Why Animal-Based Omega-3s are Essential (Why animal-based omega-3 is better than plant-based omega-3) and why krill oil is preferred ( by By Dr. Mercola)

The following is extracted from:

http://articles.mercola.com/sites/articles/archive/2012/11/05/fish-oil-benefits.aspx

Why Animal-Based Omega-3s are Essential

Dietary fish and marine oil supplements such as krill oil are a direct source of EPA and DHA. Plants, on the other hand, contain the parent omega-3, alpha-linolenic acid (ALA), which can be converted into EPA and DHA. However, this conversion is ineffective in general, and appears to get progressively more ineffective with age.

The conversion of ALA to EPA and DHA is typically severely impaired by inhibition of delta 6 desaturase, an enzyme necessary for the conversion. Elevated insulin levels impair this enzyme, and over 80 percent of the U.S. population has elevated insulin levels, so chances are high that you'll be part of this significant majority... Therefore, you want to make sure you get the bulk of your omega-3 from animal sources, not plant sources, to make sure you won't develop a deficiency.

In fact, omega-3 deficiency is likely the sixth biggest killer of Americans, and may be a significant underlying factor in up to 96,000 premature deaths each year.

I prefer krill oil compared to all other animal-based omega-3's because while the metabolic effects of krill oil and fish oil are "essentially similar," krill oil is as effective as fish oil despite the fact that it contains less EPA and DHA.⁸ This is because krill oil is absorbed up to 10-15 times as well as fish oil due to its molecular composition (Its EPA and DHA fatty acid chains are phospholipid bound), and is less prone to oxidation (rancidity) because it is naturally complexed with the potent fat-soluble antioxidant astaxanthin.

Fish oil is in a triglyceride molecule that has to be broken down in your gut to its base fatty acids of DHA and EPA. About 80-85 percent is never absorbed and is eliminated in your intestine (this is why fish oil can cause you to experience burp back and why about half of all people cannot tolerate fish oil). Then once the fatty acids are absorbed into your bloodstream, your liver has to attach it to phoshphatidyl choline for it to be used by your body.

The beauty of krill is that all of it is in the correct form in the original pill, so your body uses virtually 100 percent of it. As a result, most people only need two to three 500-mg capsules of krill oil per day (each capsule typically contains about 50 mg of DHA and 90 mg of EPA) to support optimal brain, and overall, health.