What are essential fatty acids? Omegas 3 and 6

What are essential fatty acids? Omegas 3 and 6

Team ErbologyErbology

If you’ve been doing your research on how to maintain a healthy diet, you’ll almost certainly have come across the term ‘essential fatty acids’. They crop up everywhere, but it’s not always clear exactly how these mysterious molecules play a role in keeping you well. With an eye on the science, we tackle the key questions: what are essential fatty acids, and what do they have to do with the omegas?

April 27, 2022 4:44 pm

What are essential fatty acids?

There are a couple of things to know about essential fatty acids.

Let’s start at the beginning: fatty acids are molecules which join together to become fats. You can think of them as building blocks; every type of fat in our body (for example, in our cell membranes, or the natural oils produced to protect your hair and skin) is made up of fatty acids.

There are a few different types, such as saturated, monounsaturated and polyunsaturated fatty acids.

The difference between them lies in their molecular structure. (In a nutshell, unsaturated fatty acids have a double carbon bond which they can break to form an extra bond with a hydrogen atom, whereas saturated fatty acids are already full, or ‘saturated’).

But there’s also a difference in the way our bodies use them, and whether the scientific community considers them to be healthy or not.

Check out our article on good fats and bad fats for more information on each type.

But, back to our essential fatty acids. Why are they ‘essential’? Well, there are a couple of types of polyunsaturated fatty acids (PUFAs) which we can’t make ourselves, but we still need them to be able to perform key processes in our bodies. As a result, it’s ‘essential’ that we source these from our diet.


cauliflower steaks ingredients

Enter: the omegas

Polyunsaturated fatty acids can be divided into two families, which are known as omega-3 and omega-6. You might also see them written as ω-3 and ω-6; this version simply uses the Greek letter ‘omega’ to stand in for the word.

Why are they called omegas? Well, this may be science overload for some of us, but for the more chemistry-minded: the term ‘omega’ lets you know where the double carbon bond is in the molecule.

In omega-3 fatty acids, the double bond is three carbons away from one side (the methyl end) of the fatty acid chain. In omega-6 fatty acids, it’s six carbons from the end.

Anyone else getting a headache?

The good news is that you don’t really need to understand the chemical structure of fatty acids to learn how they can be beneficial for your health.

We’ve included this info here as lots of articles about essential fatty acids are chock full of mysterious jargon, and we take a belts-and-braces approach to giving you all the information in one place. Take what you need; if you’re getting high school chemistry flashbacks, it’s time to move on.

What does omega-3 do?

Omega-3 (or more accurately omega-3 fatty acids) is good for your heart.

A review of studies on omega-3 found that it had a beneficial effect on irregular heartbeat (arrhythmia), fatty deposits in blood vessels (atherosclerosis), inflammation, and internal blood clots (thrombosis).

It may also help lower blood pressure.(1)

As a result, many doctors treat patients at risk of heart disease by encouraging them to increase their intake of omega-3.

Historically, humans typically got plenty of omega-3. However in the last 100 years – perhaps thanks to the rise of processed foods – the amount of omega-3 we eat has plummeted by 80%.(1)

Generally speaking, it’s a good idea for almost everyone to keep an eye on their omega-3 intake and do their best to increase it.


Types of omega-3 to know about

As mentioned above, the term ‘omega-3’ covers a family of fatty acids. Within this, there are a few types.

There are three main types of omega-3 fatty acids(2):

Alpha-linoleic acid (ALA)

ALA is most commonly found in linseeds, chia seeds and walnuts, but you can also find it in hemp oil. It is very delicate and can be destroyed by light, oxygen and heat. This is why our hemp oil comes in an amber glass bottle, which helps keep light out, and must be stored in a dark place with the lid firmly on.

ALA is not active in the body, but your body can convert it into EPA and DHA (below), which are.

Eicosapentaenoic acid (EPA)

When looking into omega-3, you’re likely to come across lots of information recommending fish as a source. This is because fish, and fish oil, is a great source of EPA.

Docosahexaenoic acid (DHA)

Similarly, DHA is found in fish oil. This one is responsible for the association between omega-3 and brain health. A surprisingly large proportion of your brain (65%) is made up of fat, and of this, half is DHA. It’s also found in your retinas. Now, you can see why you need it!


mediterranean salad

No plant-based sources of EPA or DHA?

The good news is that your body can convert ALA from plant sources into both EPA and DHA.

The bad news is that it’s pretty inefficient at doing it. Scientists suspect that around 5% of ALA is converted into EPA by our bodies, and only around 0.5% into DHA.

So, how are vegans to get their omega-3s? Well, the good news is that many plant sources are abundant in ALA, meaning that you don’t need to down a litre of hemp oil to meet your targets.

According to the Vegan Society, in order to meet the recommended intake suggested by the Food and Agriculture Association (United Nations) and the European Food Safety Authority, you’d need to eat a tablespoon of chia seeds, or two tablespoons of hemp seeds, or six walnut halves every day.

That sounds pretty manageable, right?


organic walnuts

How do I make sure I’m getting enough ALA if I’m vegan?

However it’s important to note that the Vegan Society acknowledges that people who are following a vegan diet might need to increase their intake, citing some experts who recommend doubling it to allow for the poor rate of conversion of ALA.

That means you’d need to eat, for example, both your tablespoon of chia seeds and six walnut halves every day.

So, whack a tablespoon of chia into your smoothie first thing, and snack on some walnuts mid-afternoon, and you’ll be easily covering your bases.

Alternatively, if you want to take a less rigid approach, just try to incorporate more ALA-rich foods into your diet generally. For example, switch your main cooking oil to rapeseed oil, or start drizzling walnut oil on your porridge in the morning.

It’s also possible to get EPA and DHA from supplements made from microalgae. Generally, we always advise you to get all your nutrients from your diet, as this way you can’t overdo it and you get a great balance of combined micronutrients.

However, the Vegan Society notes that children and pregnant or breastfeeding women might benefit from looking into this, as DHA is so important in brain development. This is in line with FAO guidelines, however the importance of omega-3 supplementation during infancy or breastfeeding is disputed within the scientific community.(5)

Related reading


Olive oil

"Historically, humans typically got plenty of omega-3. However in the last 100 years - perhaps thanks to the rise of processed foods - the amount of omega-3 we eat has plummeted by 80%.(1)"

What does omega-6 do?

The other family of essential fatty acids are omega-6 fatty acids.

While pretty much everyone agrees that omega-3 fatty acids are good for you, there is more debate over omega-6.

For example, some research has linked high intake of omega-6 (relative to omega-3) to inflammation, which in turn can lead to cardiovascular disease, nonalcoholic fatty liver disease, inflammatory bowel disease and even Alzheimer’s.(6)

However other research disputes this, and even claims that omega-6 is linked with lower rates of cardiovascular disease.(7)

When researching omega-6, you’ll almost always find it in tandem with omega-3. This is because the two interact in your body (more on that below), so many scientists have begun to talk about judging their healthiness in terms of their ratio to one another.

Types of omega-6 to know about

Just like omega-3, omega-6 can be divided down into a few different types as follows.

Linoleic acid (LA)

This is the most common of the omega-6 fatty acids and is found in vegetable oils, nuts and seeds. This is the type you’re probably eating the most of, along with ARA.

Arachidonic acid (ARA)

ARA is found in meat, poultry and fish, but the body can also convert some linoleic acid into ARA. However, similarly to what we saw with the omega-3s, our bodies are not terribly efficient at doing this and the amount of ARA produced from linoleic acid is relatively small.(8)

ARA plays a role in inflammation, although the debate continues as to whether, on its own, it’s beneficial to our health or not.

Gamma linoleic acid (GLA)

GLA appears in evening primrose oil and blackcurrant seed oil. Curiously, this one seems to act as an anti-inflammatory.(9) Not too many of us regularly eat the seed oils which naturally contain GLA, so it’s one of the less common omega-6 fatty acids you’re likely to come across in a normal diet.

Conjugated linoleic acid (CLA)

CLA is found in meat and milk and is a natural trans fat. If you’ve read our article on good fats and bad fats, the very phrase ‘trans fat’ will have you running for the hills. However, CLA is very different from harmful industrial trans fat, and is actually thought to be quite good for you.

For example, going against the conventional wisdom that ‘eating fat makes you fat’, CLA has actually been linked to weight loss.(10)


hemp seed oil toast

The perfect ratio of omega-6 to omega-3

As hinted above, many scientists have come to the conclusion that the healthiest way to consume essential fatty acids is to get the right balance between the two families.

While different researchers cite different figures, the estimates coalesce around a ratio of between 1:1 and 4:1 (omega-6:omega-3).

While a long time ago this would have been easy to achieve, changes in our diets over the last hundred years have radically changed the ratio of omegas – and not in a good way. In fact, we’re now likely to be eating these fats in a ratio of between 15 and 20:1.(6)

The evidence is pretty clear: we’re getting too many omega-6 fatty acids and not enough omega-3s. Too much omega-6 in your system may kick off the inflammatory response, which some scientists think may exacerbate inflammatory illnesses such as cardiovascular disease, diabetes and rheumatoid arthritis.(6)

So, how to remedy this and keep your diet as healthy as possible?

How can I get the right ratio?

There is still some debate in the scientific community about whether you should get to the right ratio of omegas by increasing your omega-3 intake, or decreasing your omega-6 intake.

Some point out that PUFAs can be turned quite easily into free radicals within the body. Remember that double bond which makes them so special? Turns out it can also be used to turn it into a potentially damaging free radical, which can go on to cause cell damage.(11)

This happens during a chain reaction called lipid peroxidation. The logic goes that if there aren’t enough lipids to perpetuate the chain, then less damage will be caused.

That’s a good argument for watching your overall intake and not eating an excessive amount of PUFAs.

However others have argued that as long as the ratio is right, we might actually be better off getting to the right ratio by increasing our intake of omega-3s.

Advocates include the American Heart Association, which argues that omega-6 fatty acids aren’t bad for your cardiovascular health. Instead, they claim, we should focus on getting our omega-3s up to the right level.(12)

Getting the essential fatty acids right in your diet

While we won’t claim to have a conclusion where scientists haven’t yet found one, we do think there’s some common sense advice that will help you manage omegas in your diet.

Firstly, if you follow a Western diet, you will almost certainly be getting enough omega-6, so no need to worry about consuming more of it.

However, you’re probably not getting it from the right place. Much of our omega-6 comes from processed vegetable oils used in cooking (such as refined sunflower oil).

The trouble is, these oils are heavily processed. Not only does this remove lots of good nutrients, it leaves them very prone to oxidation when exposed to air and heat during cooking. Scientists have raised concerns about the health risks of consuming oxidised lipids.(13)(14)

Much better to source the omega-6 you need from cold-pressed oils such as hemp seed oil. Not only does it contain a wealth of other vitamins, such as omega-3 and vitamins D and E, it’s less prone to oxidation.

The lowdown on the omegas

When it comes to whether you should consume less, the jury is still out. However it’s worth noting that we get a lot of our omega-6 from vegetable oils, which are prevalent in processed foods. We know that eating a lot of processed food is bad for us, so it makes perfect sense to swap some of those out and replace them with healthy whole foods.

It’s good advice in general, and it’ll also bring your omega ratio closer to where it needs to be.

This is especially true for vegans, who may have a harder time bringing their levels of omega-3 up when compared to their meat and dairy-eating pals.

We also know that most of us aren’t getting enough omega-3, and the science is pretty clear: it’s good for you. So, add a couple of portions of fatty fish to your diet each week, or make sure you remember to add that tablespoon of chia seeds to your breakfast bowl.

We can let the scientists figure out any open questions, but in the meantime we can rest assured we’re moving towards that perfect ratio of omegas.

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