There are a number of omega-3 fats within the family of omega-3s. Let's start with the most beneficial omega-3s. Ideally, the most beneficial omega-3s are derived from fish and fish oils (called EPA and DHA, or long chain omega-3s), but that poses a challenge for vegans who don't eat foods of animal origins. Fortunately, there are plants sources of long chain omega-3s. A company, Martek Biosciences, makes an oil (called DHASCO) that is derived from algae (Crypthecodinium cohnii) that is 40% DHA. Over 140 commercial products contain DHASCO (including non-gelatin capsules) at the following website.
Another product that is on the horizon is the SDA (stearidonic acid), a natural long chain omega-3 fat that acts similarly to EPA. SDA is not generally found in most terrestrial plant sources and is rarely found in commonly consumed vegetables, fruits, seeds, nuts, or commercial oils. This omega-3 fat is generated in a new soybean oil (Monsanto Co, St Louis, MO) specifically designed to contain 20-30% SDA (see enclosed references). While this product is yet to be commercially available, it has been granted GRAS status (generally recognized as safe), as approved in 2009 for general commercial use by the Food and Drug Administration (FDA). One drawback for some is that this is a genetically modified plant source using genes from fungal and rapeseed sources (both plant sources). SDA can also be found in lower amounts in the not so common borage and echium oils. By weight, echium oil is the richest commercially available plant source of SDA (3.5-9.0%), followed by species of the Grossulariaceae family (i.e., currant seed oils, Ribes nigrum) at 2-6% and Seaweed (Undaria pinnatifida).
