Is flax oil a good source of Omega-3?
Flax seeds are the richest plant source of Omega-3s, followed by chia seeds and walnuts.
On paper, flax seed oil is the best source of plant / parent Omega-3 available. Many flax oils are over 50% by weight of Omega-3s, and they also have one of the best Omega-3 / Omega-6 ratios of all food sources. It seems like a no-brainer to use it as a super food and take half a teaspoon every day. So what's the problem?
The problem is that flax seed oil is one of the most unstable edible oils. Most polyunsaturated food oils are unstable and should be used with caution, as I explain in Grow Youthful. But flax seed oil can turn from super food to toxic with just half an hour of exposure to hot bright sunlight, or with hours or days of exposure to air, light or heat. Of course, you should never heat it in the kitchen.
I recently succumbed to temptation and bought a bottle of organic flax seed oil in the supermarket. A fresh and undamaged flax oil should have a delicious, nutty and slightly sweet flavour. However, this oil had a less pleasant "seed" rather than nut taste, and was more sour than sweet. When it is rancid, it becomes linseed oil, used to oil cricket bats, and in paint manufacture. Linseed oil has a characteristic oil paint smell, and if there is the slightest hint of that smell in the edible oil, it is rancid.
Animal and plant sources of Omega-3s are different to each other. Oily fish are a good source of Omega-3s (Mackerel, Tuna, Salmon, Herring, Anchovy, Sardines), as are grass-fed animals. Eggs from poultry fed on fresh greens (especially purslane) and natural foods and forage that they can find while free ranging are also a good source. (Eggs from birds fed on stock feed are a poor source of Omega-3).
Plant Omega-3s come in the form of ALA (alpha-linoleic acid). ALA is not much use on its own, and must be inefficiently converted to EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). EPA and DHA is the form that Omega-3s come from animals.
In summary, it is difficult to obtain fresh, undamaged flax seed oil. It is so delicate and unstable that it is usually damaged in the supply chain, even when it comes in an opaque bottle topped with an inert gas, and kept in the refrigerator. In any case, plant-based Omega-3s must be converted to EPA and DHA, a process that is not efficient, and is further inhibited by the Omega-6 fats that are present in nuts and seeds. I feel it is better to eat fresh nuts and seeds to get plant-based Omega-3s, and get your EPA and DHA from free-range, grass-fed, natural-diet meat, eggs and dairy.