Scientific discoveries 27/07/2020
The three sources of astaxanthin: which one should you choose?
Astaxanthin is considered as being one of the most powerful antioxidants, due to its capacity for protecting the entire cell. It is believed to have a variety of health care benefits: skin protection, ocular health, athletic performance, a healthy heart and improved fertility. Its benefits have been extensively studied in scientific literature, and are now confirmed. However, the origins have never been very clear: are the benefits derived from astaxanthin from natural sources? Or from synthetic astaxanthin? Or even from astaxanthin produced from yeast?
There are many questions regarding the sources of astaxanthin. And these questions are even more important when choosing a dietary supplement. Let’s take a look at recent research published by Capelli, Tallbott and Ding.
Choosing the most suitable astaxanthin using science
Published in 2019 in the scientific journal Functional Foods in Health and Disease, the research carried out by Capelli B., Talbott S. and Ding L. is a compilation of literature on astaxanthin [1]. It covers the 3 sources of astaxanthin, their chemical and antioxidant differences and health care benefits. This scientific research helps us to better understand the origins of this antioxidant and choose the right source.
Astaxanthin and its three sources
This research has identified three forms of astaxanthin, derived from different sources.
- Natural astaxanthin is usually extracted from Haematococcus pluvialis. Haematococcus pluvialis is a unicellular microalgae that grows in fresh water and contains the greatest quantities of astaxanthin.
- Synthetic astaxanthin is produced from petrochemical products.
- Phaffia astaxanthin is extracted from the yeast Xanthophyllomyces dendrorhous (Phaffia rhdozyma). This yeast, which naturally produces very small quantities of astaxanthin, has been genetically modified to exponentially produce the antioxidant.
Research results: which source should you choose and why?
The three forms of astaxanthin show differences on a chemical level, in terms of antioxidant activity and in health care benefits.
Chemical differences
Natural, synthetic and Phaffia astaxanthin have different molecular formulas and compositions.
Their molecular formulas have different forms (see figure below). These forms are referred to as enantiomers: "S" enantiomer (3S,3'S), "R” enantiomer (3R,3'R) and "meso" enantiomer (3R,3'S). Natural astaxanthin contains only "S" enantiomer (3S,3'S). Synthetic astaxanthin contains a variety of the three enantiomers. Phaffia astaxanthin contains only "R” enantiomer (3R,3'R).
In terms of the difference in composition, two points are worth mentioning. Firstly, natural astaxanthin is composed of 95.7 % esterified molecules, which is not the case for synthetic and Phaffia astaxanthin, which are “free”, i.e. non-esterified. Secondly, synthetic and Phaffia astaxanthin do not contain carotenoids other than astaxanthin. Conversely, natural astaxanthin is composed of other carotenoids, such as cantaxanthin, beta-carotene, zeaxanthin and lutein.
Differences in antioxidant activity
In addition to chemical differences, the authors also discovered dissimilarities in the level of antioxidant activity in the different forms of astaxanthin. After conducting two in vitro studies, they were able to confirm that natural astaxanthin has a higher level of antioxidant activity than synthetic astaxanthin.
The first study, published in 2013, showed that natural astaxanthin is at least 14 times more powerful than synthetic astaxanthin in terms of antioxidant activity [2]. Moreover, this study also tested the effects of astaxanthin on five free radicals found in the human body. The results showed that natural astaxanthin was more active in eliminating singlet oxygen (up to 55 times more active), the superoxide ion and peroxyl radicals, whereas synthetic astaxanthin proved to be more active on peroxynitrite [2].
The second study, published in 2015, highlighted the superior antioxidant capacity of natural astaxanthin [3]. In this study, the researchers tested and compared two natural forms of astaxanthin with a synthetic astaxanthin. The two natural forms showed antioxidant activity that was approximately 90 times higher than that of synthetic astaxanthin [3].
As for comparisons with Phaffia astaxanthin, the researchers were not aware of any studies comparing Phaffia astaxanthin with other forms. Nonetheless, as Phaffia astaxanthin is chemically similar to synthetic astaxanthin, they estimated that natural astaxanthin would also have superior antioxidant activity compared to Phaffia.
Product safety and side effects
Product safety: another important aspect highlighted in the research study by Capelli, Talbott et Ding. Once again, the three forms of astaxanthin are different.
In several clinical trials, natural astaxanthin proved to be safe for consumption and had a wide variety of health care benefits. In addition, for over 20 years, it has been consumed as a dietary supplement, with no adverse side effects.
However, synthetic and Phaffia astaxanthin have not been proven safe for human consumption through clinical trials. This is why they have not been authorized by government regulatory agencies in many countries.
Conclusion: what source of astaxanthin should you choose?
Based on this study, natural astaxanthin seems to be the best choice for your dietary supplements.
The research conducted by Capelli, Talbott and Ding has highlighted the superior antioxidant activity and safety of natural astaxanthin. Until the effectiveness and safety of synthetic and Phaffia astaxanthin are proven, the authors recommend natural astaxanthin as a source for dietary supplements.
Sources
[1] Capelli B, Talbott S, and Ding L. "Astaxanthin sources: Suitability for human health and nutrition." Functional Foods in Health and Disease9.6 (2019): 430-445
