Algae-Based DHA vs. Flax

 I also agree with you that omega 3 is easily satisfied with a vegan diet without supplementation

ALA is not converted effectively to DHA under the condition that one is consuming too many omega 6 fatty acids. Since most whole plant foods contain good rations of omega 6 : omega 3, this is of no concern. The National Academy of Sciences does not recognize EPA and DHA as essential. This means there is enough evidence for them to conclude that we can make enough of it without eating it in its preformed state.

In addition…

Do vegetarians have to eat fish for optimal cardiovascular protection?1–3
Am J Clin Nutr 2009;89(suppl):1S–5S.

Interest in the cardiovascular protective effects of n–3 (omega-3) fatty acids has continued to evolve during the past 35 y since the original research describing the low cardiovascular event rate in Greenland Inuit was published by Dyerberg et al. Numerous in vitro experiments have shown that n–3 fatty acids may confer this benefit by several mechanisms: they are antiinflammatory, antithrombotic, and antiarrhythmic. The n–3 fatty acids that have received the most attention are those that are derived from a fish source; namely the longer-chain n–3 fatty acids eicosapentaenoic acid (EPA; 20:5n–3) and docosahexaenoic acid (DHA; 22:6n–3). More limited data are available on the cardiovascular effects of n–3 fatty acids derived from plants such as a-linolenic acid (ALA; 18:3n–3). Observational data suggest that diets rich in EPA, DHA, or ALA do reduce cardiovascular events, including myocardial infarction and sudden cardiac death; however, randomized controlled trial data are somewhat less clear. Several recent meta-analyses have suggested that dietary supplementation with EPA and DHA does not provide additive cardiovascular protection beyond standard care, but the heterogeneity of included studies may reduce the validity of their conclusions. No data exist on the potential therapeutic benefit of EPA, DHA, or ALA supplementation on those individuals who already consume a vegetarian diet. Overall, there is insufficient evidence to recommend n–3 fatty acid supplementation for the purposes of cardiovascular protection; however, ongoing studies such as the Alpha Omega Trial may provide further information.

200 mg per day of DHA (long-chain omega-3 fatty acid) has been shown to offer cardio-vascular protection. A 2011 meta-analysis found that 250 mg/d of n-3 LCFA (DHA and EPA) should be considered a minimum target intake for the prevention of cardio-vascular disease (1). One gram (1,000 mg) of fish oil contains about 300mg EPA and 200mg DHA. Greater than 3 grams per day may increase bleeding in some individuals. For additional cardiovascular protection vegans may want to include foods high in the short-chain omega-3 fatty acids such as flaxseed, chia seeds and walnuts in their diet.

Unfortunately, many Naturopathic Doctors recommend mega-doses of omega-3 fatty acids (1-3 grams fish oil) to their patients because their normal patient is usually someone eating the Standard American Diet (SAD) high in omega-6 fatty acids (grains and grain seed oils) and saturated fats (meats, dairy) and very low in omega-3 fatty acids (green leafy vegetables, walnuts, flaxseed, chia seed). This diet style creates inflammation and the larger doses of omega-3′s may help to decrease it.

However, a healthy diet of unrefined, plant-based whole foods rich in vegetables, fruits, unrefined grain, beans and legumes, with a few ounces of raw nuts or seeds is anti-inflammatory; therefore, high doses of DHA/EPA may not be necessary, nor optimal.

1. Musa-Veloso, K., et al. Impact of low v. moderate intakes of long-chain n-3 fatty acids on risk of coronary heart disease. British Journal of Medicine (2011), 106,1129-1141.