What are the safest fish to eat?

According to the FDA, nearly all fish and shellfish contain traces of methylmercury, but the levels vary significantly. Knowing what are the safest fish to eat is crucial for minimizing your exposure to this toxin while still enjoying the rich nutrients, like omega-3s, found in seafood. This guide helps you navigate your choices for a healthier plate.

Quick Summary

This guide covers low-mercury fish like salmon, sardines, and tilapia, explains why certain large predatory fish should be limited, and offers practical tips for choosing and preparing seafood safely. It outlines how to select healthy and sustainable options for a nutritious diet.

Key Points

• Opt for Low-Mercury Fish: Choose smaller, short-lived fish like salmon, sardines, and anchovies for the lowest mercury levels.

• Limit Large Predatory Fish: Avoid or severely restrict consumption of high-mercury species such as shark, swordfish, and king mackerel.

• Focus on Variety: A varied diet of low-mercury fish and shellfish ensures a broad range of nutrients and prevents the accumulation of any single contaminant.

• Consider Vulnerable Populations: Pregnant and nursing women, along with young children, should be particularly cautious about mercury intake and follow specific FDA guidelines.

• Choose Sustainable Sources: Look for certifications like MSC or check the Seafood Watch program to find environmentally responsible choices.

• Prioritize Cooking Safety: Always cook seafood to an internal temperature of 145°F to eliminate harmful bacteria and parasites.

Understanding the Risks: Mercury and Contaminants

Eating fish offers significant health benefits, including providing high-quality protein, essential omega-3 fatty acids, and key vitamins and minerals. However, concerns exist about mercury and other contaminants that can accumulate in seafood. Understanding the source of these risks is the first step toward making safe choices.

Why Mercury is a Concern

Methylmercury is a neurotoxin that can harm the nervous system, especially in developing infants and young children. This compound is absorbed by fish from their environment and builds up in their systems. The concentration of mercury tends to be higher in large, long-lived predatory fish at the top of the food chain. For most adults, moderate consumption of fish is safe, but vulnerable groups like pregnant or nursing women and young children must be more careful.

Other Contaminants to Watch For

Beyond mercury, some fish can accumulate other pollutants, such as polychlorinated biphenyls (PCBs) and dioxins. While regulations have reduced these contaminants, it's still wise to choose fish from clean, well-monitored waters. Choosing sustainably sourced seafood is often a good way to ensure a more responsible catch.

The Safest Fish to Eat: Low Mercury, High Nutrients

The FDA and EPA provide comprehensive guidance on which fish are safest to eat. Here is a list of excellent choices that are low in mercury and packed with nutrients:

• Salmon: An incredibly rich source of omega-3s, protein, and vitamin D. Wild-caught Alaskan salmon is often cited as a top sustainable and low-mercury choice.
• Sardines: These small, oily fish are very low in mercury and provide a powerful dose of omega-3s and calcium. Look for canned versions for convenience.
• Mackerel (Atlantic): The smaller Atlantic mackerel is a great, low-mercury source of omega-3s. Avoid the larger King mackerel, which has high mercury levels.
• Anchovies: Tiny and bursting with flavor and omega-3s, anchovies have one of the lowest mercury concentrations.
• Trout (Freshwater): This mild-flavored fish is another safe bet, especially when farmed responsibly in the U.S. or caught from clean waters.
• Tilapia: A lean, mild-tasting fish that is very low in mercury, making it a common and safe choice.
• Cod: Known for its firm, flaky, white flesh, cod is a great source of lean protein and is low in mercury.
• Shrimp: One of the most popular seafood options, shrimp is generally low in mercury and is a versatile choice.
• Catfish: Farmed catfish is a very safe option with low mercury levels.

Fish to Limit and Avoid

To minimize risk, it's important to be aware of the fish that contain higher mercury levels. The FDA specifically recommends avoiding certain types of fish, particularly for pregnant women and young children.

High Mercury (Avoid or limit severely):

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

Moderate Mercury (Limit intake): Some larger fish fall into a moderate-mercury category. While occasional consumption is acceptable for most adults, limiting these is prudent, especially for sensitive populations. This list includes:

• Albacore (white) tuna
• Yellowfin tuna
• Grouper
• Halibut
• Mahi Mahi

Comparison of Common Fish

Fish Type	Mercury Level	Omega-3s	Sustainability	Best For	Considerations
Salmon	Low	High	Varies by source; Wild Alaskan is often a 'Best Choice'.	All adults, pregnant women, and children.	Choose wild-caught over farmed for higher omega-3s and lower PCBs.
Sardines	Very Low	Very High	Generally sustainable.	People seeking high calcium and omega-3s on a budget.	Often canned, but very healthy.
Tuna (Canned Light)	Low	Moderate	Generally sustainable, particularly skipjack caught by pole and line.	General consumption; limit for pregnant women.	More omega-3s than albacore; contains less mercury.
Tilapia	Low	Low	Can be sustainable, often farmed.	General, low-risk protein source.	Wild-caught is preferable, but farmed can be safe when sourced responsibly.
Swordfish	Very High	Moderate	Stocks can be vulnerable to overfishing.	Limit to special occasions; avoid if pregnant or for young children.	Higher mercury risk due to size and lifespan.

Choosing Sustainable and Healthy Options

Making responsible seafood choices goes beyond just mercury levels. Considering sustainability ensures you're supporting healthy ocean ecosystems for the future. Look for certifications from organizations like the Marine Stewardship Council (MSC) or use the Monterey Bay Aquarium’s Seafood Watch program for guidance.

Shopping and Preparation Tips

• Buy from reputable sources: Purchase fish from a fishmonger with high turnover or from a grocery store with a good reputation. This increases the chances of freshness.
• Look for signs of freshness: Fresh fish should have a clean, mild scent, not an overly 'fishy' odor. Whole fish should have clear eyes and bright red gills.
• Check local advisories: For fish caught in local rivers or lakes, always check for local health advisories on potential contaminants.
• Cook properly: Thoroughly cooking fish and shellfish is essential to kill harmful bacteria and parasites. Ensure seafood reaches an internal temperature of 145°F.
• Reduce contaminants: Trimming fat and skin can reduce contaminant levels in some fish. Grilling or baking on a rack allows fat to drip away. Note that this method does not reduce mercury levels.

Conclusion: A Balanced Approach to Seafood

Balancing the nutritional benefits of fish with potential risks requires an informed approach. Prioritizing low-mercury, nutrient-rich varieties like salmon, sardines, and mackerel is key. Being mindful of consumption limits for moderate-mercury fish and avoiding high-mercury species altogether provides the foundation for safe seafood consumption. By choosing sustainable, responsibly sourced fish, you can enjoy this healthy protein while supporting a healthier planet. Variety is your best strategy, allowing you to reap the diverse benefits different species offer without concentrating contaminants. The overarching advice is clear: eat fish, but eat the right fish.

Authoritative Link: FDA/EPA Advice on What You Need to Know About Fish

Frequently Asked Questions

Which fish has the highest mercury levels?

The highest mercury levels are typically found in large, predatory, long-lived fish such as shark, swordfish, king mackerel, and tilefish from the Gulf of Mexico.

Is canned tuna safe to eat?

Canned light tuna (skipjack) is generally safe and low in mercury. Canned albacore (white) tuna has higher mercury levels, so intake should be more limited, especially for pregnant women and children.

What are the benefits of eating low-mercury fish?

Low-mercury fish are excellent sources of protein, vitamins D and B2, and essential omega-3 fatty acids, which support heart and brain health without the risk of high mercury exposure.

How often should you eat fish?

For most people, the American Heart Association recommends eating fish at least two times per week as part of a healthy diet. This is especially true for fatty, omega-3-rich fish.

Can pregnant women eat fish?

Yes, pregnant women should eat low-mercury fish (2–3 servings a week) to get valuable omega-3s for fetal development. However, they must avoid high-mercury fish and uncooked seafood.

How can I tell if a fish is fresh?

Fresh fish should have a mild, clean scent, not a strong 'fishy' smell. Whole fish should have clear, full eyes and bright, red gills.

Does cooking fish reduce its mercury content?

No, cooking fish does not reduce its mercury content. Trimming fat and skin can reduce other contaminants like PCBs, but mercury binds to the protein in the fish's flesh.