Why not just eat flaxseed?
The Omega 3 fatty acids in flax seed / flax seed oil are the ALA (alpha linolenic acid) fatty acids, all of which are polyunsaturated. Flax and its oil are perhaps the most widely available VEGETARIAN/BOTANICAL source of Omega−3. Flaxseed oil consists of approximately 55% of total oil as ALA.
Here is a problem:
The Omega-3 in American diet has decreased gradually over time with the increased consumption of processed foods. On the other hand dietary levels of Omega-6 fatty acids have increased due to consumption of oils that are rich in Omega-6 fatty acids. This dietary imbalance of the omega fatty acids has created an unfavorable ratio of Omega 3 to the Omega 6 in our bodies.
It is not just the amount of Omega-3 consumed but the amount of Omega-3 in relation to the amount of Omega-6 oils consumed that is important to keep the ratio to a favorable level of 1:4 (Omega 3 to Omega 6). Flaxseed provides one of the only non-animal sources of Omega-3 that contains significantly more Omega-3 than Omega-6.