What is the healthiest part of a fish?

December 10, 2025 •

4 min read

Many people often discard certain parts of a fish, unaware that some of the most concentrated nutrients are found outside the traditional fillet. Determining what is the healthiest part of a fish involves examining its skin, roe, head, and liver, as each offers a unique nutritional powerhouse for different health needs.

Quick Summary

The healthiest part of a fish is not a single answer, as nutrient profiles vary by species and component. Key nutritional benefits, including omega-3s, protein, and vitamins, are found in the skin, head, and roe, not just the fillet.

Key Points

Skin-on for More Omega-3s: For fatty fish like salmon, eating the skin on significantly increases your omega-3 intake, offering nearly twice as much as a skinless fillet.
Collagen for Skin and Joints: Fish skin and head cartilage are rich sources of collagen, a protein vital for improving skin elasticity and supporting joint health.
Roe (Eggs) as a Nutrient Powerhouse: Fish roe is a dense source of omega-3 fatty acids, protein, vitamin B12, and selenium, although it can be high in sodium and cholesterol.
Bones and Head for Minerals: Simmering fish heads and bones creates a nutrient-rich broth packed with calcium, phosphorus, and other minerals that benefit bone health.
Liver is Rich in Vitamins A & D: The liver of lean fish, like cod, is where fat-soluble vitamins are stored, providing an exceptionally high concentration of vitamins A and D, available via cod liver oil.
Source Matters for Safety: No matter which part you consume, it's essential to source fish from clean waters to minimize exposure to pollutants like mercury.

The Verdict on the Healthiest Part of a Fish

While the fillet is the most commonly consumed part of a fish, providing excellent lean protein and varying levels of healthy fats, it is not the sole, or even the single healthiest, component. The answer to what is the healthiest part of a fish depends on what specific nutrients you are seeking. For example, the skin of a fatty fish contains a much higher concentration of omega-3s than the muscle alone, while the liver of lean fish is packed with vitamins A and D. To get the most comprehensive nutritional value, adopting a 'nose-to-tail' approach and utilizing the whole fish, where safe, is the most beneficial strategy.

Breaking Down the Nutritional Value by Fish Part

The Flesh (Fillet)

The fish fillet is an excellent source of high-quality, easily digestible protein, essential for muscle repair and growth. The fat content varies significantly between species. Fatty, cold-water fish like salmon, mackerel, and herring store lipids and omega-3 fatty acids directly in their muscle tissue, making the fillet incredibly nutritious. Leaner fish, such as cod and haddock, store their fat primarily in their liver, resulting in a much lower fat content in the fillet. Therefore, for a boost in omega-3s, fatty fish fillets are superior, but for low-calorie, high-protein intake, lean fillets are ideal.

The Skin

Often discarded, fish skin is a nutritional treasure trove. It contains high-quality protein and is particularly rich in collagen, a structural protein that supports skin elasticity and joint health. The skin of fatty fish also provides a significant concentration of heart-healthy omega-3 fatty acids and antioxidants like vitamin E. Properly sourced and cooked fish skin can add a delicious, crispy texture to meals while boosting overall nutrient intake. However, it is crucial to source fish from clean waters to avoid pollutants like mercury that can accumulate in the skin.

The Roe (Eggs)

Fish roe, or fish eggs, are a delicacy packed with nutrients. A single serving can provide a dense dose of omega-3 fats, protein, and powerful antioxidants. Roe is also an exceptional source of vitamin B12, crucial for nerve function and energy production, and selenium, which strengthens the immune system. While highly nutritious, fish roe can be high in both cholesterol and sodium, so moderation is key, especially for those with related health concerns.

The Head

For the more adventurous eater, the fish head offers a wealth of nutrients. The eyes and brain are rich sources of omega-3 fatty acids, particularly DHA, which is essential for cognitive function and brain health. The bones and cartilage, often used in broths and stocks, provide excellent sources of calcium and phosphorus for strong bones and teeth. Simmering fish heads creates a nutrient-rich broth filled with minerals and collagen, beneficial for digestion and joint health.

The Liver

In certain lean fish like cod, the liver is the primary storage site for fat-soluble vitamins. Cod liver oil is a well-known supplement precisely because of its extremely high concentrations of vitamins A and D, as well as omega-3 fatty acids. Vitamin D is vital for calcium absorption and immune function, while vitamin A supports vision and skin health. For those who don't eat the liver directly, its oil can be a convenient way to access these concentrated nutrients.

Comparison Table: Nutritional Breakdown of Fish Parts


Feature	Flesh (Fillet)	Skin	Roe (Eggs)	Head	Liver
Omega-3s	High (in fatty fish)	Very High (in fatty fish)	Very High	High (brain & eyes)	Very High (in lean fish)
High-Quality Protein	Excellent source	Excellent source	Excellent source	Excellent source	Excellent source
Collagen	Low	High	Low	High (cartilage)	Low
Vitamins A & D	Low to Moderate	Moderate (Vitamin E)	High (D)	Moderate (A & D)	Very High
Calcium & Phosphorus	Low	Low	Moderate	High (bones)	Low

Making the Healthiest Choice: A Holistic Approach

Rather than fixating on a single part, the healthiest approach to eating fish is to consider the whole organism. Combining different components in your diet can provide a more balanced and diverse nutrient intake. For instance, enjoying a skin-on salmon fillet provides a double dose of omega-3s and collagen, while preparing a stock from the head extracts minerals and beneficial fats. When sourcing fish, always prioritize varieties from clean, unpolluted waters to minimize exposure to contaminants, regardless of which part you consume. The NHS recommends consuming at least two portions of fish per week, with one being oily fish, as part of a healthy diet.

Conclusion: It's Not a Simple Answer

Ultimately, there is no single "healthiest part of a fish," as different parts excel in different nutritional aspects. The skin offers a boost in omega-3s and collagen, the roe is a vitamin-rich superfood, the head provides minerals and brain-boosting fatty acids, and the liver is a concentrated source of vitamins A and D. While the fillet remains a stellar source of protein, embracing a broader consumption of the fish can maximize your nutritional intake. By being mindful of your source and incorporating various components, you can unlock the full spectrum of health benefits fish has to offer.

Frequently Asked Questions

Yes, fish skin is generally safe to eat, provided it comes from a responsibly sourced fish from clean waters. It is also important to avoid species with thick, leathery, or prickly skin, such as swordfish and monkfish.

The skin, roe (eggs), and head (specifically the brain and eyes) are particularly high in omega-3 fatty acids. Fatty fish fillets are also a well-known source, but the concentration in the skin can be higher.

Yes, making broth from fish bones and heads is very healthy. This process extracts valuable minerals like calcium and phosphorus, as well as collagen, creating a nutrient-dense and flavorful stock.

While most parts of a fish are edible and nutritious, some, like sharkskin, can be unpleasant due to high uric acid content. It is also recommended to avoid eating any part of a fish that comes from polluted water, as toxins can accumulate in the flesh and skin.

Fish roe is very nutritious, offering a high content of omega-3s, protein, and vitamins like B12. However, it is also high in cholesterol and sodium, so it should be consumed in moderation, especially by those with heart health concerns.

Farmed fish skin can be safe to eat, but it is important to be cautious. Sourcing from farms with good practices that avoid chemicals and antibiotics is key to minimizing potential contaminants.

Fish liver oil, such as cod liver oil, is a supplement prized for its high content of vitamins A and D. These vitamins support bone health, immune function, vision, and skin health, among other benefits.