Alpha-linolenic acid is one of the primary fatty acids found in various seeds, nuts and grains. Some of the highest levels are found in chia seeds (64%), kiwi fruit seeds (62%), flax seeds (55%) and hemp seeds (20%). Other good sources include walnuts, pumpkin seeds, sesame seeds, olives, canola, kale, spirulina, spinach and others.
In addition to being well utilized by the body, alpha-linolenic acid (ALA) is also converted to docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and other important omega-3s within the body. The primary liver enzyme used in the conversion of ALA to DHA is delta-6 desaturase. DHA converts to EPA in the body as needed. A healthy person will convert ALA to DHA at a rate of from 7% to 15% according to research.
For those who convert ALA to DHA at a slower rate, algal DHA provides the purest form of DHA. DHA is produced by algae and travels up the sealife food chain. Algal DHA does not contain saturated fats as many fish do. DHA-producing algae is farmed in tanks in the absence of mercury, PCBs and dioxins that have been known to bioaccumulate within fish.
DHA and EPA are the central fatty acids in fish oil besides saturated fat. It also should be noted that fatty fish such as salmon also contain a considerable amount of arachidonic acid. Foods rich in arachidonic acids have been shown to increase inflammation in the body.