Unless you’ve been living under a rock you should know, or at least have heard about, omega 3 fatty acids. If you haven’t its worth checking out our article on 5 Simple Food Choices for Long Term Health Results
Now, strap in. I’m about to lay down all the knowledge you’ll ever need on Omega 3, 6 and 9.
Let’s start at the beginning. What is a fatty acid?
If you search Google for ‘fatty acid’ you’ll be met with the following definition: ‘a fatty acid is a carboxylic acid with a long aliphatic chain, which is either saturated or unsaturated’. If you’re like most people, and not a nerd like myself, that probably made no sense. Don’t worry, I’ll translate.
“A fatty acid is a chain of carbon, oxygen and hydrogen atoms with a carboxyl group (-COOH acid) on one end. The chain can be either saturated (rigid) or unsaturated (flexible)”. We can classify fatty acids based on the number of carbon atoms, whether they can accept more atoms, how flexible they are and where the first unsaturated bond appears in the chain (if it even has one).
Omega-3 and Omega-6 fatty acids each have more than one unsaturated bond, therefore we can say they are poly-unsaturated. The numbers in Omega-3 and Omega-6 describe where the first unsaturated bond exists in the fatty acid structure; 3rd and 6th carbon atom respectively.
What are essential and non-essential fatty acids?
Essential fatty acids are those that our body needs in order to function properly, yet as human beings, we’re unable to make them ourselves. By this I mean we need to get them from our diets, we cannot synthesise them from other things we consume. Omega-3 and Omega-6 are essential fatty acids.
In contrast, non-essential fatty acids can be made by our bodies using other components from our diet. Omega-9 is a non-essential fatty acid (meaning our bodies can synthesise it) and will be discussed in a future article.
NB: Omega 3 and 6 fatty acids are also called ω-3/ω-6 or n-3/n-6 fatty acids.
What are Omega-6 Fatty Acids? What you need to know
Omega-6 is not a single compound, rather an umbrella term for many fatty acids with an ‘n-6’ structure; the type with it’s first unsaturated bond located at the 6th carbon atom. They form an important part of the diet and are essential for optimal health. Omega-6 fatty acids are found in a variety of foods, such as plant oils (like corn and soybean oil), nuts, seeds, and certain vegetables. They play an important role in cardiovascular health, inflammation and even helping to regulate blood sugar levels.
| Common name | Lipid name | Chemical name |
| Linoleic acid (LA) | 18:2 (n−6) | all-cis-9,12-octadecadienoic acid |
| Gamma-linolenic acid (GLA) | 18:3 (n−6) | all-cis-6,9,12-octadecatrienoic acid |
| Calendic acid | 18:3 (n−6) | 8E,10E,12Z-octadecatrienoic acid |
| Eicosadienoic acid | 20:2 (n−6) | all-cis-11,14-eicosadienoic acid |
| Dihomo-gamma-linolenic acid (DGLA) | 20:3 (n−6) | all-cis-8,11,14-eicosatrienoic acid |
| Arachidonic acid (AA) | 20:4 (n−6) | all-cis-5,8,11,14-eicosatetraenoic acid |
| Docosadienoic acid | 22:2 (n−6) | all-cis-13,16-docosadienoic acid |
| Adrenic acid | 22:4 (n−6) | all-cis-7,10,13,16-docosatetraenoic acid |
| Docosapentaenoic acid | 22:5 (n−6) | all-cis-4,7,10,13,16-docosapentaenoic acid |
| Tetracosatetraenoic acid | 24:4 (n−6) | all-cis-9,12,15,18-tetracosatetraenoic acid |
| Tetracosapentaenoic acid | 24:5 (n−6) | all-cis-6,9,12,15,18-tetracosapentaenoic acid |
Of these compounds, while they are all serve a purpose, the ones thought to be most important are Gamma-linolenic acid (GLA), Dihomo-gamma-linolenic acid (DGLA) and Arachidonic acid (AA).
Arachidonic acid (AA) is of particular importance because it responsible for the unfavourable inflammatory properties of the omega-6 family. You guessed it, this is the one causing all the bad press and unfortunately as you’ll later read, we’re likely getting too much of it.
Inflammation negatively affects our health and can exacerbate and even cause disease. In fact, most chronic diseases, such as cancer, diabetes, heart disease, eczema, arthritis and Alzheimer’s disease, are highly inflammatory.
On the flip side Dihomo-gamma-linolenic acid (DGLA) has an anti-inflammatory property but is hard to come by within our diets. The best way to increase DGLA is to increase its precursor Gamma-linolenic acid (GLA) which can be found in evening primrose oil, borage oil and black currant seed oil.
Before we continue it’s important to note that while we have been speaking about the different omega-6 fatty acids individually, much like the omega-3 fatty acids, they are all intrinsically linked by a series of enzymes which converts one type to another. For example DGLA can be made via the elongation of GLA thanks to the elongase enzyme. The diagram below shows the cascade of events which can convert the most simple omega-6 acid, linoleic acid (LA), into GLA then to DGLA and eventually docosapentaenoic acid.
What you need to know about Omega-3 Fatty Acids
While omega-3 fatty acids are considered to be anti-inflammatory, the reality is they’re either neutral or less inflammatory than their omega-6 counterparts. It is thought that early humans had a diet richer in omega-3 than our modern day equivalent and perhaps this explains the increasing number of chronic inflammatory conditions, although that being said our ancient ancestors didn’t live as long either.
As with omega-6 fatty acids there are many different omega-3 (or n-3) fatty acids of which the most common have been listed below:
| Common name | Lipid name | Chemical name |
| Hexadecatrienoic acid (HTA) | 16:3 (n-3) | all–cis-7,10,13-hexadecatrienoic acid |
| α-Linolenic acid (ALA) | 18:3 (n-3) | all–cis-9,12,15-octadecatrienoic acid |
| Stearidonic acid (SDA) | 18:4 (n-3) | all–cis-6,9,12,15-octadecatetraenoic acid |
| Eicosatrienoic acid (ETE) | 20:3 (n-3) | all–cis-11,14,17-eicosatrienoic acid |
| Eicosatetraenoic acid (ETA) | 20:4 (n-3) | all–cis-8,11,14,17-eicosatetraenoic acid |
| Eicosapentaenoic acid (EPA) | 20:5 (n-3) | all–cis-5,8,11,14,17-eicosapentaenoic acid |
| Heneicosapentaenoic acid (HPA) | 21:5 (n-3) | all-cis-6,9,12,15,18-heneicosapentaenoic acid |
| Docosapentaenoic acid (DPA), Clupanodonic acid | 22:5 (n-3) | all–cis-7,10,13,16,19-docosapentaenoic acid |
| Docosahexaenoic acid (DHA) | 22:6 (n-3) | all–cis-4,7,10,13,16,19-docosahexaenoic acid |
| Tetracosapentaenoic acid | 24:5 (n-3) | all–cis-9,12,15,18,21-tetracosapentaenoic acid |
| Tetracosahexaenoic acid (Nisinic acid) | 24:6 (n-3) | all–cis-6,9,12,15,18,21-tetracosahexaenoic acid |
The most important of these n-3 fatty acids are α-Linolenic acid (ALA), Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA). Though we possess the ability to convert ALA into DHA after a series of steps involving different enzymes, the process is thought to be very inefficient, less than 5%. Consequently, it is better to consume these fatty acids in the form we need through food or supplements. The diagram below shows the steps from ALA to DHA
EPA and DHA are thought to be responsible for much of the benefit of omega-3 fatty acids. Benefits include: reduced cholesterol, reduced blood pressure, antidepressant activity, visual and neurological development in infants, protective properties in Alzheimer’s disease and dementia, and so on. If you want to know more about the benefits of omega-3 we recommend you read ‘The Facts on Omega-3 Fatty Acids‘.
Omega-3 versus Omega-6 – An oily showdown
As mammals we lack the omega-3 desaturase enzyme, we cannot convert omega-6 fatty acids into omega-3 fatty acids. This means we must obtain both omega-3 and omega-6 essential fatty acids from our diet separately, there is no cross over. To make things more complicated the ratio of omega-3 to omega-6 matters because they both compete to use the same enzymes.
Early humans were thought to have a ratio of omega-3 to omega-6 of 1:1 however, that ratio has been increasing in favour of Omega-6, especially over the last century. In fact, recent estimates put the average UK diet at a ratio of 1:10. On the other hand, our American cousins have ratios as high as 1:25!
In the age of ultra processed food, perhaps the gold standard of 1:1 is no longer achievable. We can however do better than 1:10. In fact, in parts of Japan it is reported they have ratios around 1:4 due to their diets high in fish consumption.
How are they in competition with each other?
For the sharpest tools in the shed, you would have noticed that both groups use the same enzymes when converting from one form to another Consequently, they are in competition with each other to access the same limited resource, enzymes. The diagram below demonstrates this more clearly
As a consequence of the competition, the proportion of omega-3 to omega-6 in our diets is important to consider. An excess of omega-6 means more omega-6 will be processed in relation to omega-3, and thus an imbalance is created. A pro-inflammatory imbalance.
The same applies if there is an excess of omega-3 to omega-6 in our diets, however imbalance would be very unlikely. Unlikely because the number of food sources we have available to consume omega-3 fats is significantly limited when compared to the abundance of dietary Omerga-6 sources.
Is your fatty acid intake contributing to chronic Inflammation?
The best sources of omega-3 is oily fish, such as salmon, mackerel, herring and sardines, all of which provide EPA ad DHA, the specific fatty acids thought to provide the benefits of omega-3’s. Plant sources are available, for example walnuts, chia seeds, flaxseeds (and its oil) and canola oil. Plant sources of Omega-3 tend to be low in EPA and DHA, but have a greater abundance of ALA.
Remember we mentioned earlier that the conversion of ALA into EPA and DHA is not very efficient? Well, it’s for this reason vegans and vegetarians relying exclusively on these sources need to ensure they eat adequate amounts; that’s also why vegans and vegetarians are notorious for having low omega-3 levels. There is research being done as to whether vegans and vegetarians can process ALA with greater success but the results are not conclusive as of yet.
Omega-6’s on the other hand are easy to come by and used in many of your favourite processed and fast foods. Vegetable oils tend to be high in omega-6 fatty acids and include: corn, sunflower, sesame, peanut, soybean and anything called just ‘vegetable oil’. Sunflower and corn oil are the most common oils used in cooking and for this reason you are more than likely getting enough omega-6, probably too much. Over the past century our consumption of these oils has skyrocketed thanks to convenience food. With that, our ratio of omega-3 to omega-6 has moved in favour of omega-6 fatty acids. Perhaps this goes part way to explain why chronic inflammatory conditions like IBS, Crohn’s and dermatitis are on rise.
Omega-6 and Inflammation
We touched on this earlier but in case you have forgotten Arachidonic acid (AA) is the specific omega-6 thought to promote inflammation. The mechanism for this is shown below:
So, while AA is not directly responsible for inflammation, its conversion into prostaglandins does, and the pharmaceutical industry know it. Prostaglandins are not only involved in inflammation but amongst other things, the mediation of pain. Non-steroidal anti-inflammatory drugs, or NSAIDs, act by inhibiting the conversion of AA to prostaglandins by blocking the COX enzymes involved in the conversion.
NSAIDs include medicines such as aspirin, ibuprofen, naproxen and diclofenac (Voltarol)
So should I take an Omega 3-6-9 supplement?
If you’ve been paying attention you should already know the answer. No.
While it may sound like great, and healthy, idea to take a complete omega 3-6-9 supplement, there are some issues. Even if your supplement has the optimum ratio of 3:6:9 fatty acids, the reality is your getting enough omega-6’s though your diet. Naturally, you’re also able to produce as much Omega-9’s as you need, because omega-9 is a non-essential fatty acid and therefore you can synthesise it.
For the mentioned reasons, we’d recommend only supplementing with omega-3 fatty acids. Most of us aren’t getting enough. Alternatively, you could increase the amount oily fish your consuming. Wild caught fish is better because farmed fish are fed an artificial diet that results in low in omega-3 fatty acids.
How much omega-3 to eat depends in large part on how much omega-6 you eat.
Remember the ratio of 3:6 is important, so while increasing your omega-3 intake is recommended, you should also aim to reduce the amount of omega-6’s you’re consuming. Reduce the use of vegetable oils, and foods prepared with them. This includes a lot of the processed, fried and convenient foods we all love, and that can make it challenging.
It’s also a good idea to switch from vegetable oil to something with low omega-6 such as extra virgin olive oil, coconut oil, macadamia nut oil or canola oil.
A large proportion of GLA (good omega-6) from evening primrose oil (EPO) is converted to the anti-inflammatory DGLA (another good omega-6) so if you’re taking an EPO supplement, you don’t need to cut it.
Well I feel I scienced the s**t out of that one! Perhaps I went too deep, hopefully I didn’t lose you along the way. Far too many abbreviations were used, but the take home message is simple: more omega-3 and less omega-6.
