Researchers flag lack of synthetic astaxanthin safety parameters, but green-light natural source

10 Dec 2019 --- Natural astaxanthin (AX), a carotenoid pigment found in some algae and increasingly popular in supplements, are safe in doses up to 24 mg per day. This is according to a safety review published in Phytotherapy Research. While recommended or approved doses in different countries currently range between 2-24 mg per day, the researchers reviewed 87 human studies, none of which found safety concerns with natural AX supplementation. However, the researchers are calling for further studies to be conducted with synthetic AX, noting it is necessary to establish a different acceptable daily intake (ADI) for the separate forms.

According to Innova Market Insights data, there has been an average annual growth of 18 percent of product launches tracked with AX between 2014 and 2018. Among the top ten health claims in products with AX are eye, skin, bone and muscle health, the market researcher notes.

AX enters the human diet through some varieties of fish and crustaceans, which ingest the algae. While commercial AX is generally sourced from H. pluvialis, some manufacturers are turning to synthetic forms due to the ecological issues surrounding krill harvesting and limitations on yields from cultivated algae.

“Although synthetically produced AX has only demonstrated species-specific effects at very high doses, it must be considered unique and should not be introduced for direct human use (in contrast to animal feed) until safety parameters are established and human clinical trials showing potential benefits have been conducted,” the researchers write.

The review examined the results of both short-term daily doses of up to 100 mg of AX and long-term daily doses averaging between 8-12 mg in over 2,000 participants. In addition to no severe adverse events being recorded, no indicators of liver toxicity (such as elevated enzymes) were reported in any clinical studies. However, reddening of stool is a minor adverse event occurring at high doses.

Currently, AX manufacturers in the EU are largely reliant on notifications issued on the basis of “substantial equivalence,” using previous products with doses of 2 mg as a guide. However, in 2018, the new Novel Foods Regulation came into force with an AX-rich oleoresin having a maximum ADI level for AX of up to 8 mg. 

Some manufacturers are turning to synthetic forms of AX.Meanwhile, the US Food and Drug Administration (FDA) is satisfied with the safety of AX derived from H. pluvialis and P. carotinifaciens at doses below 6-7 mg per day. In terms of new dietary ingredient notifications (NDINs), the FDA has had no objections to a variety of AX products over the last 20 years. These have a recommended daily dose ranging from 2-24 mg per day. 

A recent AstaReal webinar highlighted how the naturally occurring carotenoid not only taps into classic preventative aging categories such as heart and muscle health and vision, but also offers efficacy for newer categories.

Andie Long, Manager of Marketing and Sales at Astareal tells NutritionInsight that the company’s clinical database includes over 60 human clinical trials with over 1800 participants. “The doses used in these trials ranged from 2-45 mg per day. The trials were designed to determine the efficacy, safety, and tolerance of AstaReal AX for different doses, treatment periods, study designs and demographic variables. All studies revealed no adverse effects based on hematological findings, serum chemistry, urinal analysis and self-report questionnaires.”

By Katherine Durrell