Best Fish For Omega 3
If there’s one reason nutritionists urge us to eat more fish, it’s omega-3. These remarkable fats — found in abundance in oily fish — are associated with supporting the heart, brain, eyes and the body’s healthy inflammatory balance, and our bodies can’t make them efficiently, so we need them from food. The very best source is genuinely fresh oily fish.
This guide covers everything: why omega-3 matters, the difference between EPA and DHA, the benefits from heart to pregnancy, and the top ten omega-3-rich fish — with the typical amount each one contains — plus how to cook fish without losing its goodness. As a family-run fishmonger, we hand-select oily fish at Billingsgate Market and deliver it fresh across London.
The essential fats
Why Omega-3 Matters
Omega-3 fatty acids are “essential” in the truest sense — vital for health, yet not made well by the body, so they must come from what we eat. Oily fish is the richest and best-absorbed dietary source there is.
The most valuable omega-3s in fish are the long-chain forms, EPA and DHA. Plant sources like flax provide a shorter-chain omega-3 (ALA) that the body converts only inefficiently — which is why oily fish, delivering EPA and DHA ready-made, is so uniquely valuable. Eating it regularly is one of the simplest, most enjoyable things you can do for long-term wellbeing.
EPA vs DHA
DHA (docosahexaenoic acid) is a major structural building block of the brain, nervous system and the retina of the eye. It’s especially important during pregnancy and childhood, when the brain and eyes are developing fastest — and it continues to support brain and eye health throughout life.
EPA (eicosapentaenoic acid) is particularly associated with supporting heart health and the body’s healthy inflammatory balance. The two work together, and oily fish conveniently provides both in a natural, well-absorbed form — another reason whole fish beats an isolated supplement.
Both, in every oily fish
Salmon, mackerel, sardines, herring and anchovies all deliver EPA and DHA together — nature’s complete omega-3 package.
Head to heart
The Benefits Of Omega-3
The reach of omega-3 is remarkable — few nutrients touch so many aspects of health. Here’s where it matters most.
Heart health
Omega-3s are among the most studied nutrients for cardiovascular wellbeing. A diet that includes oily fish is associated with supporting a healthy heart and healthy blood-fat levels — one reason oily fish is so widely recommended.
Brain function
DHA is a major structural fat in the brain. Omega-3s are associated with supporting healthy brain function across life, from a child’s development to maintaining sharpness in later years.
Eye health
DHA is a key building block of the retina, so omega-3 is associated with supporting healthy vision — a benefit that begins before birth and continues throughout life.
During pregnancy
Omega-3 DHA supports a baby’s brain and eye development, so oily fish is valuable in pregnancy — within guidance of up to two portions of oily fish a week, avoiding shark, swordfish and marlin and limiting tuna.
For children
Growing brains and eyes thrive on DHA, making oily fish a genuine childhood superfood — introduced from around six months, well-cooked and deboned. See our guide to the best fish for children.
Calming inflammation
Omega-3 fatty acids are associated with supporting the body’s healthy inflammatory balance, part of the reason a diet rich in oily fish is linked with long-term wellbeing.
Ranked by richness
Top 10 Fish Highest In Omega-3
Below is each fish with its typical omega-3 content — grams of EPA and DHA per 100g. These are approximate values that vary with season, diet and whether a fish is wild or farmed, but they show clearly which fish deliver the most.
Sardines
Small, oily and brilliantly rich in omega-3 — and low in mercury as a small fish. Superb grilled or mashed onto toast, and outstanding value for the nutrition.
Order fresh sardines →Mackerel İstavrit
One of the richest omega-3 sources of any fish — a genuine nutritional powerhouse. Full-flavoured, affordable and wonderful baked or grilled.
Order fresh horse mackerel →Salmon Somon
A firm favourite for good reason: exceptionally high in omega-3 DHA, plus vitamin D and protein, with a mild flavour almost everyone loves.
Order fresh salmon →Anchovies Hamsi
Tiny but mighty — fresh anchovies are packed with omega-3 and flavour, and low in mercury. A cornerstone of the Turkish and Mediterranean table.
Order fresh anchovies →Sea Bass Levrek
A leaner fish than the oily stars, but still a worthwhile omega-3 contributor — and a delicate, versatile favourite for everyday cooking.
Order fresh sea bass →Sea Bream Çipura
Gently sweet and moderately oily, bream adds omega-3 alongside quality protein and minerals — a lovely all-rounder.
Order fresh sea bream →Turbot Kalkan
A prized, lean flatfish — lower in omega-3 than the oily fish, but a luxurious, protein-rich choice that still contributes to your weekly intake.
Order fresh turbot →Atlantic Bonito Palamut
A member of the tuna family with meaty flesh and a healthy dose of omega-3 — superb grilled in steaks and a seasonal Turkish favourite.
Order fresh bonito →Herring
One of the great oily fish — exceptionally rich in omega-3, sustainable and full of flavour. A classic that deserves a place on more plates.
Browse the shop →Trout
A gentle, salmon-like oily fish that’s rich in omega-3 and easy to love — mild, tender and family-friendly.
Browse the shop →The oily fish at the top — mackerel, salmon, herring, sardines and anchovies — are the omega-3 champions. Explore them all in the online fish shop, or learn to pick the freshest with our guide on how to choose fresh fish.
Does it make a difference?
Fresh vs Frozen
Good news for omega-3: it survives storage well. Both fresh and properly frozen fish retain their healthy fats.
Fresh
Genuinely fresh fish, eaten within a day or two, offers the finest flavour and texture along with its full omega-3 content. With a short, fast supply chain — market to door in the same week — fresh oily fish is hard to beat, and it’s exactly what we deliver.
Frozen
Omega-3 is fairly stable, so fish frozen quickly locks in its nutrients well and remains a genuinely good source. Frozen fish is convenient and reduces waste. The bigger factor for keeping omega-3 intact is how gently you cook it — not whether it was fresh or frozen.
A common question
Wild vs Farmed
Both are excellent omega-3 sources, and the “best” answer isn’t always what you’d expect.
Farmed
Farmed oily fish like salmon is often slightly higher in total omega-3 than wild, because its feed is formulated to be rich in these fats. It’s also consistent, available year-round and excellent value — a reliably nutritious choice.
Wild
Wild fish feed naturally and can have a different nutrient balance, with a leaner, firmer character and often a deeper flavour. It’s seasonal and usually pricier.
The honest answer: for omega-3, you can’t go wrong — choose the freshest, best-handled fish available, wild or farmed.
Keep the goodness in
How To Cook Without Losing Omega-3
Omega-3 is reasonably robust, but a few gentle habits help you keep the most of it — and they happen to make the best-tasting fish, too.
Bake, steam or poach
Gentle, moderate-heat methods preserve the most omega-3. Baking, steaming and poaching are ideal — and they keep oily fish beautifully moist.
Grill smart
Grilling and barbecuing are wonderful for oily fish; just avoid charring to a crisp over fierce heat for too long, which can reduce the delicate fats.
Cook on the bone
Cooking whole fish on the bone helps retain moisture and the good fats within the flesh — another reason whole fish is such a rewarding way to eat.
Don’t over-fry
Very high-heat deep-frying is the least kind to omega-3. If you love fried fish, a light pan-fry in a little good oil is gentler than a hard deep-fry.
Good to know
Frequently Asked Questions
Oily fish are highest, with mackerel among the very richest (around 2.5–2.9g per 100g), followed closely by salmon and herring, then sardines, anchovies and trout. Leaner fish like sea bass, sea bream and turbot contain less but still contribute.
General guidance recommends around two portions of fish a week, at least one of them oily, which comfortably provides the omega-3 most people need. Your exact needs vary, so follow NHS advice or speak to a health professional.
EPA and DHA are the two main long-chain omega-3 fatty acids in fish. DHA is a key structural fat in the brain and eyes, while EPA is particularly associated with supporting heart health and the body’s inflammatory balance. Oily fish provides both.
Both retain omega-3 well. Fish frozen quickly locks in its nutrients, and fresh fish that’s eaten soon is excellent too — omega-3 is fairly stable in storage. Freshness and how you cook it matter more than fresh versus frozen.
Gentle cooking preserves most of it. Baking, steaming and poaching retain the most omega-3, while very high-heat frying can reduce it a little. Cooking whole fish on the bone also helps keep the good fats in.
It varies. Farmed salmon is often slightly higher in total omega-3 than wild because of its diet, while wild fish can have a different balance. Both are excellent sources — the key is choosing genuinely fresh, well-handled fish.
For most people, yes — eating oily fish a couple of times a week provides plenty of omega-3 in a natural, well-absorbed form, alongside protein, vitamin D and minerals you don’t get from a capsule.
Small oily fish are lowest — sardines, anchovies and mackerel are rich in omega-3 while remaining low in mercury, making them some of the best all-round choices.
Yes — the DHA in oily fish supports a baby’s brain and eye development. Current guidance suggests up to two portions of oily fish a week in pregnancy, avoiding shark, swordfish and marlin and limiting tuna. Follow NHS advice and your midwife’s guidance.
House O Fish hand-selects oily fish like salmon, sardines, mackerel and anchovies at Billingsgate Market and delivers fresh across London. Order simply through our WhatsApp group and we’ll prepare your fish to order.
Why Buy From House O Fish
The omega-3 in fish is only as good as the fish itself. We’re a family-run fishmonger who hand-selects every fish at Billingsgate Market before dawn, checks it individually for freshness, and prepares it to order — so the oily fish that reaches you is genuinely fresh and at its nutritional best.
We specialise in exactly the omega-3-rich fish worth eating: salmon, sardines, mackerel, anchovies, bonito and more. Ordering is personal and simple through our WhatsApp community, with fresh delivery across London each week. Learn more about us, read about Billingsgate fish delivery and fresh fish delivery London, or get in touch.
The best of the oily fish
Hand-selected, market-fresh and prepared to order — the omega-3 champions, delivered.
Eat well, this week
Order Fresh Omega-3-Rich Fish Today
Give your body the good fats it’s designed to run on — genuinely fresh oily fish, hand-selected at Billingsgate and delivered across London. Join our WhatsApp community to see this week’s catch and order in a couple of messages.
Richest in omega-3: Mackerel · Salmon · Sardines · Anchovies · Bonito · explore the Online Fish Shop