Essential Fatty Acids
What are essential fatty acids?
Essential fatty acids (EFA’s) are a group of saturated fatty acids that your body needs for several important purposes, including cellular functions, mood and behaviour modulation, dealing with inflammation and certain DNA functions. They are called ‘essential’ because your body cannot make them from scratch and so you need to obtain them from your diet.
There are several two main groups of EFA’s – omega-3 and omega-6.
The most important omega-3 fatty acids are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Plants only contain ALA but your body also needs EPA and DHA; while these other omega-3 fatty acids can be manufactured by your body from ALA, the process is quite inefficient and so you need quite a bit of ALA in your diet every day to ensure adequate amounts of these other omega-3’s.
It is thought that fish consumption by our ancestors has led to a dependency on EPA and DHA as fish are high in these omega-3’s. Interestingly though, these fatty acids are not produced by the fish themselves, but come from some of the algae they eat. This is why, instead of having to take a fish oil supplement to get enough EPA and DHA, you can now take vegan algae-based supplements instead, including Chlorella and Spirulina. These are actually a lot better for you as fish oil can contain unsafe levels of contaminants and is sometimes high in mercury and other environmental toxins that have no place in a healthy diet.
How efficiently does the body convert ALA to EPA and DHA?
The human body can convert ALA to EPA, and EPA to DHA, but the efficiency, and sufficiency for optimal health, of this conversion is controversial. Studies have found EPA and DHA levels in vegans to be about two thirds lower than in people who eat meat. The extent to which this poses a health risk is not yet known, but vegans have been advised to increase their intake of alpha-linolenic acid, and reduce their intake of omega-6 fatty acids and saturated fatty acids, which can limit the rate of conversion. Recently, some companies have begun to market vegan DHA supplements containing seaweed extracts. Whole seaweeds are not suitable for supplementation because their high iodine content limits the amount that may be safely consumed.
The most common estimate for ALA -> DHA conversion is that the body converts about 20% of ALA to DHA.
Where can I obtain ALA, EPA and DHA?
You can get ALA from flax (linseed), either in powdered (it is important to grind flax to make the ALA bioavailable) or oil form. This is the best easily available source of ALA. You can also find α-linolenic acid in seed sources such as chia, perilla, hemp, rapeseed (canola), and soybeans as well as in English walnuts. EPA and DHA are available from Chlorella and Spirulina supplements, which you can find at most health stores these days.
Omega-6 fatty acids include linoleic acid (LA), gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA) and arachidonic acid (AA).
The biological effects of the omega-6 fatty acids are largely mediated by their interactions with omega-3 fatty acids (See the Essential fatty acid interactions article on Wikipedia for more information.)
Some medical research suggests that excessive levels of omega-6 fatty acids relative to omega-3 fatty acids may increase the probability of a number of diseases and depression. Modern non-vegan Western diets typically have ratios of omega-6 to omega-3 in excess of 10 to 1, some as high as 30 to 1. The optimal ratio is thought to be 4 to 1 or lower. In other words, most people get TOO MUCH omega-6 (relative to omega-3) in their diets.
This interferes with the health benefits of omega-3 fats and may aggravate or cause prothrombotic, proinflammatory and pro constrictive conditions. Chronic excessive production of omega-6 is associated with heart attacks, thrombotic stroke, arrhythmia, arthritis, osteoporosis, inflammation, mood disorders and cancer!
Where can I obtain LA, GLA, DGLA and AA?
Vegan sources of omega-6’s include cereals, whole-grain breads, nuts, most vegetable oils, evening primrose oil (GLA specifically), borage oil, blackcurrant seed oil, linseed oil, soybean oil, cottonseed oil, sunflower seed oil, corn oil and safflower oil.
Many vegan supplements also contain omega 6 in a healthy ratio to omega-3 and omega-9.
As too much omega-6 relative to omega-3 is unhealthy, rather focus on ensuring adequate omega-3 intake – it’ll be almost impossible for you not to get enough omega-6’s in your diet!
What about omega-9’s?
Unlike omega-3 and omega-6 fatty acids, omega-9 fatty acids are not classed as essential fatty acids. This is both because they can be created by the human body from unsaturated fat, and are therefore not essential in the diet.
Include at least one of the following daily:
- 2 tablespoons (30ml) of ground flaxseeds or chia seeds
- ¼ cup (60 ml) of hemp seeds
- ⅓ cup (85 ml) of walnuts
- 1½ teaspoons (7 ml) of flaxseed oil
- 1½ tablespoons (22 ml) of hempseed oil
- 2½ tablespoons (37 ml) of canola oil
For more information on EFA’s, visit Vegan Outreach.