What are essential fatty acids?

23/11/20225 min read

Eating oily fish is good for you, but why? it contains essential fatty acids. Discover the health benefits of ‘good’ fats, the link with omega-3 and more.

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Healthy Diet

Essential fatty acids like omega-3 really are essential for our health – but do you know why? Get the lowdown on all things omega with our guide

Written by Cheryl Freedman on February 15, 2019 Reviewed by Dr Sarah Schenker on February 27, 2019

You might know it’s important to eat some oily fish every week, and that nuts contain ‘good’ fats, but most of us would struggle to say why. One answer is that both contain essential fatty acids, or EFAs, that are vital for our health and wellbeing. It’s also important that we get the right balance of EFAs in our diets. If you’re left wondering what this all means, get the essential facts about essential fatty acids below.

What are essential fatty acids?

EFAs are fatty acids that the body cannot make or has limited capacity to make so we must get them through the foods we eat. They’re needed for the normal, healthy functioning of cells and various body processes.

There are two essential fatty acids. The first is linoleic acid (LA), also known as vitamin F, and it’s part of the omega-6 family. The second is known as alpha linolenic acid (ALA) and it’s in the omega-3 family.

Two other omega-3 acids are considered semi-essential as the body can make them – but our capacity to do this is limited. These are: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).¹ These are all polyunsaturated acids, known as PUFAs.²

Why do we need EFAs?

The essential fatty acids are needed so that they can be converted into other omega-3 and omega-6 fatty acids, which are vital components of cell membranes – so every tissue in our body needs them to work properly.³Omega-3s have lots of additional benefits,⁴ such as:

helping to regulate blood cholesterol levels
supporting heart health
growth and development in unborn babies

On-going research into omega-3 has also found it can help reduce blood pressure (even in young, healthy adults),⁵ maintain healthy brain function as we age,⁶ and may be beneficial for dry skin conditions such as eczema.⁷ There’s even evidence that omega-3 could ease symptoms of depression.⁸ Omega-6 fatty acids are also important for health, and LA in particular has been linked with:⁹

keeping cholesterol levels stable
aiding weight loss, as part of a meal-replacement plan
supporting skin and hair health

Which foods contain essential fatty acids?

ALA (alpha-linolenic acid) – found in vegetable oils, flaxseeds, nuts including walnuts, soybeans and green leafy veggies
EPA (eicosapentaenoic acid) – oily fish such as salmon or mackerel, shellfish including crab, and marine algae
DHA (docosahexaenoic acid) – as EPA¹⁰

Our body can make a small amount EPA and DHA from ALA, but it cannot produce ALA.¹¹However, it’s a good idea to get all your omega-3s from your diet as the body’s conversion of ALA is limited. There are several kinds of omega-6 fatty acids, including:^12-14

linoleic acid – the most common type of omega-6, found in vegetable oils such as rapeseed and sunflower, and some nuts
gamma-linoleic acid – found mainly in vegetable oils, including evening primrose oil
conjugated linoleic acid – rich sources include animal protein and dairy products

How many EFAs do I need?

There's no set reference nutrient intake (RNI) for either omega-3 or omega-6. If you eat fish, the government recommends two portions of approximately 140g each a week, one of which should be oily fish. This will give you around the same amount of combined EPA and DHA (450mg) as you’d find in a fish oil supplement.¹⁵

Be aware that many of us are eating too much omega-6 in relation to omega-3. This is partly thanks to processed foods containing refined oils like corn or palm oil – think cakes, biscuits and margarine.

The ideal ratio is thought to be 4:1 omega-6 to omega-3, but we’re eating closer to 15:1!¹⁶An imbalance of omega-6 in the diet has been linked to inflammatory conditions such as arthritis, Alzheimer’s and heart disease.¹⁷

A 2016 study published in the journal Nutrients also found that too much omega-6 could also up your risk of obesity.¹⁸

So, should I cut out omega-6?

Not so fast – the debate over omega-6 continues. For example, a 2017 study by the University of Eastern Finland found omega-6 is not as inflammatory as previously thought, while a 2018 study by the same team examined data from 2500 men taken over 20 years and discovered higher levels of omega-6 were actually linked to a lower risk of fatal cardiovascular disease.^19,20

While the evidence is still evolving, it’s important to make sure you follow a healthy, nutrient-rich diet. Rather than cutting out omega-6 completely, experts suggest upping your intake of omega-3s and reducing your intake of omega-6 from processed foods to help balance out your intake of EFAs.²¹It’s as easy as 1, 2, omega-3!