Omega-3 is an essential fatty acid: essential because the body cannot make it by itself and therefore we must get it from food. Omega-3 comprises ‘good’ fats as they are polyunsaturated, and the three most important types are EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid) and ALA (alpha-linolenic acid). EPA and DHA mainly come from animal foods, predominantly oily fish and algae, whereas ALA is mostly found in plants.


It’s worth bearing in mind, that while omega-3 can be found in plant foods, the conversion from ALA into EPA and DHA is not as effective as those from animal products and so may be somewhat lacking for those following a vegetarian or vegan diet.

How much omega-3 should we eat?

The NHS currently has no Recommended Daily Allowance (RDA) for omega-3 but advises us to eat one portion of oily fish (about 140g) per week. Other health bodies in the UK have varying recommendations including the British Nutrition Foundation which advises two to three portions of oily fish per week which would be 1.5 g of EPA and DHA, and the British Dietetic Association is similar to the NHS with one portion of oily fish per week which is around 450mg EPA and DHA.

What are the health benefits of omega-3?

These include offering neuroprotective benefits in infants and also in adults. Studies have linked omega-3 with benefits in the treatment of depression, as well as some benefits as an anti-inflammatory in chronic conditions including diabetes and heart disease. Always see your GP or healthcare provider if you're concerned about any existing health issues before making changes to your diet.

A note on mercury in fish

Some oily fish can contain low levels of certain pollutants, including mercury, which have the potential to build up in the body if too much is consumed. This is why the NHS advise maximum recommendations for consumption of certain fish including shark, swordfish and marlin. Visit the NHS website for more information.

Top 10 omega-3 rich foods

1. Mackerel – 4.9g per fillet (90g) or 5.5g per 100g

A small, fatty fish which can be eaten fresh or smoked and added to a number of dishes including risotto, fishcakes and pasta. One mackerel fillet is about 90g so will provide around 5g of omega-3.

Try our favourite mackerel recipes.

2. Salmon – 4.8g per fillet (120g) or 4g per 100g fresh salmon

Whether it’s wild, farmed, fresh or canned, salmon is a convenient source of omega-3. It can be roasted or poached, and any number of accompaniments can be used to add flavour including chilli, soy, lemon, herbs and Hollandaise sauce. Tinned salmon can be used in sandwich fillings or in fish cakes. Fresh salmon provides more omega-3, with about 4g per 100g, compared to canned salmon which has about 1.3g per 100g.

Read more about the health benefits of salmon and try our healthy salmon recipes.

3. Cod liver oil – 24.4g per 100g

One tablespoon of cod liver oil (14g) provides 1.7g of omega-3, making it a concentrated source of this essential fatty acid. However, it is always preferable to get nutrients from foods rather than supplements – so try adding oily fish to your diet first. If this isn't possible and your GP or doctor has agreed that it is safe for you to take, the British Dietetic Association recommends looking for a supplement that contains around 450mg EPA and DHA per daily dose – the daily equivalent of eating one to two portions of oily fish per week. Most cod liver oil capsules also contain vitamin D and A, so make sure that you're not taking any other supplements such as a multivitamin, or you may exceed the recommended amounts each day. The NHS advises against taking cod liver oil during pregnancy as it contains too much vitamin A, which can be harmful to a developing baby.

Read more about the health benefits and risks of cod liver oil.

4. Kippers – 5.2g per fillet (160g) or 3.3g per 100g

Kippers are smoked herring and they contain a huge 5.2g of omega-3 per 160g fillet. A lot of people tend to have kippers for breakfast, but they can also be used to make paté or fish cakes.

Try this recipe for spiced rice with kippers & poached eggs.

5. Sardines – 2.7g per tin (90g) or 3g per 100g

Sardines are small oily fish that pack a real flavour punch. The easiest way to buy sardines is in a can, with just one can providing around 2.7g of omega-3. Sardines are great on toast for breakfast or lunch, added to salad or used as part of a pasta dish.

Try more tasty sardine recipe ideas.

6. Trout – 2.2g per fillet (130g) or 1.7g per 100g

Trout is part of the salmon family and, like its cousin, it's also a good source of omega-3 with over 2g per fillet. It can be baked, grilled, stuffed, added to salads and risottos and used as the base for a fish pâté.

Discover more ways to cook trout.

7. Sea bass – 2.1g per fillet (125g) or 1.7g per 100g

Sea bass is a meatier, stronger flavoured fish often used in Asian cooking. It contains over 2g of omega-3 per fillet and works with a variety of different flavour combinations, herbs and spices.

Discover our best sea bass recipes.

8. Flaxseeds – 2.5g of ALA per tablespoon (10g whole seeds) or 25g per 100g of ALA

This is a plant-based source of omega-3 that will convert into ALA, with just one tablespoon of whole seeds providing 2.5g of ALA. Flaxseeds are small yellow-brown seeds, a bit like sesame seeds, that can be eaten whole or ground. Add them to porridge, smoothies and soups, in energy balls or use flaxseed oil as a dressing - it's even higher in ALA.

Try flaxseeds in these energy bites or a green smoothie.

9. Chia seeds – 2.5g per tablespoon (14g) or 17.5g per 100g

Another plant-based source of omega-3, but one of the highest, chia seeds can be used as a great non-grain alternative to breakfast when soaked overnight in milk or yogurt, added to smoothies or used to make a nutritious dessert. Just one tablespoon packs over 2g of omega-3 (the ALA variety) making it a better vegan source of this all important essential fat.

Make the most of chia seeds with our recipe collection.

10. Walnuts – 2.2g per small handful (30g serving) or 7.5g per 100g

Walnuts are the super nut of omega-3 and can easily be used as a snack, in bread, baking, sprinkled onto breakfast or salads. Just one 30g serving will provide 2.2g of omega-3 (which will then be converted into ALA as it is a plant-based source). Walnut oil which can be used a salad dressing, is also a good plant source of omega-3.

Learn more about the health benefits of walnuts.

Read more

The health benefits of cod liver oil
How to eat for great skin – dietary fats
The health benefits of salmon

This article was published on 25 April 2019.

Nicola Shubrook is a qualified nutritionist registered with the British Association for Nutrition and Lifestyle Medicine (BANT) and the Complementary & Natural Healthcare Council (CNHC). Find out more at

All health content on is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other healthcare professional. If you have any concerns about your general health, you should contact your local healthcare provider. See our website terms and conditions for more information.


Nutrition data from McCance and Widdowson’s Composition of Foods unless otherwise stated.

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