What Are Essential Fatty Acids? Sources & Why We Need Them

Fat often gets talked about as something we should eat less of, but fats are an important part of a balanced diet. They provide energy, help the body absorb the fat-soluble vitamins A, D, E and K, and perform a variety of functions throughout the body.

Among them are two nutrients known as essential fatty acids. Unlike some other fatty acids, our bodies cannot make these themselves, which means we need to obtain them through our diet.

So, what are essential fatty acids, which foods contain them, and how do they relate to Omega 3 and Omega 6?

What Are Essential Fatty Acids?

Essential fatty acids are polyunsaturated fatty acids that the body needs but cannot produce itself.

There are two essential fatty acids:

• Alpha-linolenic acid (ALA) – an Omega 3 fatty acid

• Linoleic acid (LA) – an Omega 6 fatty acid

Because our bodies can't make ALA or LA, they need to come from food.

This is also why you'll often hear Omega 3 and Omega 6 described as “essential fats”. More precisely, however, it is ALA from the Omega 3 family and linoleic acid from the Omega 6 family that are essential fatty acids.

Why Do We Need Essential Fatty Acids?

Fats have several important roles within a healthy diet. Essential fatty acids form part of this wider picture, while individual fatty acids have different functions in the body.

For example, linoleic acid contributes to the maintenance of normal blood cholesterol levels when consumed at the required level, while ALA contributes to the maintenance of normal blood cholesterol levels with a daily intake of 2g.

ALA can also be converted by the body into the longer-chain Omega 3 fatty acids EPA and DHA, although this conversion is limited.

EPA and DHA have their own recognised roles. EPA and DHA contribute to the normal function of the heart with a daily intake of 250mg EPA and DHA, while DHA contributes to the maintenance of normal brain function and normal vision with a daily intake of 250mg DHA.

What Foods Contain Essential Fatty Acids?

The best place to start is your diet. Essential fatty acids occur naturally in a variety of everyday foods.

Sources of Omega 3 ALA

Plant sources of ALA include:

• Flaxseeds and flaxseed oil

• Chia seeds

• Walnuts

• Rapeseed oil

• Hemp seeds and hempseed oil

Oily fish is also an important part of the Omega 3 conversation, although fish predominantly provides the longer-chain Omega 3 fatty acids EPA and DHA rather than being a major source of ALA.

Sources of Omega 6 Linoleic Acid

Linoleic acid is widely available in the diet and can be found in foods including:

• Nuts

• Seeds

• Sunflower oil

• Safflower oil

• Soya bean oil

• Other commonly used plant oils

For many people eating a varied diet, obtaining Omega 6 isn't particularly difficult because it is present in a wide range of foods.

Essential Fatty Acids vs Omega 3: What's the Difference?

The terminology can get confusing because “essential fatty acids” and “Omega 3” are sometimes used as though they mean the same thing. They don't.

ALA is an essential Omega 3 fatty acid. EPA and DHA are also Omega 3 fatty acids, but aren't generally classified as essential in the same way because the body can produce small amounts from ALA. Likewise, linoleic acid is an essential Omega 6 fatty acid.

Omega 7 and Omega 9 aren't essential fatty acids because the body is able to produce them. If you'd like to understand how the different omega families compare, read our guide to Omega 3, 6, 7 and 9.

What About Fish Oil?

Fish oil is a source of the long-chain Omega 3 fatty acids EPA and DHA. Oily fish such as salmon, sardines, mackerel and herring can provide EPA and DHA through the diet. For people who don't regularly eat oily fish, Omega 3 supplements are another way of obtaining EPA and DHA.

When comparing fish oil supplements, look at the amount of EPA and DHA per recommended daily serving, rather than judging a product solely by the total amount of fish oil.

Explore our Omega 3 supplements and fish oils to compare different options.

Can You Get Omega 3 Without Eating Fish?

Yes. There are several plant-based sources of Omega 3. Flaxseed, chia seeds, walnuts and hemp seeds provide ALA, while algae can provide DHA and, depending on the product, EPA.

This makes algae-derived Omega 3 particularly useful for people following vegan and plant-based diets who are looking for a direct source of DHA or EPA and DHA without fish oil.

Explore our Vegan Omega range for plant-based and algae-derived supplements.

Do I Need an Essential Fatty Acid Supplement?

A balanced diet containing foods such as nuts, seeds, plant oils and oily fish can provide a range of fatty acids, so supplements aren't automatically necessary.

Whether an omega supplement is appropriate will depend on your diet, dietary preferences and what you're looking to supplement.

If you're considering a supplement, first establish which type of omega it provides. An Omega 3 fish oil, an ALA-rich flaxseed oil and a blended Omega 3-6-9 supplement aren't nutritionally identical.

Our guide to Omega Oils explains the differences between Omega 3, 6, 7 and 9 and can help you understand the different options.

If you're pregnant or breastfeeding, taking medication or have a medical condition, speak to your doctor, pharmacist or another appropriately qualified healthcare professional before starting a new supplement.

Essential Fatty Acids: The Evergreen View

Fat is an important part of a balanced diet, and there's no need to fear it. The focus should be on including a variety of nutritious sources of unsaturated fats as part of your everyday diet.

For essential fatty acids, that means obtaining ALA and linoleic acid through foods such as nuts, seeds and plant oils. Oily fish can provide the long-chain Omega 3 fatty acids EPA and DHA, while algae offers a fish-free source.

If you'd like to supplement your diet, explore our Omega Oils range for Omega 3, 6, 7 and 9 supplements, including fish oil, vegan and liquid options.

Are you looking for more nutritional advice? Then read our blog 'What are the Benefits of Taking Amino Acids?'. 

Checked and updated: 22nd September 2026