Omega-3 fatty acids are essential fats that support heart health, brain function, vision and normal inflammatory balance. ¹ Because the body cannot produce enough omega-3 on its own, it must come from food or supplements.
While omega-3 supplements remain popular, many people first search for ways to increase omega-3 naturally through diet. The challenge is that most Western diets are relatively low in oily fish and other rich omega-3 sources, meaning intake often falls below recommended levels. ²
This guide explores the best foods high in omega-3, the difference between plant and marine sources, and when supplements may still be useful.
What Are Omega-3 Fatty Acids?
Omega-3s are a group of polyunsaturated fats involved in several important functions throughout the body.
The three main types are:
|
Omega-3 Type |
Found In |
Main Role |
|
EPA (eicosapentaenoic acid) |
Oily fish, fish oil |
Heart and inflammatory support |
|
DHA (docosahexaenoic acid) |
Oily fish, algae |
Brain, eyes and nervous system |
|
ALA (alpha-linolenic acid) |
Nuts and seeds |
Plant-based omega-3 source |
EPA and DHA are considered the most biologically active forms because the body can use them directly. ³
ALA, found in plant foods, can be converted into EPA and DHA, but the conversion rate is relatively low.
Why Omega-3 Matters
Omega-3 fatty acids contribute to several important areas of health.
Research has explored omega-3 intake in relation to:
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Heart and cardiovascular wellbeing
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Brain and cognitive function
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Eye health
-
Joint comfort and mobility
-
Healthy ageing ¹
DHA is particularly important for the brain and retina, while EPA is often associated with inflammatory balance and cardiovascular support.
The Best Foods High in Omega-3
Oily Fish: The Richest Natural Source
Oily fish are by far the best dietary source of EPA and DHA.
The highest omega-3 fish include:
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Salmon
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Mackerel
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Sardines
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Herring
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Anchovies
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Trout
These fish provide direct EPA and DHA, making them more effective sources than plant-based omega-3 foods.
The NHS recommends eating at least one portion of oily fish per week as part of a balanced diet. ⁴
Salmon and Omega-3
Salmon is one of the most popular omega-3-rich foods due to its high DHA and EPA content and versatility in meals.
Wild salmon generally contains slightly higher omega-3 levels than farmed salmon, although both remain good sources.
Salmon also provides:
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Protein
-
Vitamin D
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Selenium
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B vitamins
This combination makes it one of the most nutrient-dense foods for overall wellbeing.
Sardines and Mackerel: Affordable Omega-3 Sources
Sardines and mackerel are often overlooked despite being among the richest omega-3 foods available.
They are also:
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Relatively inexpensive
-
Widely available
-
Naturally high in vitamin D and calcium
Because they are smaller fish, sardines are often considered lower in environmental contaminants compared with larger predatory fish.
Plant-Based Foods High in Omega-3
Plant foods mainly provide ALA omega-3 rather than EPA and DHA.
Some of the best plant-based omega-3 foods include:
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Flaxseeds
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Chia seeds
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Walnuts
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Hemp seeds
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Rapeseed oil
These foods can help increase overall omega-3 intake, particularly for vegetarians and vegans.
However, because ALA conversion into EPA and DHA is limited, some people choose algae-based omega-3 supplements instead. ⁵
Chia Seeds and Flaxseeds
Chia and flaxseeds are especially popular in smoothies, oats and yoghurt bowls.
Flaxseeds are richest in ALA when ground rather than eaten whole, as this improves digestion and absorption.
Both are also good sources of fibre, making them beneficial additions to a balanced diet beyond omega-3 alone.
Eggs and Fortified Foods
Some eggs, yoghurts and dairy alternatives are fortified with omega-3.
These products may help increase intake slightly, although they generally contain much lower levels than oily fish or concentrated supplements.
Fortified foods can still be useful for people who rarely consume seafood.
Can You Get Enough Omega-3 from Food Alone?
In theory, yes, but in practice, many people struggle to consume enough oily fish consistently.
Modern diets often contain:
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High amounts of processed foods
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Too much omega-6 fat relative to omega-3
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Limited seafood intake
This imbalance is one reason omega-3 supplements remain so widely used.
People who may find supplementation helpful include:
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Those who rarely eat fish
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Vegetarians and vegans
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Older adults
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People focused on heart or brain health support
Omega-3 Supplements vs Food
Whole foods should always form the foundation of nutrition, but supplements can help bridge dietary gaps.
Fish oil supplements provide concentrated EPA and DHA without needing to consume oily fish multiple times weekly.
Common omega-3 supplement forms include:
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Fish oil capsules
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Cod liver oil
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Krill oil
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Algae-based omega-3
When choosing a supplement, it’s important to check the actual EPA and DHA content rather than just total fish oil amount.
How Much Omega-3 Do You Need?
Most health organisations recommend around 250–500 mg combined EPA and DHA daily for general adult health. ¹
People with specific dietary goals may consume more, although requirements vary depending on lifestyle and overall diet.
Regular intake matters more than occasional high doses.
Choosing the Best Omega-3 Foods
A balanced omega-3-focused diet usually includes a combination of:
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Oily fish
-
Plant-based omega-3 foods
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Whole, minimally processed meals
For those who do not regularly consume oily fish, supplements may provide a practical alternative.
Consistency is key, as omega-3 levels build gradually within the body over time.
Increasing Omega-3 Naturally
Omega-3 fats play an essential role in heart, brain and joint health, yet many people still do not consume enough through diet alone.
Adding more oily fish, seeds, nuts and fortified foods can help improve intake naturally. For people who struggle to eat enough omega-3-rich foods consistently, high-quality supplements may also help support long-term wellbeing.
Whether through food, supplements or a combination of both, increasing omega-3 intake remains one of the simplest nutritional changes you can make for overall health.
