You can see from the diagram, in topic 6.6. Fatty Acid Composition of the Diet, that the metabolism of omega 6 and omega 3 compete for the same pathways. In other words, they require the same enzymes and nutrients for conversion. Therefore eating plant-based omega 3 sources may not give you much benefit in respect of producing anti-inflammatory compounds but it will to some degree help stop the production of the inflammatory prostaglandins on the omega 6 pathway.
As has been outlined, the essential fatty acids are the metabolic precursors to prostaglandins. EPA and DHA are actually metabolised to form series 3 prostaglandins (EPA more so). These are the ones that are the most potently anti-inflammatory, and an increase in their production can influence inflammatory events very quickly indeed. Consuming good quantities of omega 3 fatty acids encourages our body to produce more of the anti-inflammatory prostaglandins. The benefits of omega 3 on heart health are well documented and have been studied widely for at least 20 years. However, in recent years we have found that omega 3 intake benefits other aspects of the metabolic disease storm that we are weathering.
Increased omega 3 intake is associated with improved insulin production, utilisation and sensitivity. A study of 126 adults in rural British Columbia, Canada found that increased omega 3 intake was negatively associated with insulin resistance. This is a population-based observational study, and only shows associations rather than cause and effect, but some experimental studies have offered compelling support. A small experimental study conducted by Tsitouras et al in (2008) found that individuals that ate 720g of fatty fish per week and took 15ml of sardine oil daily, had greater insulin sensitivity after 8 weeks, than those who had the control diet.
There are many more of these small experimental studies and population-based studies around. While more research is needed, it certainly looks like a pattern is emerging, and when viewed from a logical, physiological point of view, then it makes sense. At the end of the day, the massive health benefits associated with increased omega 3 fatty acids across the board means that even if this observation proves not to hold true, there will be no harm and only benefit.
As is becoming obvious, our fatty acid intake does become a bit of a balancing act. As you can see, omega 3 fatty acids are a pretty important part of the picture, and too much omega 6 can cause a problem. It is therefore vital that we get the balance right. With the current trends arising from research, the recommendation now is to aim for a 2:1 ratio in favour of omega 3. This means we need to be eating more omega 3 than omega 6 in order to maximise the potential benefits and counteract any negative effects of omega 6.
Thankfully this is pretty easy in practice. The first step is to avoid most vegetable oils like the plague. These apparent ‘heart healthy’ oils like sunflower oil, corn oil, or the generic vegetable oil. These are almost pure omega 6 and will send your levels rocketing up very fast. In place of these oils, there are two cooking oils to choose from. Olive oil is the first. This isn’t an issue as there is no omega 6 in olive oil and the dominant fatty acid is oleic acid which comes into a 3rd category – omega 9.
Omega 9 fatty acids have zero influence on omega balance and don’t present a problem at all. The other oil we recommend is coconut oil. This is best for high-temperature cooking as it is completely heat-stable. Also, the fatty acids found in there, medium chain triglycerides, are rapidly broken down and used as an energy source, so their impact on postprandial lipaemia (elevation of blood fats after a meal) is minimal.
The next step in aiming for omega balance is to drastically cut back on processed foods. This is good advice for a million and one reasons but in terms of omega balance, many processed foods will use untold amounts of vegetable oils. They are cheap as chips, and for decade’s food manufacturers have been under pressure to reduce saturated fat in foods, so moved over to cheap vegetable oils as an alternative. Most ready meals, pre-made sauces etc. will have a lot of omega 6 in them. Get back to basics and get cooking from scratch as much as you can.
Lastly, we need to up the omega 3. The first and most obvious place to start is by eating oily fish around 3 times per week. You could also consider supplements, however, medications such as warfarin, and heparin injections interact with fish oil supplements so please consult a nutritional therapist or doctor before considering supplementation.