OMG! – Omega-3 and 6

Have you ever wondered why we are told to eat more omega-3, why is omega-6 considered the ‘bad one’, is oily fish really the best source of omega-3 and why are they called ‘essential’ fatty acids?

I feel like I’ve gone back to science lectures to try and make sense of this topic! Firstly it is not simply a case of the ‘bad’ one, the real problem is the ratio. A typical western diet causes the ratio to become unbalanced. Typically 16:1 (omega-6 to 3) or higher, rather than the desired 4:1 or ultimate 1:1 ratio. We do need both omega-3 and 6 in our diets, but an imbalance between them is linked with serious health issues. There is a cap on the total amount of the two that the body can use, so they end up competing for space, therefore too much omega-6 can block omega-3.

In short elevated omega-6 intakes are associated with an increase in all inflammatory diseases – which is to say virtually all diseases. The list includes (but isn’t limited to); cardiovascular disease, type 2 diabetes, obesity, metabolic syndrome, irritable bowel syndrome & inflammatory bowel disease, macular degeneration, rheumatoid arthritis, asthma, cancer, psychiatric disorders, autoimmune diseases.

This is not a simple subject, so I’ve summarised the key messages:

  • The main reason for the imbalance and high omega 6 levels is processed seed and veg oils and foods containing these oils (chips, crisps, snacks, cakes etc). These oils are cheap so they are in a lot of processed foods.
  • Follow this link for a detailed list of omega-3 and 6 in foods. Interestingly butter and cow and sheep fats are preferable to the majority of seed and veg oils
  • Appreciate the need to balance your intake. Focus on reducing omega 6 intake as well as eating more omega 3.
  • As we are all becoming aware of the need to increase omega-3 it is being used as a marketing tool. Be cautious of omega 3 being used in marketing to promote foods. Learn which foods naturally contain omega-3 and avoid foods being fortified with omega-3, this is more about sales than health.
  • Rethink chicken and turkey fats, especially intensively farmed products due to very high omega 6 levels.
  • It is true that oily fish is the main source of 2 of the 3 omega-3s, but these can also be obtained from microalgae, see notes below.
  • Whilst omega-3 is promoted in foods, in converse you will not see warning that foods are high in omega-6, so you need to be aware when making food choices. For example look at a mayonnaise label, it lists omega-3 as a way of promotion but not that it has over 7x that amount of omega-6, making the ratio 7:1 which doesn’t make it a good source of omega-3.
  • Natural unprocessed foods containing high ratio’s of omega-6 to 3 are considered to be less harmful than processed foods. So it is believed to be high levels of omega-6 in processed foods that are the main focus.
  • Eating whole fish versus fish oil as a source of omega-3 is preferable.
  • Grass fed meat and dairy has a better ratio of omega-3 to 6. Whilst this should be a consideration, the key message to take from this is grass fed is healthier in general, but the difference is negligible when compared to the impact of processed oils in our diet.

Let’s take a closer look;

Omega-3 – Since the human body can’t produce omega-3 and 6, these fats are referred to as “essential fats,” meaning that you have to get them from your diet.

Omega-3 fats are a crucial part of human cell membranes, with important benefits for your heart, brain and metabolism. They also have a number of other important functions, including, improving heart health, supporting mental health, reducing weight and waist size, decreasing liver fat, supporting infant brain development, fighting inflammation, preventing dementia, promoting bone health, preventing asthma. Unfortunately, the Western diet does not contain enough omega-3s.

There are three types of omega-3; ALA, EPA and DHA. ALA can be obtained for plant based foods, but EPA and DHA are mainly found in oily fish or microalgae, but can also be found in smaller quantities in milk, eggs and meat from animals that have consumed a natural diet high in omega 3. ALA converts to EPA efficiantly but larger quantities are needed to convert to DHA so people not eating the recommended amount of oily fish or for vegans and vegetarians it is recommended to take a supplement such as algae oil as a source of DHA

Examples omega-3 by type in percentages, e.g. 2% equals 2g per 100g.

  • Chia seeds:        17.8% ALA
  • Salmon:                2.0% EPA and DHA
  • Mackerel:             2.0% EPA and DHA
  • Walnuts:               9.0% ALA
  • *Linseed oil:       53.4% ALA
  • *Linseeds:          22.8% ALA
  • Sardines:              2.2% EPA and DHA

* Linseed is also know as flaxseed. It needs to be milled (crushed) for us to digest it. So whilst you will burn calories crushing your own! it is advised to looked for the milled option.

Omega-6 fats are also necessary for survival, but they’re not nearly as beneficial as omega 3s. Omega 6 fats help with brain function, muscle growth, and hormone production, but they also cause inflammation, and they compete with omega 3s in the body. The ideal is to eat just enough omega 6s to function, but no more, and to balance them with lots of omega 3s

See the chart below for example ratios in oils, understood to be the main cause of high omega-6 intake:

efa content of oils

Parting thoughts – There is strong scientific evidence that there is an issue with the imbalance in our diets. It is a hard topic to get exact answers to every question past the obvious but what is clear is that again our western diet and intake of processed foods is the real issue here. The closer we can stick to a whole food, plant based diet with naturally raised products, including any animal products, the better off we will be.







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