Astaxanthin is a potent antioxidant that helps prevent sun damage to the body by blocking free radical damage. This bright red molecule forms in certain algae, pink seafood, and yeast. Unlike beta-carotene, this carotenoid crosses the blood-brain barrier to help maintain healthy brain function. Astaxanthin helps the brain by promoting neurogenesis, the generation of new brain neurons. This nutrient also supports existing neurons by reducing oxidative stress. Scientists have found that astaxanthin can protect against cumulative sun damage to the eye. This nutrient may help reduce the risk of eye disease such as macular degeneration. It may also protect against cataracts and vision loss from glaucoma. In addition, related carotenoids called lutein and zeaxanthin block blue light and work synergistically with astaxanthin.
Astaxanthin also boosts the immune system, and has certain anti-cancer properties.
Why is Sun Damage a Problem?
The sun releases both blue light and ultraviolet radiation. Since humans evolved on earth, why is sun damage a problem for us? We have some built-in mechanisms, but they are not quite enough.
Humans were originally adapted to raise their children to breeding age. We now live double or triple 30 years. Damage from sun exposure is cumulative.
Melanin in the skin increases on exposure to the sun. This dark pigment provides natural protection from UV light. The lighter your skin, the more susceptible you are to sun damage.
Melanin in the pupil helps protect the eye from sunlight. The darker the eye color, the more protection. Blue eyes and pink/red-looking albino eyes are most susceptible.
Some theorize that cataracts may be the body’s last-ditch attempt to protect the macula from free radical damage. Acting as internal sunglasses, cataracts grow slowly and provide sun protection. Unfortunately, cataracts also reduce clear vision, and can ultimately result in blindness unless treated when they get to a mature or ripened stage.
The Industrial Revolution led to a damaged ozone layer in our atmosphere. The ozone layer provides significant protection from sun damage. Phasing out chlorofluorocarbons (CFCs) helped, but not before increasing the rates of skin cancer, macular degeneration, and cataracts. The full effects of phasing out CFCs may not be felt for another 30 years.
Why Algae Doesn’t Get Sunburned
Algae grow well in sunny waters. However, too much sun damages human eyes and skin. Scientists have shown that ultraviolet radiation creates free radicals. Desperately needing an electron, free radicals steal them from healthy cells. When the free radicals take an electron from a healthy cell, it damages the cell and the DNA. Ongoing exposure to sunlight also speeds up activity in the retina. This creates additional waste and free radicals, putting extra stress on the body.
Why isn’t sun damage a problem for algae? Algae contain the carotenoid astaxanthin. Astaxanthin is a potent antioxidant. It is 50 times more potent than Vitamin E and 500 more potent than Vitamin C in neutralizing free radicals. Protected from ultraviolet radiation, algae get their energy directly from the sun through photosynthesis. They are at the bottom of the food chain, providing nourishment to many species.
How to Prevent Sun Damage
The good news about sun damage is that you have control over most of your sun exposure. Whenever you are outside, wear protective clothing and accessories, such as:
- Sunglasses that offer full UVA and UVB protection (halts UV exposure). Amber colored lenses neutralize blue light as well.
- Sunscreen, applied and re-applied according to package directions (do not apply to eyelids–use sunglasses instead)
- A wide-brimmed hat (reduces UV exposure by 30%)
- UV-protected swimwear, beachwear, and sportswear
The sun is strongest between 10 AM and 2 PM. Seek shade during those times, especially around noon.
Scientists are learning that astaxanthin may protect people from sun damage. While astaxanthin is in certain foods, we can get a therapeutic dose from supplements.
Research on Astaxanthin and Free Radical Damage
We find astaxanthin in pink seafood such as salmon, krill, crab, shrimp, crayfish, lobster, and trout. They get astaxanthin from eating a microalgae, Haematococcus pluvialis. Farmed salmon may have much less astaxanthin than wild salmon.1 Astaxanthin is also found in a yeast species called Xanthophyllomyces dendrorhous (Phaffia). Supplements for humans are usually made from microalgae or yeast. Krill oil is another supplemental source.
Astaxanthin is credited with supporting macular degeneration, heart health, gastric ulcers, cancer, acid reflux, arthritis, and sunburn. As one of the most powerful antioxidants, this substance reduces inflammation and oxidative stress.
The blood-brain barrier protects the brain and other neural tissue from unwanted chemicals. Astaxanthin crosses the blood-brain barrier. The eye’s retina is neural tissue. Therefore, astaxanthin can reach the eye directly.
For such a small organ, the eye is nutrient-hungry. Its tiny structures are highly susceptible to free radical damage from the sun and other sources. Scientists are further researching the effects of astaxanthin on the brain, as well as on the eye diseases macular degeneration, glaucoma, and cataracts.
Research on Astaxanthin and the Brain
One study gave human subjects 6mg to 12mg of astaxanthin per day for 12 weeks.2 This was a well-designed study on 96 middle- to senior-aged who had age-related memory loss. The researchers found that the people who took either amount of this antioxidant had significant improvements in the Groton Maze Learning Test (related to improved reaction time). Those who took 12mg also had faster reaction times.
An animal study focused on the hippocampus and spatial memory. The scientists carefully dissected the brains of rodents who had taken astaxanthin. They found that these mice had better spatial memory and an improved hippocampus. 3
Another study examined mouse brain cells in the laboratory. First, the cells were exposed to astaxanthin for 8 hours. Then, they were treated with hydrogen peroxide, which causes oxidization. When the cells were cultivated, they were more resistant to oxidization.4
Research on Astaxanthin and the Eyes
Astaxanthin appeared to reduce damage to the retina from elevated intraocular pressure.5 This study on rats may point to treatments for glaucoma.
Cataract formation may be inhibited by astaxanthin.6 This study, published in Experimental Dermatology, looked at human lens cells. The study verified that astaxanthin protects the lens from fat oxidation, which is triggered by UV exposure.
Macular degeneration is a retinal disease that damages central vision. Free radical damage to the center of the retina is suspected of playing a major role.7 Experimenting on retinal cells in the lab, researchers found that astaxanthin protected the cells from oxidative stress.8
Two More Special Eye Nutrients
- Mar Drugs. 2014 Jan; 12(1): 128–152. Published online 2014 Jan 7. doi: 10.3390/md12010128 PMCID: PMC3917265 PMID: 24402174 Astaxanthin: Sources, Extraction, Stability, Biological Activities and Its Commercial Applications—A Review, Ranga Rao Ambati et. al. ↩
- J Clin Biochem Nutr. 2012 Sep;51(2):102-7. doi: 10.3164/jcbn.D-11-00017. Epub 2012 Mar 30. Effects of astaxanthin-rich Haematococcus pluvialis extract on cognitive function: a randomised, double-blind, placebo-controlled study. By Katagiri M, Satoh A, Tsuji S, Shirasawa T ↩
- Mol Nutr Food Res. 2016 Mar;60(3):589-99. doi: 10.1002/mnfr.201500634. Epub 2016 Jan 7. Astaxanthin supplementation enhances adult hippocampal neurogenesis and spatial memory in mice. Yook et. al. ↩
- J Microbiol Biotechnol. 2009 Nov;19(11):1355-63. Astaxanthin inhibits H2O2-mediated apoptotic cell death in mouse neural progenitor cells via modulation of P38 and MEK signaling pathways. Kim JH et. al. ↩
- Cort A, Ozturk N, Akpinar D, et al. Suppressive effect of astaxanthin on retinal injury induced by elevated intraocular pressure. Regul Toxicol Pharmacol. 2010 Oct;58(1):121-30. ↩
- E. Camara, et al, Astaxanthin, canthaxanthin, and beta-carotene differently affect UVA-induced oxidative damage and expression of oxidative stress-responsive enzymes Experimental Dermatology, March, 2009. ↩
- Arch Ophthalmol. 2008 Oct;126(10):1396-403. doi: 10.1001/archopht.126.10.1396. Sunlight exposure, antioxidants, and age-related macular degeneration. Fletcher AE et al. ↩
- Int J Ophthalmol. 2019 Jun 18;12(6):930-935. doi: 10.18240/ijo.2019.06.08. eCollection 2019. Effects of astaxanthin on antioxidant parameters in ARPE-19 cells on oxidative stress model. Yigit M et al. ↩