Which is the Healthiest Seafood to Eat? Your Ultimate Guide

November 3, 2025 •

4 min read

The American Heart Association recommends at least two servings of nonfried fish per week, rich in heart-healthy omega-3s. With a wide variety of choices available, understanding which is the healthiest seafood to eat involves looking beyond just omega-3s to also consider mercury levels and sustainability. This guide navigates the ocean of options to help you make the best choices for your health and the planet.

Quick Summary

The healthiest seafood options balance high omega-3s with low mercury levels, including smaller, oily fish like salmon and sardines, and bivalve shellfish such as oysters and mussels.

Key Points

Balance is Key: Prioritize seafood with high omega-3 fatty acids and low mercury levels, such as smaller, oily fish and shellfish.
Salmon is a Top Pick: As an excellent source of omega-3s and protein, both wild and farmed salmon are generally healthy options with low mercury.
Sardines are a Superfood: These small, low-mercury fish are packed with omega-3s, calcium, and vitamin D, especially when canned and eaten with bones.
Oysters Boost Immunity: Exceptionally high in zinc, oysters also offer protein, iron, and omega-3s, supporting heart and immune health.
Vary Your Choices: Eating a variety of low-mercury seafood, including options like mackerel and trout, ensures a broad spectrum of nutrients and minimizes contaminant exposure.
Cook Healthily: The best preparation methods are baking, grilling, or steaming, as frying can add unhealthy fats.

Understanding the Criteria for Healthy Seafood

Choosing the healthiest seafood is a matter of balancing nutritional benefits with potential risks like mercury contamination. The two most important factors are omega-3 fatty acid content and mercury levels. Other considerations include overall nutrient profile, cooking methods, and environmental sustainability.

The Importance of Omega-3 Fatty Acids

Omega-3s, particularly EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), are polyunsaturated fats essential for human health that our bodies cannot produce. They play a crucial role in:

Heart Health: Lowering blood pressure, reducing triglycerides, and decreasing the risk of heart attack and stroke.
Brain Function: Supporting cognitive function, memory, and reducing the risk of neurodegenerative diseases.
Anti-Inflammatory Properties: Reducing chronic inflammation, which is a factor in many chronic diseases.

Navigating Mercury Levels

Mercury is a neurotoxin that accumulates in fish, particularly larger predatory fish that sit higher on the food chain. To minimize exposure, health authorities recommend choosing seafood that is lower in mercury. Smaller fish have shorter lifespans and typically consume less mercury-containing prey, making them a safer option.

The Healthiest Seafood Contenders

Certain types of seafood consistently rank high for their combination of robust nutrition and low contaminant levels.

Salmon: The Omega-3 Powerhouse

Salmon is frequently cited as one of the healthiest fish to eat due to its high omega-3 content, protein, and array of vitamins and minerals.

Wild-caught vs. Farm-raised: While wild salmon may contain more minerals, farmed salmon often has higher omega-3 levels due to its diet. Both are considered good, low-mercury options.
Astaxanthin: The pinkish color comes from a powerful antioxidant called astaxanthin, which offers additional protective properties.

Sardines: The Tiny, Mighty Superfood

Canned sardines are a budget-friendly and convenient nutritional powerhouse. Since you eat the whole fish, including the soft bones, they provide exceptional levels of calcium and vitamin D.

High Omega-3s: Sardines are packed with omega-3s for heart and brain health.
Low Mercury: Their small size places them low on the food chain, meaning very low mercury accumulation.
Other Nutrients: They are also rich in vitamin B12, selenium, and iron.

Oysters: Rich in Zinc and B12

These bivalve mollusks offer impressive health benefits, particularly their extremely high zinc content, which is vital for immune function.

Zinc: A 100g serving can provide a significant portion of the daily recommended intake of zinc.
Other Minerals: Oysters are also a great source of iron, vitamin B12, and omega-3s, all contributing to heart and immune health.
Sustainable Choice: Oysters are a low-impact seafood, as farmed varieties filter and clean water.

Mackerel and Herring: The Oily Fish Duo

These oily fish are excellent sources of omega-3 fatty acids, protein, and selenium. Similar to sardines, they are small and therefore lower in mercury than larger fish. Atlantic mackerel is a good sustainable option.

Trout and Cod: Versatile and Nutritious

Rainbow trout is a sustainable choice that provides a healthy dose of omega-3s and vitamin D. Cod is a lean white fish, low in fat, but still offers protein and vitamins like B12.

Comparison of Healthy Seafood Options

To help you decide, here is a table comparing some of the healthiest choices based on key metrics.


Seafood Type	Key Nutritional Benefit	Mercury Level	Sustainability Notes	Other Vitamins/Minerals
Salmon (Wild/Farmed)	High Omega-3s, Protein	Low	Varies; check for certifications (e.g., ASC)	Vitamin D, Selenium, Potassium
Sardines (Canned)	High Omega-3s, Calcium, Vit D	Very Low	Very Sustainable	B12, Iron, Selenium
Oysters	Very High Zinc, Protein	Very Low	Often Positive Impact	B12, Iron, Copper, Selenium
Mackerel (Atlantic)	High Omega-3s, Selenium	Low	Atlantic Mackerel a good choice	B12, Protein, CoQ10
Trout (Rainbow)	Omega-3s, Vit D, B12	Low	Farmed rainbow trout is sustainable	Protein
Mussels	Omega-3s, Protein, Manganese	Very Low	Low-impact farmed option	B12
Light Canned Tuna	Omega-3s, Protein	Low (less than Albacore)	Pole and line caught is best	B12, Selenium

Best Practices for Eating Healthy Seafood

Incorporating seafood into your diet effectively involves preparation and variety.

Preparation: The healthiest way to cook seafood is to bake, grill, or steam it. Frying can increase the fat content, diminishing the health benefits.
Variety: Rotate your seafood choices to ensure you receive a broad spectrum of nutrients. A diverse diet also minimizes the risk of over-consuming any one contaminant.
Canned Options: Don't overlook canned fish. Canned salmon and sardines offer convenient and nutritious options with a long shelf life. When buying canned sardines, look for low-sodium versions.
Check Certifications: For sustainable options, look for certifications like the Marine Stewardship Council (MSC) or the Aquaculture Stewardship Council (ASC) on packaging.

Conclusion

While many types of seafood are beneficial, the answer to which is the healthiest seafood to eat often points to smaller, oilier fish and bivalves. Options like salmon, sardines, mackerel, and oysters provide a dense package of omega-3s, protein, and essential vitamins and minerals, all while carrying low mercury risks. By focusing on a diverse intake of these and other responsibly sourced, low-mercury choices, you can reap significant health rewards, from cardiovascular protection to improved brain function. The simplest rule is to prioritize variety and moderation in your seafood consumption, preparing it in healthy ways to get the maximum nutritional bang for your buck.

For more detailed information on contaminants and seafood recommendations, consult the FDA's advice on eating fish.

Frequently Asked Questions

Oily fish, like salmon and sardines, contain higher levels of healthy fats, including omega-3 fatty acids, throughout their flesh. White fish, such as cod and tilapia, are lower in fat overall, though they still offer high-quality protein.

Yes, many canned seafood options, especially sardines and salmon, are very nutritious. In some cases, like with canned sardines where the bones are soft enough to eat, you get additional nutrients like calcium and vitamin D.

Look for certifications on packaging from organizations like the Marine Stewardship Council (MSC) or the Aquaculture Stewardship Council (ASC). Smaller, faster-reproducing species like sardines, mussels, and oysters are often more sustainable.

Yes, larger predatory fish typically have higher mercury levels. The FDA recommends limiting or avoiding high-mercury options like swordfish, king mackerel, bigeye tuna, and shark.

Oysters are an exceptional source of zinc, which is crucial for immune system function. They also provide protein, iron, vitamin B12, and omega-3s, contributing to heart health and energy levels.

Yes, pregnant women can and should eat seafood, but they should choose low-mercury options. The FDA provides specific guidance, and low-mercury fish like salmon, sardines, and canned light tuna are good choices.

If oily fish isn't your preference, you can get omega-3s from other sources. Oysters and mussels contain some omega-3s, and non-seafood options include walnuts, flaxseed, and canola oil.