Fatty Acids / Omega Oils - a comprehensive guide


Fatty Acids / Omega Oils


You probably know that some fats are good for us, and even essential for our health. They can support heart health, brain health, our eyes, balanced cholesterol levels, our skin, and more.

If you’re looking to buy a fatty acid/omega oil supplement, you’ll know that the choice is huge, and can often be bewildering. How do you know whether to choose omega-3, omega-6, omega-9 or combinations? What’s the difference between fish oil and other omega-3s? And what dosage should you take? Read on to find out more!

Why are fats important for our health?

Fats are vital for our health for many reasons. Here are just some of them:

  • Fats form part of all our cell membranes – without them, our cells wouldn’t function properly.
  • Our brains are made of about 60 per cent fat!
  • Fats are needed for the myelin sheath around our nerve cells, which allows messages to travel normally around our body.
  • Sex hormones such as oestrogen, testosterone and progesterone are made from fats. Without these fats, we wouldn’t be able to reproduce!
  • Fats are needed for us to absorb fat-soluble vitamins such as vitamin D and vitamin A; and the vitamin D produced in our body is made from fat.
  • Fats are needed to make ‘signalling molecules’ such as eicosanoids that control inflammation for healing and repair.
  • Fats help to make our skin waterproof.

What are ‘essential fatty acids’?

You may have heard this term but not really know what it means. The term ‘essential fatty acids’ means fats that are essential for our health and that the human body can’t make itself from substances. Strictly speaking, there are only two essential fatty acids: an omega-3 fat called alpha-linolenic acid (ALA) and an omega-6 fat called linoleic acid (LA). Omega-3 ALA is found in the highest amounts in flaxseeds and chia seeds and their oils, with much smaller amounts found in other nuts and seeds. Omega-6 LA is found in high amounts in most other seeds and nuts and oils made from them. Both are also found in smaller amounts in other plant foods and animal foods.

From these essential fatty acids, the human body can make longer-chain omega-3 fats such as EPA and DHA, as found in fish; and longer-chain omega-6 fats such as GLA, as found in evening primrose oil for example.

Other important omega-3 and 6 fatty acids and their functions

So if these two fatty acids are the only essential ones, why is it beneficial to consume the other longer-chain omega-3 and 6 fats, such as the omega-3s in fish oil?

Basically, the body’s conversion of the two essential fatty acids to these other fats may not be very efficient. It requires several steps, which need various enzymes to be working in the right way, and requires the right ‘cofactor’ vitamins and minerals to be available. This means that deficiencies in vitamins and minerals, and other factors such as stress, smoking, poor diet, chronic illness and even genetic differences may affect the conversion. For example, research has shown that the amount of omega-3 ALA (as found in flaxseeds) converted all the way to DHA in the human body may be less than 1 per cent in some individuals.[1]

So now let’s have a look at why these other, longer-chain fats can be beneficial.

Omega-3 EPA and DHA

EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are found primarily in oily fish (salmon, sardines, mackerel and anchovies), fish livers, and fish oils. They have very specific roles in the body. For example:

  • DHA is found in high levels in the brain. It is vital for normal brain development in infants, and contributes to the maintenance of normal brain function at all ages.
  • Both EPA and DHA are important for heart health, including heart function and maintaining normal blood pressure and triglyceride levels (triglycerides are fats that are associated with heart disease in high levels).
  • DHA is important for the eyes and vision. It is found in high concentrations in the retina of the eye, and is vital for normal eye and vision development in infants.
  • EPA and DHA may may have an anti-inflammatory EPA can be converted into specific types of ‘eicosanoids’ (signalling molecules) that have anti-inflammatory activity in the body. EPA and DHA may also help to balance inflammation in other ways, such as by producing substances called ‘resolvins’ and ‘protectins’[2].
  • EPA in particular may be beneficial for mood.[10]

All of these are reasons why it can be helpful to either make sure we’re eating oily fish regularly, or taking a fish oil supplement, or both.

For vegetarians and vegans or others who are not able to eat fish or take fish oil, there are plant-sourced DHA and EPA supplements available, sourced primarily from algae. You can read more about this in ‘How to choose a fatty acid / omega oil supplement’, below.

Omega 6 GLA

GLA – gamma linolenic acid – is an omega-6 fatty acid. In foods, it may be found in small amounts in pine nuts, organ meats, chicken and some fish. It can also be found in supplements of evening primrose oil, starflower (borage) oil and blackcurrant seed oil.

Like EPA and DHA, GLA is not considered essential as it can be made from the ‘parent’ omega 6 linoleic acid. However, once again, conversion may be poor; and so using GLA directly may have specific benefits in the body.

  • GLA can have anti-inflammatory GLA is converted to another fatty acid called DGLA, which is then converted into anti-inflammatory substances such as prostaglandin E1.[3] It has been found to be helpful for those with rheumatoid arthritis through its anti-inflammatory action.[6]
  • GLA may be supportive for those with eczema and dry skin. It’s thought that eczema may be related to a deficiency of the enzyme that converts the essential omega-6 LA into GLA, and so taking GLA itself may be helpful.[4,5]
  • Evening primrose oil (containing GLA) may be supportive for women with premenstrual syndrome, breast pain and menopausal hot flushes. [7,8,9]

What about omega-9 fatty acids?

When we refer to omega-9 fatty acids, we generally mean oleic acid, which is found in high amounts in olive oil. This is not an essential fatty acid, as our body can make it from other fats; however, oleic acid is thought to be the primary reason for the health benefits of consuming olive oil. It may promote heart health, including supporting healthy blood cholesterol levels.

Apart from olive oil, other food sources of omega-9 oleic acid include nuts such as macadamia nuts, hazelnuts, pecans and almonds; as well as avocadoes. Animal fats such as chicken and beef fat contain significant amounts of oleic acid too, although they can contain more saturated fat than olive oil and nuts. 

Most of us have a lower need for supplementation of omega-9 fatty acids, unless we don’t eat much of these food sources in our diet. They are sometimes found omega-3-6-9 blends in supplement form.

Deficiency signs and symptoms*

Fatty acid deficiency signs and symptoms may include:

  • Dry skin, itchy, peeling skin, or skin conditions such as eczema
  • Dry hair
  • Increased inflammation and pain
  • Hormonal imbalances
  • Poor wound healing
  • Increased thirst
  • Changes in memory or cognitive function
  • Eye problems such as eye strain or blurred vision

*Note that many of these symptoms can be indications of other health conditions or deficiencies – please consult your doctor or health practitioner if you are concerned.

How to choose a fatty acid/omega oil supplement: Lifestyle Labs’ recommendations

There seem to be endless choices when it comes to fatty acid supplements – in types, dosages and combinations. For this reason, it is always helpful to get some guidance from a nutritional practitioner. However, the following guidelines may help you.

Omega-3, omega-6, omega-9 or combinations?

This can be a difficult one to decide if you haven’t had any personalised guidance. In general, more people are in need of omega-3 fats compared to omega-6 and omega-9, as they are harder to get in our diet (unless we eat lots of oily fish). However, omega-6 GLA (often in combination with omega-3) may be advised if you have any of the conditions that GLA may benefit: including skin problems, hormonal imbalance, or inflammatory conditions such as rheumatoid arthritis. Omega-9 is generally not considered as important and is not taken on its own in supplements.

Which omega-3 supplement to choose?

  • Remember that EPA and DHA in fish oils can have different (and probably greater) benefits than omega-3s from plant sources such as flaxseed oil.
  • Check the amount of EPA and DHA you are getting in fish oils. A bottle labelled ‘Fish Oil 1000mg’ may contain just a small amount of EPA and DHA (e.g. 300mg total) but others may be almost pure EPA and DHA (i.e. 1000mg total). This can also account for the difference in price between supplements. Check the back of the label carefully. In general, the more concentrated the better, as you will need to take less to have the same benefits.
  • Higher EPA, higher DHA or similar amounts of both? This is another difference you will see between fish oil supplements. The jury is out on which is the best, with different research supporting different combinations. As a general guideline, those with inflammatory conditions such as arthritis, general aches and pains, or low mood may do better with a higher-EPA supplement; but those who need support for brain health and memory or eye health may be better off choosing a higher-DHA supplement or a more balanced EPA-DHA ratio. Heart health may benefit from either, or from a balanced ratio of both.
  • If you are vegetarian or vegan or can’t consume fish, then you can find DHA (and a small number of EPA-DHA) supplements sourced from algae.

Which omega-6 supplement to choose?

Evening primrose oil, starflower (borage) oil, or blackcurrant seed oil? Evening primrose is the most traditional form of GLA supplementation and the most widely studied. However, starflower oil tends to be more concentrated, so can give you a higher amount of GLA per capsule. Blackcurrant seed oil is just another alternative to either.

Liquids, capsules or other forms?

  • In fish oils, you can find good quality – and high-concentration – products in both liquid and capsule form. So whether you choose one or the other can just come down to personal preference.
  • If you have digestive problems or know that you don’t absorb fats very well, then try an emulsified liquid fish oil supplement. Emulsified fats are broken down into tiny particles to make them much easier to absorb. They are often in a fruit base and look and taste like syrups rather than an oil.
  • If you prefer to take omega-3 in the form of alpha linolenic acid (ALA, the essential omega-3 fatty acid from seed oils), then it is better to go for a liquid flaxseed oil or chia oil rather than a capsule, and take a teaspoon or more per day. Remember that the conversion from ALA to the more useful EPA and DHA can be quite poor, so you need to take more for it to be effective.
  • Omega-6 GLA in evening primrose oil, starflower oil or blackcurrant seed oil is mainly found in capsules rather than liquids.

Fatty acid/omega oils for children

Fatty acid or omega oil supplements that are suitable for children should say so on the label or in the supplement information.

Most supplements for children are based on omega-3 fats, sometimes with a smaller amount of omega-6 and/or omega-9. Omega-6 GLA is not generally given to children on its own unless advised by a practitioner.

Your choice of omega-3 supplement may depend on:

  • The age of the child. Again, the supplement information or label should say from what age the product is suitable. If in doubt, consult a nutritional practitioner or the supplement brand directly.
  • Whether your child prefers liquids, chewable gummies or capsules (for older children). This can be trial and error, as one form is not necessarily better – or better accepted – than another!


If you are taking any medications or have any medical condition, please consult your healthcare practitioner before taking a fatty acid / omega oil supplement. Particular caution is advised with anticoagulant medication.   



  1. Arterburn LM et al. Distribution, interconversion, and dose response of n−3 fatty acids in humans. Am J Clin Nutr. 2006 Jun;83(6 Suppl):1467S-1476S.
  2. Lorente-Cebrián S et al. An update on the role of omega-3 fatty acids on inflammatory and degenerative diseases. J Physiol Biochem. 2015 Jun;71(2):341-9.
  3. Fan YY, Chapkin RS. Importance of dietary gamma-linolenic acid in human health and nutrition. J Nutr. 1998 Sep;128(9):1411-4.
  4. Simon D et al. Gamma-linolenic acid levels correlate with clinical efficacy of evening primrose oil in patients with atopic dermatitis. Adv Ther. 2014 Feb;31(2):180-8.
  5. Kawamura A et al. Dietary supplementation of gamma-linolenic acid improves skin parameters in subjects with dry skin and mild atopic dermatitis. J Oleo Sci. 2011;60(12):597-607.
  6. Leventhal LJ, Boyce EG, Zurier RB. Treatment of rheumatoid arthritis with gammalinolenic acid. Ann Intern Med 1993;119:867-73.
  7. Horrobin DF. The role of essential fatty acids and prostaglandins in the premenstrual syndrome. J Reprod Med. 1983 Jul;28(7):465-8.
  8. Pruthi S et al. Vitamin E and evening primrose oil for management of cyclical mastalgia: a randomized pilot study. Altern Med Rev. 2010 Apr;15(1):59-67.
  9. Farzaneh F et al. The effect of oral evening primrose oil on menopausal hot flashes: a randomized clinical trial. Arch Gynecol Obstet. 2013 Nov;288(5):1075-9.
  10. Dyall SC. Long-chain omega-3 fatty acids and the brain: a review of the independent and shared effects of EPA, DPA and DHA. Front Aging Neurosci. 2015 Apr 21;7:52



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      Dr. Lifestyle

      Dr. Lifestyle is our own collective of leading health, nutrition and fitness experts. Having several brains makes it really hard to decide what we feel like for breakfast (Chia Coconut Pudding, or a Green Smoothie?), but when it comes to health advice we are an all-knowing, hyper-intelligent, super human.