Oily Fish: Health Benefits, Best Choices & How Much to Eat
By R.Davies, PhD・Nutrition
Updated April 07, 2026 | 4 min read
Oily fish are fish with higher fat content that provide long-chain omega-3 fatty acids, which support cardiovascular, brain, and metabolic health. This article explores the key health benefits of consuming these nutrient-dense fish regularly.
They include fish like salmon, trout, mackerel, sardines, herring, and anchovies, which are defined by their higher fat content compared to white fish. Specifically, it’s all about the long-chain omega-3 fatty acids. These fats are largely absent from typical Western diets and difficult to obtain in meaningful amounts from other foods.
Unlike white fish (like cod, flatfish, or tilapia), which primarily store fat in their liver, oily fish distribute fat throughout their flesh. This is why they provide a reliable and concentrated source of omega-3s in a normal portion size.
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Is fish high in omega-3?
Oily fish stand out, nutritionally, because they supply two omega-3 fatty acids: eicosapentaenoic acid ('EPA') and docosahexaenoic acid ('DHA'), which are difficult to find anywhere else in nature. While small amounts of omega-3s are found in some plant foods, these do not provide the same compounds, quantities or benefits.
Because EPA and DHA are not efficiently produced by the body and are not found in many other foods, oily fish represent one of the most efficient ways to increase intake through diet alone. Some plant foods, such as flaxseed, walnuts, and chia seeds, contain another omega-3 called alpha-linolenic acid ('ALA').
While ALA is beneficial by itself, the body converts ALA into EPA and DHA very inefficiently. As a result, relying on plant sources alone typically leads to low levels of EPA and DHA. For most people, oily fish remain the most practical dietary source of these fats.
Health Effects
EPA and DHA are incorporated into the 'cell membranes' throughout your body, where they help control inflammation, brain health and cardiovascular health [1]. This is why you need them.
Regular consumption of oily fish is associated with a lower risk of cardiovascular disease and major cardiovascular events such as heart attack and stroke, even at relatively modest intakes [2]. These benefits appear strongest in people who don't get a lot of omega-3 from their diet.
DHA is also a major (important!) structural component of your brain. It makes up a large proportion of the polyunsaturated fats found in brain tissue and plays a role in maintaining normal brain structure, brain function and brain health.
Thus, higher intakes of oily fish have been associated with better cognitive performance in older adults and a lower risk of cognitive decline, dementia, and Alzheimer’s disease [3]. Researchers believe these effects are partly due to substances derived from EPA and DHA that help protect brain cells from damage and support brain cell maintenance as you age.
Additional Benefits
In addition to omega-3s, oily fish also provide a range of other nutrients and health benefits. A typical 100g (3.5 oz) serving of oily fish can provide: 50-100% of your vitamin D, 20–25 grams (1 oz) of high-quality protein, vitamin B12, niacin and selenium.
Smaller species, such as sardines and anchovies, are often eaten with their soft, edible bones, which can also provide calcium. You won't get that from the supplements.
How Much Do You Need?
Recommendations vary slightly, but most experts suggest eating fish at least twice per week, with at least one serving being oily fish. In practical terms, this equates to 200–250 grams (7–9 ounces) of fish per week. Most oily fish provide 1.3–2.5 grams of EPA and DHA per 100 grams, meaning that even one or two servings per week can substantially increase your omega-3 intake.
How to increase your intake of fish
1. Canned Options
Fresh fish can be expensive and difficult to prepare. But canned sardines, salmon, and mackerel are affordable, shelf-stable, and ready-to-eat. For a quick snack, canned sardines in olive oil can be mashed and eaten on whole-grain crackers or toast with lemon juice and black pepper. Or they can be tossed with pasta, capers, and roasted tomatoes.
Canned salmon can be used to make fish cakes if you aren’t a massive fan of the flavour of oily fish. Mix the salmon with breadcrumbs, egg, herbs and other flavours, then pan-fry or bake until golden.
2. Keep it Simple
If you’re comfortable with fresh fish, put it on top of your favourite roast vegetables. Bake fillets of salmon, trout, or mackerel at 400°F (200°C) for 8–15 minutes (depending on how big the fillets are). Serve with a sauce made of Greek yoghurt, dill, and lemon.
To cover the flavour of oily fish, you can marinate them in olive oil, garlic, and herbs for hours before cooking.
3. Make it a Staple
Make oily fish a regular event. “Fish Friday” is a household tradition around the world. Kippers, smoked salmon, or mackerel can be eaten for breakfast at the weekend. Tinned tuna or sardines on toast can be a mid-week lunch.
Keep a rotating menu of three simple fish recipes that you've mastered and alternate between them. Consider batch-cooking: cook multiple portions at once, then use throughout the week: in salads, in tacos, wraps or sandwiches or alongside different grains and vegetables. Oily fish is delicious fridge-cold or room temperature.
Key Takeaways
Oily fish are one of the most efficient dietary sources of EPA and DHA — two nutrients that are difficult to obtain elsewhere. These nutrients, which are consistently linked to good cardiovascular and brain health. There are no other substitutes found in nature
While there are issues around access, cost, and taste, using canned fish, simple recipes, and combining oily fish with other strong complementary flavours can help you get more of them into your diet.
Sources
1. Calder PC. Omega-3 fatty acids and inflammatory processes. Nutrients. 2010 Mar;2(3):355-374. doi: 10.3390/nu2030355. Epub 2010 Mar 18. PMID: 22254027
2. Hu Y et al. Marine Omega-3 Supplementation and Cardiovascular Disease: An Updated Meta-Analysis of 13 Randomized Controlled Trials Involving 127 477 Participants. J Am Heart Assoc. 2019 Oct;8(19):e013543. PMID: 31567003
3. Godos J et al. Fish consumption, cognitive impairment and dementia: an updated dose-response meta-analysis of observational studies. Aging Clin Exp Res. 2024 Aug 20;36(1):171. PMID: 39162889
Published: December 29, 2025
Updated: April 07, 2026
Lead Author: R.Davies, PhD | Author Bio
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