial for heart health and brain development. These benefits often outweigh the risks of mercury exposure if you choose fish wisely.

Yes, especially if you are pregnant, nursing, or giving fish to young children. The FDA lists several species to completely avoid, including shark, swordfish, king mackerel, and tilefish from the Gulf of Mexico.

Mercury levels in fish are primarily influenced by their diet and position in the food chain, not whether they are farmed or wild. Farmed salmon, for example, typically have low mercury levels, similar to their wild counterparts.