Which Fish Is Most Nutritious? Mackerel, Salmon, and the Best Value Choices

Which Fish Is Most Nutritious? Mackerel, Salmon, and the Best Value Choices

Imagine walking through a supermarket seafood section. Salmon fillets are displayed prominently, tuna steaks look appealing, and expensive shellfish attract plenty of attention. Meanwhile, inexpensive mackerel sits quietly in the freezer, often overlooked.

Does a higher price mean better nutrition? Not necessarily.

A study published in Frontiers in Nutrition in November 2025 examined the nutrient density and affordability of fish and shellfish using the FAO/INFOODS uFISH database. Its findings challenged some familiar assumptions: mackerel ranked first among the fish and shellfish species evaluated for the NRF9.2 nutrient-density score, while tilapia, mackerel, and mussels were among the strongest affordable choices.

This does not mean mackerel is automatically the healthiest fish for everyone. Different species provide different nutrients, and factors such as mercury levels, preparation methods, portion sizes, and price all matter.

Let’s examine what the research actually found and how to use it when choosing fish.

🏆 What Makes a Fish Nutritionally Valuable?

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A fish can be rich in protein but relatively low in omega-3 fatty acids. Another may provide substantial vitamin D but contain more mercury than is desirable for frequent consumption.

To compare foods more systematically, researchers use nutrient-profiling methods.

Understanding the NRF9.2 Index

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The 2025 study used a version of the Nutrient Rich Food index called NRF9.2, designed specifically for aquatic foods.

It considers nine nutrients:

1. Protein
2. Calcium
3. Iron
4. Potassium
5. Magnesium
6. Selenium
7. Vitamin A
8. Vitamin D
9. Omega-3 fatty acids

The model calculates nutrient contributions relative to daily values, using a 100-gram edible portion. It also accounts for two nutrients that should generally be limited: saturated fat and sodium.

This is important because the index does not simply reward a food for containing a very high amount of one nutrient. It attempts to assess a broader nutritional profile.

However, an NRF9.2 score is not a complete measure of healthfulness. It does not capture every nutrient, contaminant, dietary need, or individual health consideration. A high score also does not mean that a food should be eaten without limits.

What Did the 2025 Study Find?

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The researchers analyzed aquatic foods in the FAO/INFOODS uFISH database and reported the following NRF9.2 rankings:

Mackerel achieved the highest score among the species categories evaluated. Small pelagic fish also ranked highly as a broader group.

The researchers found that mackerel, tilapia, mussels, and squid offered particularly strong combinations of nutrient density and affordability.

One important qualification: the study’s rankings reflect the food-composition data and species categories available in the database. They should not be interpreted as a universal ranking of every fish sold in every country.

The main lesson is that affordable fish can provide excellent nutrition. Expensive seafood is not automatically nutritionally superior.

🐟 1. Why Mackerel Ranked So Highly

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Mackerel is a nutrient-dense fish that provides high-quality protein, omega-3 fatty acids, vitamin D, selenium, and vitamin B12.

Its nutritional profile makes it a practical choice for people who want to obtain several important nutrients from one food.

Rich in EPA and DHA Omega-3 Fatty Acids

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Mackerel is an oily fish, meaning that a meaningful portion of its fat consists of polyunsaturated fatty acids, including the long-chain omega-3 fatty acids EPA and DHA.

These two fatty acids have different but complementary biological roles:

• DHA (docosahexaenoic acid): An important structural component of cell membranes, particularly in the brain and retina.
• EPA (eicosapentaenoic acid): Plays a role in cell signaling and the regulation of inflammatory processes.

Both contribute to normal physiological functions, and eating fish containing EPA and DHA can help increase their dietary intake.

Mackerel is not the only good source. Salmon, sardines, herring, and trout also provide valuable omega-3 fatty acids.

For most people, eating fish is a practical way to obtain these nutrients without relying on supplements. For more on the distinction between whole fish and fish oil products, see Supplementation and Coronary Heart Disease.

A Useful Source of Vitamin D

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Vitamin D is relatively scarce in many commonly eaten foods, making oily fish particularly valuable.

According to USDA food-composition data, cooked Atlantic mackerel provides approximately 16 micrograms of vitamin D per 100 grams, although the exact amount varies with species and preparation.

Salmon is another useful source, with vitamin D content varying substantially by species and whether the fish is wild or farmed.

Vitamin D contributes to:

• Calcium and phosphorus absorption.
• Bone and muscle function.
• Normal immune-system function.

Eating vitamin-D-rich fish can help improve dietary intake, particularly for people who consume few other sources. However, fish alone may not meet everyone’s vitamin D requirements.

Other Important Nutrients

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Mackerel also supplies:

• Vitamin B12: Supports normal nerve function and red blood cell formation.
• Selenium: Helps maintain antioxidant enzyme activity and normal thyroid function.
• Protein: Provides essential amino acids needed for tissue maintenance and repair.
• Other minerals: Depending on the species and edible portion, mackerel contributes nutrients such as phosphorus and potassium.

Its appeal is therefore not based on omega-3 alone. It provides a combination of protein, vitamins, and minerals in a relatively affordable food.

Not All Mackerel Is the Same

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This distinction is particularly important when discussing mercury.

The name “mackerel” covers multiple species. Atlantic mackerel (Scomber scombrus) and chub mackerel (Scomber colias) are not the same as king mackerel (Scomberomorus cavalla).

Their mercury levels can differ substantially.

The US Food and Drug Administration classifies:

• Atlantic mackerel: Best Choice for lower-mercury fish.
• Spanish mackerel: Good Choice.
• King mackerel: Choice to Avoid because of its high mercury levels.

Therefore, it is inaccurate to say that all mackerel is low in mercury. Check the exact species and its source, especially when buying fish under a generic market name.

💰 2. Cheap Fish Can Be Excellent Value

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The 2025 study also examined affordability, asking a practical question: how much nutritional value does each aquatic food provide relative to its price?

The researchers combined nutrient-density information with price data from the FAO’s Globefish database.

Mackerel, tilapia, mussels, and squid performed particularly well in the affordability analysis.

Why Did Mackerel Perform So Well?

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Mackerel combines several useful characteristics:

• It provides high-quality protein.
• It is rich in EPA and DHA.
• It can supply substantial vitamin D.
• It contains selenium and vitamin B12.
• It can be relatively inexpensive compared with some premium seafood products.

This combination makes it an attractive choice for everyday meals.

However, the study’s prices were based on international database information, not a universal supermarket price list. Actual costs vary according to location, season, supply, species, processing, and whether the fish is fresh, frozen, or canned.

Other Affordable Choices Worth Considering

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Mackerel is not the only value option. Several other aquatic foods offer strong nutritional value.

• Tilapia: An affordable source of high-quality protein. It is generally lower in fat and omega-3 than oily fish, but can be a useful everyday protein choice.
• Mussels: Provide protein, vitamin B12, iron, and other minerals. They are particularly useful for people looking to increase their intake of certain micronutrients.
• Squid: Supplies protein and several minerals, often at a reasonable price.
• Sardines: Provide omega-3 fatty acids, vitamin D, and, when eaten with their soft bones, calcium.
• Herring: Another oily fish that provides EPA, DHA, and other nutrients.

A varied seafood diet can provide a broader range of nutrients than relying on one fish alone.

⚖️ 3. What About Fish That Rank Lower?

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A lower nutrient-density score does not mean a fish is unhealthy, unsafe, or nutritionally worthless.

Some fish are excellent sources of protein but contain less vitamin D or omega-3 than oily species. Others may provide useful nutrients while being less affordable.

The important question is whether a fish suits your nutritional goals.

Basa and Pangasius: Affordable Protein, Less Omega-3

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Basa is a freshwater fish commonly associated with the pangasius group and is widely sold as a frozen fillet.

It has several practical advantages:

• Mild flavor.
• Relatively low cost.
• High-quality protein.
• Convenient boneless portions.

However, basa is generally a lean fish and provides less EPA and DHA than oily fish such as mackerel, sardines, and salmon.

That does not make it a poor food. It simply serves a different nutritional purpose.

Some frozen seafood products are treated with water-retaining ingredients, including phosphates, to improve texture and moisture retention. These treatments are not automatically unsafe, but they can affect product weight and nutritional comparisons.

Check ingredient lists and nutrition labels, particularly for sodium and added ingredients.

Also, be careful with seafood names. “Sole” refers to a group of flatfish, while basa is a different type of fish. Product names and market labeling can vary, so check the species identification rather than relying on a broad sales description.

Tuna, Swordfish, and Shark: Consider Mercury

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Large predatory fish can accumulate mercury through the food chain.

Mercury exposure is especially important during pregnancy, breastfeeding, and childhood because of its potential effects on neurological development.

Some species require particular caution:

• Swordfish
• Shark
• King mackerel
• Bigeye tuna
• Marlin

This does not mean that all tuna should be avoided. Canned light tuna, which generally includes skipjack, is classified as a lower-mercury Best Choice by the FDA. Albacore and yellowfin tuna are classified as Good Choices.

The FDA’s fish advice provides a useful reference for choosing seafood according to mercury exposure.

Hairtail: A Familiar and Nutritious Option

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Hairtail, also known as ribbonfish or cutlassfish, is popular in many Asian cuisines.

It provides:

• High-quality protein.
• Some omega-3 fatty acids.
• Selenium and other minerals.
• A moderate amount of dietary fat, depending on the species and edible portion.

Its nutritional profile makes it a useful addition to a varied diet, although it is not necessarily comparable to mackerel in every nutrient category.

The silvery surface of hairtail is largely composed of guanine crystals and associated material. It is not necessary to scrape the fish aggressively during preparation. However, claims that this coating is a major source of lecithin or that removing it substantially reduces nutritional value should be treated cautiously.

People managing gout or elevated uric acid may also want to discuss seafood portions with their healthcare professional. Fish purine content varies, and individual dietary recommendations depend on the person’s condition and treatment.

🧠 4. Common Misconceptions About Choosing Fish

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Fish nutrition is frequently misunderstood. A few familiar assumptions deserve closer examination.

Myth 1: Expensive Fish Is Always More Nutritious

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Price reflects many factors beyond nutritional composition:

• Production and farming costs.
• Fishing and processing expenses.
• Transportation and cold-chain logistics.
• Brand positioning and consumer demand.
• Species availability and seasonality.

Salmon is a nutritious fish, but it is not automatically superior to mackerel, sardines, or other affordable oily fish.

A sensible shopping strategy is to compare species, portion sizes, nutritional information, and price rather than assuming that the most expensive option is the healthiest.

Myth 2: Wild Fish Is Always Healthier Than Farmed Fish

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Wild and farmed fish can differ in fat content, fatty acid composition, feed, and environmental exposure.

For example, farmed Atlantic salmon may have a higher total fat content than some wild salmon because of differences in feed and growth conditions.

However, it is too simplistic to claim that farmed salmon is nutritionally inferior because its feed contains vegetable oils.

Modern aquaculture feeds vary considerably, and farmed salmon can still provide substantial EPA and DHA. Its fatty acid profile depends on the feed formulation and production system.

Wild salmon also varies by species, season, and location.

The practical conclusion is that both farmed and wild salmon can be nutritious choices. Neither category is automatically better in every nutritional measure.

Myth 3: Deep-Sea Fish Is Always Better

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The term “deep-sea” is often used as a marketing description, but it does not guarantee superior nutritional value.

Some deep-water species are rich in beneficial fats, while others are relatively lean. Some large, long-lived predatory species also accumulate more mercury.

Instead of relying on labels such as “deep-sea,” “wild,” or “premium,” consider the actual species, nutrient profile, and contaminant guidance.

Myth 4: Milky-White Fish Soup Is the Most Nutritious

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Many people believe that the whiter a fish soup becomes, the more nutritious it must be.

This is a misunderstanding of food chemistry.

The milky appearance usually results from fat droplets and other suspended particles becoming emulsified in the liquid during vigorous boiling. These droplets scatter light, giving the soup its white appearance.

The color itself does not indicate high calcium content.

Most calcium in fish bones is present in mineral structures that dissolve only to a limited extent during ordinary cooking. Consequently, typical fish soup is not a particularly concentrated calcium source.

Milk, calcium-fortified alternatives, calcium-set tofu, and small fish eaten with their bones are generally more dependable dietary calcium sources.

Fish soup can still provide flavor, fluid, and some nutrients, but the fish meat is usually the more substantial source of protein.

Myth 5: Cooking Fish Destroys All Its Omega-3

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Cooking can affect nutrients, but it does not eliminate all omega-3 fatty acids.

The amount retained depends on:

• Cooking temperature.
• Cooking duration.
• Exposure to air.
• Whether the cooking liquid or oil is discarded.
• The original fat content of the fish.

Steaming, baking, and moderate-temperature pan-cooking are practical options. Deep-frying can add substantial calories and may expose fats to high temperatures.

There is no need to eat fish raw to obtain its nutritional benefits.

🍳 5. How to Choose and Cook Fish Properly

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A nutritious fish is only a good choice if it is handled and prepared safely.

Choosing Fresh Fish

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When buying fresh fish, look for:

• Appearance: Flesh should look moist and reasonably firm, without excessive discoloration.
• Smell: Fresh fish should have a mild, clean smell rather than a strong sour, ammonia-like, or putrid odor.
• Storage: Fish should be properly refrigerated or displayed on sufficient ice.
• Packaging: Avoid packages that are leaking, damaged, or show signs of improper handling.

Clear eyes and moist gills can be useful observations for whole fish, but they are not guarantees of safety. Proper temperature control and reliable handling are more important.

For frozen fish, choose intact packaging without signs of thawing and refreezing, such as excessive ice crystals or damaged seals.

Good Cooking Methods for Mackerel

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Mackerel has a naturally rich flavor, so it does not require complicated preparation.

Pan-searing

1. Pat the fish dry with a clean paper towel.
2. Season lightly with salt, pepper, and lemon.
3. Heat a small amount of oil in a pan.
4. Cook until the flesh is opaque and flakes easily.
5. Turn as needed to ensure the fish is cooked through.

Steaming

Steaming preserves moisture and requires little added fat. Ginger, scallions, garlic, and a small amount of citrus can add flavor.

Baking or grilling

These methods work well for oily fish. Avoid excessive charring, and cook the fish thoroughly.

Tomato-based stewing

Mackerel pairs well with tomatoes, onions, and herbs. This is a useful way to include vegetables in the same meal.

Food Safety: Understand Histamine Poisoning

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Mackerel belongs to a group of fish that can cause scombroid, or histamine, poisoning when improperly handled.

Certain bacteria can convert naturally occurring histidine in fish muscle into histamine when the fish is exposed to unsuitable temperatures.

Symptoms can include:

• Facial flushing.
• Headache.
• Itching or rash.
• Palpitations.
• Nausea or diarrhea.
• A burning or tingling sensation around the mouth.

This reaction can resemble a fish allergy, although the underlying mechanism is different.

One crucial safety point: once histamine has formed, cooking, freezing, or reheating cannot reliably destroy it. Proper refrigeration or rapid freezing before histamine develops is therefore essential.

Buy fish from reputable suppliers, keep it cold during transport, refrigerate or freeze it promptly, and thaw frozen fish safely in the refrigerator or using an appropriate cold-water method.

Cooking thoroughly is important for controlling many foodborne pathogens, but it cannot make fish that has already accumulated dangerous levels of histamine safe to eat.

🥗 6. How Often Should You Eat Fish?

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For many adults, eating fish about twice a week is a practical way to obtain protein and beneficial fatty acids.

The FDA and Environmental Protection Agency recommend that people who are pregnant or breastfeeding, or who might become pregnant, choose 2–3 servings per week from lower-mercury fish categories. Children also have age-appropriate serving recommendations.

For general meal planning, consider rotating several species:

The best mix depends on availability, budget, dietary needs, and mercury guidance.

People who are pregnant, breastfeeding, or feeding young children should follow the relevant local fish-consumption advice rather than assuming that every mackerel or tuna species is interchangeable.

❤️ The Bottom Line: Choose Fish for Nutrition, Not Marketing

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The 2025 FAO uFISH-based study offers a useful reminder: mackerel is an outstanding combination of nutrient density and affordability, but it is not the only nutritious seafood choice.

The findings highlight several practical options:

• Mackerel: A strong all-around choice for protein, omega-3 fatty acids, vitamin D, and affordability.
• Tilapia: An affordable source of lean protein.
• Mussels: A useful source of iron, vitamin B12, and other micronutrients.
• Salmon and sardines: Excellent options for people seeking omega-3 fatty acids.
• Squid: A protein-rich seafood option that can offer good value.

Avoid judging fish solely by price, color, or marketing labels. Pay attention to the actual species, mercury guidance, nutritional composition, and storage conditions.

A varied seafood diet, prepared with sensible cooking methods, can provide valuable nutrients without requiring expensive purchases.

Sometimes the most nutritious choice is not the fish with the biggest price tag. It is the one that delivers excellent nutrition, fits your budget, and can be enjoyed safely and regularly.