Astaxanthin: Uses, Benefits, and Properties Explained
Astaxanthin is a carotenoid responsible for the red pigmentation in salmon and krill. It is the most stable carotenoid structure and a potent antioxidant with proven cardiovascular, brain, and immune system benefits. Many of its benefits come from its unique molecular structure, which we will discuss in this article.
Carotenoids are known to have benefits in human health for their health benefits to reduce disease – particularly eye diseases and certain cancers1. Some common carotenoids are beta-carotene, lycopene, and lutein. Carotenoids are comprised of two different types: xanthophyll or carotenes, which cannot be synthesized by humans and must come from diet from algae, plants, and fungi2. Carotenes do not possess an oxygen molecule, while xanthophylls possess one or several oxygen atoms in their molecular structure in the form of a hydroxyl (-OH) or ketone (=O) group. The difference between Carotenes and Xanthophylls can be seen in the figure below comparing beta-carotene (a carotene) with cryptoxanthin (a xanthophyll). Note that the only difference between these two structures are an oxygen atom in the form of a hydroxl (-OH) group.
Figure 1: The structural difference between Beta-Carotene (Carotene) and Cryptoxanthin (Xanthophyll) differs only by a hydroxyl (-OH) group.
Structure of Astaxanthin
Due to the many conjugated double bonds in each type of carotenoid, these compounds are very colorful: with carotene compounds generally being orange, and xanthophyll compounds generally being yellow. These conjugated double bonds are also the reason for the antioxidant properties of all carotenoids. Astaxanthin is unique in the class of xanthophylls because it contains both hydroxyl and ketone functional groups at each end of the structure.
Figure 2: The Structure of Astaxanthin
This makes astaxanthin lipophilic (fat soluble) in the center and hydrophilic (water soluble) at each end of the structure. This unique structure allows astaxanthin to position itself across a cell membrane, linking cell membrane from inside to outside. This superior positioning of astaxanthin results in better biological activity compared to other common antioxidants (such as vitamin c and beta-carotene)3.
Figure 3: Astaxanthin positions itself across a cell membrane, protecting the cell from the inside and outside
Since carotenoids are fat soluble, they are transported via the lympathic system into the liver. Due to this, carotenoids like astaxanthin are better absorbed when they are taken with a dietary fat source. After ingestion, astaxanthin mixes with bile acid and absorbed by intestinal mucosal cells. Astaxanthin is then assimilated with lipoproteins and transported into the tissues. Astaxanthin is considered one of the best carotenoids being able to protect cells, lipids, and membrane lipoproteins against oxidative damage4.
Astaxanthin as an Antioxidant
In terms of antioxidant protection, astaxanthin has proven itself to be the best; having been found to be 6000 times stronger than vitamin c, 800 times stronger than CoQ10, 550 times stronger than green tea catechins, and 75 times stronger than alpha-lipoic acid when it comes to singlet-oxygen quenching5. As discussed earlier, these very strong antioxidant effects of Astaxanthin come from its many conjugated double bonds in its structure, its keto and alcohol groups at each end of the structure, and its ability to span a cell membrane in order to protect a cell membrane from the inside and outside of the cell.
Astaxanthin and its Role in Heart Health, Blood Pressure, and Cholesterol
Since oxidative stress and inflammation are common pathophysiological features of atherosclerotic cardiovascular disease, astaxanthin would sound like a reasonable candidate for therapeutic benefit in protecting the heart from cardiovascular disease. In clinical studies assessing astaxanthin’s effects for atherosclerotic treatment, no adverse effects were reported and a reduction in biomarkers of oxidative stress and inflammation were seen with astaxanthin administration6.
Studies in several species such as dog, rat, and rabbit have demonstrated that astaxanthin protects the myocardium when administered orally or intravenously7. It has also been shown that consumption of beta-carotene is associated with a reduction in cardiovascular disease8. Though the amount of current human studies showing the relation of astaxanthin with prevention in cardiovascular disease are not plentiful due to astaxanthin being a newly studied compound - with astaxanthin having much more pronounced antioxidant and anti-inflammatory effects than beta carotene, we can expect it to be more effective.
In humans, use of astaxanthin reduced LDL by inhibiting LDL oxidation with doses between 14-21mg/day with no other change in diet9. Astaxanthin has also been shown in humans to increase HDL in several studies10 as well as improving glucose metabolism and triglycerides. In one study, 61 subjects used doses of 6-18mg/day of astaxanthin for 12 weeks and saw a significant decease in triglycerides and a significant increase in HDL. Adinopectin, a protein hormone involved in regulating glucose levels, also showed significant increase in the groups using 12 and 18mg/day astaxanthin11. In addition, astaxanthin shows promise in reducing high blood pressure by modulating nitric oxide and relaxing the blood vessels12.
Neuroprotective Effects of Astaxanthin
As interest in this compound continues to develop over the past few years, astaxanthin continues to be researched across different disease models. As an antioxidant, anti inflammatory, anti apoptic, and potential to promote or maintain neural plasticity, astaxanthin shows promise in exerting strong neuroprotective effects. Astaxanthin promotes activity of antioxidant enzymes, maintaining function of these enzymes has important contribution to normal aging, neurodegenerative diseases, and brain injury13.
Astaxanthin and Anti-Diabetic Activity
In addition to increasing adinopectin levels, astaxanthin has been shown to reduce hyperglycemia-induced oxidative stress in pancreatic beta-cells and improve glucose and serum insulin levels16.
Astaxanthin and Eye Health
Astaxanthin’s antioxidant effect has also been shown to be beneficial in improved eye health, and treatment of retinal ischemia18 – a condition where blood flow is reduced to the eye.
Astaxanthin and Skin Health
Skin health declines over time due to UV damage, damage to DNA, reduced antioxidant production, inflammatory response, and collagen and elastin degredation. Again, here is where astaxanthin’s potent antioxidant and anti-inflammatory effects help to reduce skin damage, repair DNA, and enhance the immune system17.
Natural vs Synthetic Astaxanthin
Due to being a common additive in animal diets, nearly 95% of astaxanthin is mass produced synthetically for cost efficiency. However, the increased demand for human consumption is creating a need for more naturally produced astaxanthin, since synthetic astaxanthin has shown safety issues in humans14 and natural astaxanthin may be up to 3x more potent in antioxidant activity than synthetic15. Natural astaxanthin is produced from algae, yeast, and crustacean byproduct.
Summary of Astaxanthin
To summarize, astaxanthin is rather new to the world of dietary supplements, but has shown to be one of the strongest antioxidants available (6000x stronger than vitamin C) due to its unique structure and ability to position itself across the cell membrane in order to protect the cell. Astaxanthin also has documented human use showing its effectiveness at increasing HDL and adinopectin, while decreasing LDL and triglycerides. Astaxanthin has neuroprotective benefits as well as skin and eye benefits. Leviathan IRE, our complete health optimization supplement, features the high-end clinical dose of 18mg of natural astaxanthin produced from algae (Haematococcus pluvialis) per serving in order to fully gain these benefits.