There are a lot of conflicting views in nutrition, however, one point that is universally agreed upon is the importance of balancing omega 3 fatty acids with omega 6 fatty acids in the diet.
Omega 3 fatty acids
Omega 3 fats are a type of polyunsaturated fat that is present in both animal and plant sources of fat. The richest sources of it come from salmon (fresh, smoked and canned), mackerel, sardines, herrings and New Zealand grass-raised cattle. These foods contribute eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) omega fatty acids.
Plant-based sources include avocados, green leafy vegetables, walnuts, flax seeds and chia seeds. These supply alpha-linolenic (ALA) acid, which is more common in our everyday diet than EPA and DHA.
These omega 3 fats are an important part of our cell membranes and help synthesise brain neurotransmitters (which communicate between our brain and body) and molecules of the immune system. They help with maintaining elasticity of our arteries and together, these benefits are likely responsible for the reduction of risk, found when research has investigated omega 3 fat intake and cardiovascular disease, arthritis, neurological disorders, type 2 diabetes and other inflammatory conditions.
DHA in particular is necessary for the growth and development of the brain and retina of a foetus during pregnancy and make up a substantial amount of fat in the brain, which continues to grow until around a child is 5 to 6 years old. EPA, on the other hand, appears to be responsible for helping improve mood disorders.
There is also convincing research to show a positive relationship between intake of EPA and reduced risk of depression (both primary depression and post-natal depression), lower rates of self-harm and suicide.
Both DHA and EPA may play a role in reducing risk of schizophrenia and personality disorders. While ALA (found in plant-based sources) is important, the most potent health benefits come from the longer chain EPA and DHA. The conversion of ALA into these is minimal (up to 5 per cent of ALA is converted into EPA and DHA) for people who do not include marine or animal-based sources in their diet.
These benefits are the likely reason why, in New Zealand, fish oils are the most commonly consumed supplement as reported by the New Zealand Adult Health Survey 2008/09.
Omega 6 fatty acids
Omega 6 fats also play a role in the production of hormones and molecules that regulate inflammatory pathways. Significant sources of omega 6 fats are present in the same plant sources (avocados, some nuts and seeds and green leafy vegetables) and, in the correct dietary ratio with omega 3 fats, contribute to reducing inflammation, particularly in the premenstrual period for women.
However, in the modern diet, the biggest contribution of omega 6 fats come from processed and packaged foods, as the vegetable and seed oils are a by-product of the grain industry and a cheap source of calories for food manufacturers.
The ratio of omega 6 to omega 3 fats in the current western diet is estimated to be around 16:1 — far exceeding the optimal ratio of 4:1.
This is evident as we can measure markers of omega 6 fats in our body fat stores which have increased by over 200 per cent in the last 50 years. High amounts of omega 6 are positively associated with increased risk of cardiovascular disease, depression and other mood disorders. Definitely too much of a good thing.
The best action to take
In terms of the omega 6 to omega 3 ratio, focus on reducing the amount of omega 6 fats in the diet, while increasing good sources of omega 3, particularly the marine sources rich in EPA and DHA. An easy target is to start reducing the amount of processed food consumed, rather than reducing consumption of avocado, nuts, seeds or leafy greens. The latter contribute a host of health benefits and are good sources of all fatty acids, not just the omega 6 fats.
Truth be told, these foods aren’t the reason why the omega 6 fats are prolific for all but a few people.
Crackers, biscuits, margarine, commercial salad oil dressings and mayonnaises and vegetable oils, such as soy and sunflower oils, are among the significant sources of these omega 6 fats. Read the back of the food label to choose products that use olive oil, coconut oil or butter as the major source of fat and choose natural, whole foods where possible. Making your own mayonnaise is a really good way to ensure the quality of your fat source.
Increasing your omega 3 intake will also help restore some balance. The recommended amount per day is 500mg or 3500mg across a week. This can be easily met if you include a couple of salmon meals per week. However, studies investigating the benefits of EPA and DHA have been conducted using amounts of 2g-4g of fish oil per day and for some people, these doses may be required for the more therapeutic benefits seen in the research studies.
While this dose is still considered moderate, it’s important for anyone considering supplementation to discuss this (and all supplements) with their health and nutrition professional. A fish oil supplement may not be appropriate for some, particularly people who are taking blood-thinning medication, who may have surgery in the near future, or people with blood-clotting problems. They can help determine the appropriate amount and where to source the best supplement.
As with most things nutritional, the first place to tackle your nutrients is through your diet. The changes suggested will go a long way to improving the ratio of omega 6 to omega 3 in your diet.
1 cup 'light' olive oil (if you don't want an olive oil taste) or another nut oil such as avocado
½ tsp sea salt
1 Tbsp raw apple cider vinegar
Mustard powder, cumin, ginger, other spices and herbs to vary flavour, optional
- Crack the egg into a jar that is just bigger than a stick blender. Add salt, oil and vinegar.
- Using a stick blender whizz for about 30-45 seconds. Will last up to 5 days.
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Watch and learn
Learn how to make mayonnaise with Ray McVinnie
Mikki Williden is a registered nutritionist and lecturer at AUT University, where she lectures in public health nutrition and sports nutrition at the School of Sport and Recreation. Read Bite articles from Mikki or visit mikkiwilliden.com for more.