Evolutionally data shows us that our hunter-gatherer ancestors consumed omega-6 fats and omega-3 fats at an approximate ratio of 1:1. Since the inception of the industrial revolution and the subsequent development of the agricultural industry however, this intake has progressively risen to an average of 15:1, with a ratio as high as 25:1 in some parts of the Western world. The two predominate contributing factors to the imbalanced ratio are:
- The modern vegetable oil industry and high level production of these omega-6 based fats;
- Increased use of cereal grains such as corn as feed for domestic livestock. When animals are fed cereal grains, the fatty acid profile of their meat becomes altered, which in turn impacts the quality of the meat consumed.
While both omega-3 and omega-6 are essential fatty acids (EFAs), they cannot be synthesised by the body and therefore must be obtained from food. Higher intakes of omega-6 are linked with the inflammatory cascade and ill health. Let’s take a look at these two oils in more detail.
These are our anti-inflammatory fats, essential for nutrient density, access to fat-soluble vitamins A, D, E and K, satiety, hormonal control, skin integrity, heart health, memory and cognition. Examples include avocado, nuts, seeds, olive oil, sacha inchi oil, flaxseed oil, wild caught salmon, sardines and grass fed animal products.
It is important to acknowledge that plant sources offer omega-3 in predominately alpha linolenic acid (ALA) form, which must be converted to docosahexaenoic acid (DHA). The conversion is relatively low and it is therefore much more efficient to consume DHA direct from animal sources.
The research surrounding the health benefits of omega-3s is clear and eicosapentanaenoic acid (EPA) and docosahexaenoic acid (DHA) offer the greatest benefit. These omega-3 fats are found exclusively in seafood and marine algae, and hence why the consumption of wild caught salmon and sardines is continually encouraged.
Omega-6s are also EFAs but their intake does need to be moderated. Positive health benefits include growth and development, blood pressure regulation, hair growth and heart health, when combined with omega-3s. Examples include walnuts, poppy seeds, sesame seeds, pumpkin seeds and flaxseeds.
What about refined vegetable oils?
These are the one area where you can create the biggest difference to your health. Refined vegetable oils have been found to be highly inflammatory and as discussed, one of the biggest reasons for the imbalanced omega-6 to omega-3 ratio we see in the Western world. Examples include cottonseed, corn, soybean and canola oil.
Unlike expleller or cold pressed oils, these oils must be extracted with a high degree of human interference and often in very unnatural ways. Canola oil, for example, is produced by heating the rapeseed and processing with a petroleum solvent to extract the oil. More heat is then applied and acid is used to remove any solids that occurred during the first phase of processing. Following this, the canola oil is treated with chemicals to improve its colour and remove its harsh smell to produce a more attractive and palatable end product. Not exactly what you would call healthy though is it?
While it may not yet be crystal clear, the key is to focus on predominantly omega-3s and saturated fats, smaller amounts of plant-based omega-6s and remove the refined seed oils.