In many of the aquatic animals where it can be found, astaxanthin has a number of essential biological functions, ranging from protection against oxidation of essential polyunsaturated fatty acids, protection against UV-light, pro-vitamin A activity and vision, immune response, pigmentation, and communication, to reproductive behavior and improved reproduction.²Some of these unique properties of astaxanthin have also been found to be effective in humans as well.^{3 4 5 6}

Crustaceans and other aquatic animals (as well as mammals) are unable to produce astaxanthin. This means it must be acquired from the diet as is the case with other carotenoids. Only plants and protists (bacteria, algae, fungi) are capable of synthesizing carotenoids. Therefore astaxanthin must be available in either their native habitat or manufactured diet to meet metabolic nutritional requirements. In the natural aquatic environment, astaxanthin is biosynthesized in the food chain within microalgae or phytoplankton. A micro-algae called Haematococcus pluvialis is believed to be the organism which can accumulate the highest levels of astaxanthin in nature.^{7 8}

Astaxanthin can be found in many of our favorite seafoods such as salmon, trout, red seabream, shrimp, and fish eggs.²Therefore, including these foods in your diet will increase your intake of this powerhouse antioxidant. There are two forms of astaxanthin, free and esterified. The esterified seems to be more stable and is believed to be an adaptive feature to allow storage of astaxanthin in tissues.⁹

Astaxanthin Sources Mixed Free and Esterified

• Sockeye salmon (26-37 mg/kg)
• Coho salmon (9-21 mg/kg)
• Chum salmon (3-8 mg/kg)
• Chinook salmon (8-9 mg/kg)
• Pink salmon (4-6 mg/kg)
• Atlantic salmon (3-11 mg) Rainbow trout (1-3 mg/kg)
• Synthetic astaxanthin (80,000 mg/kg – fed to farmed animals;100% free form)

Astaxanthin Sources – Predominantly Esterified

• Salmon eggs (0-14 mg/kg)
• Red seabream (2-14 mg/kg) Red seabream eggs (3-8 mg/kg)
• Peneaus monodon (10-150 mg/kg)
• Krill (46-130 mg/kg) Krill oil (727 mg/kg)
• Crayfish meal (137 mg/kg)
• Artic shrimp (1160 mg/kg)
• Yeast (Pfaffia r.) (30-800 mg/kg)
• Haematococcus pluvialis (10,000-30,000 mg/kg)

A few companies are beginning to manufacture astaxanthin in supplement form. Most of the recent development involves the micro-algae Haematococcus pluvialis. Remember, consume a variety of seafood to naturally increase your consumption of this powerhouse antioxidant.