The distinct differences between natural and synthetic astaxanthin
• Synthetic astaxanthin is not made for human consumption. It is synthesized from petrochemicals and sold into animal-feed markets. Farm-raised salmon, for instance, generally are fed the far-less-expensive synthetic astaxanthin to color their flesh a more attractive reddish hue – otherwise they would be a pale gray, not attractive to consumers. When you are eating farm-raised salmon, you are also ingesting synthetic astaxanthin, even though it is not currently registered as a human food or supplement ingredient in any country.
• Natural astaxanthin, on the other hand, gives wild salmon their color.
• Synthetic astaxanthin is manufactured in a laboratory from petrochemicals or petrochemical derivatives.
• Natural astaxanthin is biosynthesized by living green microalgae (Haematococcus Pluvialis).
• Nearly all the studies demonstrating astaxanthin’s powerful health benefits for humans were conducted using natural astaxanthin.
• Synthetic astaxanthin is used as a feed supplement for salmon, crabs, shrimp, chickens and egg production.
Astaxanthin from Phaffia rhodozyma yeast
Astaxanthin also can be derived from mutated strains of Phaffia rhodozyma yeast, though its chemical structure is completely different than natural astaxanthin. Producers use UV light, gamma radiation or mutagenic chemicals to produce the mutations. It is used in trout and salmon feeds, but is not allowed for human consumption in some nations. The United States has placed serious restrictions on its use, such as allowing doses only up to 2 mg per day and disallowing its use for children.
What is esterified astaxanthin?
Astaxanthin that is ingested by marine animals such as krill, shrimp, wild salmon and lobsters is nearly always esterified, meaning that it has one or more fatty-acid molecules attached to it, as does natural astaxanthin from Haematococcus microalgae.
Astaxanthin from Phaffia rhodozyma is non-esterified, as is synthetic astaxanthin. Natural astaxanthin is always paired with fatty acids attached to the end of the fatty acid molecule, which results in an esterified molecule. Esterified astaxanthin has been shown to have greater stability and greater biological function than the non-esterified forms found in synthetic and Phaffia-derived astaxanthin, which is called “free” astaxanthin.
Sources of astaxanthin
Natural astaxanthin is cultivated at an industrial scale for human supplementation by several companies, including Cyanotech of Hawaii (BioAstin), Fuji Health Science of Japan (AstaREAL), and AlgaTech of Israel. As we have said elsewhere, it is also available in certain foods and dietary supplements, including krill oil and salmon oil. Some fish oil manufacturers also are beginning to add astaxanthin to their products.
Let’s compare the various sources of natural astaxanthin.
Astaxanthin Sources and Comparisons
Amount of Astaxanthin (per kg)
Source: Maher TJ. Astaxanthin: Continuing Education Module. New Hope Institute of Retailing, unpublished results, August 2000.