We’re talking about astaxanthin, the antioxidant touted in the online article, Astaxanthin: A Rising Star in Alzheimer’s Prevention, Among antioxidants, astaxanthin does appear to have some unique characteristics.
Tiny photosynthetic organisms found in marine environments—microalgae and phytoplankton, synthesize it. The richest natural source is the microalgae Haematococcus pluvialis. In addition, Roche pharmaceutical company began large-scale production of synthetic astaxanthin in 1990 (Ref. 3).
It appears that astaxanthin from H. pluvialis has high bioavailability, meaning it is well absorbed by the body. There is evidence (in rats) that it can protect living cells from damage by free radicals (Ref. 3). In vitro (in a test tube… literally in glass), astaxanthin has ten times higher antioxidant activity than other carotenoids, and 100 times higher antioxidant activity than vitamin E (Ref. 3).
Astaxanthin from H. pluvialis seems to be safe. A 2008 clinical study using astaxanthin to treat indigestion showed that 40 mg per day of H. pluvialis astaxanthin did not show any harmful effects during a 4-wk treatment period (Ref. 4). The original article cites a 2011 study that used 6 or 12 mg of astaxanthin for 12 weeks. I did not find any studies looking at longer than a 12-week period.
In the 12-week study, the researchers concluded that “concentrations of erythrocyte and plasma astaxanthin were not different between the 6 and 12 mg astaxanthin groups, suggesting that 6 mg astaxanthin is effective enough to show antioxidative benefit in vivo.” Those researchers were looking at decreases in markers for oxidative damage (the PLOOH mentioned in the original article) found in red blood cells and blood plasma (Ref. 7).
The same researchers have undertaken a new study testing daily doses from 3 to 6 mg of astaxanthin. Their concern is to find the lowest effective dosage. Finding the lowest effective dose is important, because when dealing with bioactive molecules, more is NOT necessarily better.
Numerous studies have shown that astaxanthin protects neuronal cells in rats and mice from oxidative damage. When researchers took neuron-like cells from a human cell line (human cells, often derived originally from cancers or tumors, that have been raised artificially for many years and many generations in laboratories) and exposed them to oxidative damage that would normally cause cell death, astaxanthin treatment was able to reduce the number of cells that died. (Refs. 5 and 6) The cells in this study were dopaminergic, which means that they use the neurotransmitter dopamine, similar to the cells that die in Parkinson’s disease.
Does that mean astaxanthin could help stop cell death in Parkinson’s? Maybe, but only if those cells are dying for the same reason as the cells in the study. You see, all we can ever do, prior to clinical testing results, is make an educated guess about what a supplement will or won’t do in humans.
And so far, clinical antioxidant studies looking for memory effects have not been too promising. They have found that vitamin E does not significantly slow down memory decline for Alzheimer’s patients or early Parkinson’s patients. Furthermore, a combination of vitamins E and C did not significantly improve college students’ performance on specific cognitive tasks. I was unable to access the “small clinical trial” that found astaxanthin “improved cognition.” I hope to remedy that problem before my next post.
Astaxanthin looks like a good antioxidant. It has extremely high antioxidant activity. It looks like it is probably safe. And it appears that the best source is H. pluvialis.
Would I spend a lot of money on one specific antioxidant supplement? No, not a lot of money. But if it was reasonably priced I might add one to my diet. Still, I always prefer real food to pills! And with real food, I know my body has been designed to do a good job of absorbing the nutrients (and antioxidants) I ingest.
The next section of the article goes into other avenues, some of which have been clearly shown to enhance brain health. More on that next time.
1) Eric A. Johnson and Gil-Hwan An, Astaxanthin from Microbial Sources, Critical Reviews in Biotechnology, 1991, Vol. 11, No. 4, pages 297-326.
2) Paola Palozza and Norman I. Krinsky, Astaxanthin and canthaxanthin are potent antioxidants in a membrane model, Archives of Biochemistry and Biophysics, 1992, Vol. 297, Issue 2, pages 291-295.
3) Jian-Ping Yuan, Juan Peng, Kai Yin and Jiang-Hai Wang, Potential health-promoting effects of astaxanthin: A high-value carotenoid mostly from microalgae, Mol. Nutr. Food Res.,2011, Vol. 55, pages150–165.
4) Kupcinskas, L., Lafolie, P., Lignell, A, Kiudelis, G. et al., Efficacy of the natural antioxidant astaxanthin in the treatment of functional dyspepsia in patients with or without Helicobacter pylori infection: a prospective, randomized, double blind, and placebo-controlled study, Phytomedicine,2008, Vol. 15, pages 391–399.
5) Ikeda, Y., Tsuji, S., Satoh, A., Ishikura, M. et al., Protective effects of astaxanthin on 6-hydroxydopamine-induced apoptosis in human neuroblastoma SH-SY5Y cells, J. Neurochem., 2008, Vol. 107,pages 1730–1740.
6) Liu, X. B., Shibata, T., Hisaka, S., Osawa, T., Astaxanthin inhibits reactive oxygen species-mediated cellular toxicity in dopaminergic SH-SY5Y cells via mitochondria-targeted protective mechanism, Brain Research, 2009, Vol. 1254,pages 18–27.
7) Kiyotaka Nakagawa, Takehiro Kiko, Taiki Miyazawa, Gregor Carpentero Burdeos, Fumiko Kimura, Akira Satoh and Teruo Miyazawa, Antioxidant effect of astaxanthin on phospholipid peroxidation in human erythrocytes, British Journal of Nutrition, 2011, Vol. 105, pages 1563–1571.