Spirulina (dietary supplement)
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A. maxima |
Spirulina is the common name for human and animal food supplements produced primarily from two species of cyanobacteria: Arthrospira platensis, and Arthrospira maxima. These and other Arthrospira species were once classified in the genus Spirulina. There is now agreement that they are distinct genera, and that the food species belong to Arthrospira; nonetheless, the inaccurate term "Spirulina" remains the popular name. Spirulina is cultivated around the world, and is used as a human dietary supplement, available in tablet, flake, and powder form. It is also used as a feed supplement in the aquaculture, aquarium, and poultry industries.[1]
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[edit] Biology
Spirulina are free-floating filamentous cyanobacteria characterized by cylindrical, multicellular trichomes in an open left-hand helix. Spirulina occurs naturally in tropical and subtropical lakes with high pH and high concentrations of carbonate and bicarbonate. A. platensis occurs in Africa, Asia and South America, whereas A. maxima is confined to Central America.[1]
[edit] History
Spirulina is believed to have been a food source for the Aztecs in 16th century New Spain (part of which is now Mexico), as its harvesting from Lake Texcoco and sale as cakes is described by one of Cortés' soldiers.[2] The Aztecs called it Tecuitlatl, meaning stone's excrement. Spirulina was found in abundance at the lake by French researchers in the 1960s, but there is no reference to its use there as a daily food source after the 16th century. The first large-scale Spirulina production plant, run by Sosa Texcoco, was established there in the early 1970s.[1]
Spirulina may have an even longer history in Chad, as far back as the 9th century Kanem Empire. It is still in daily use today, dried into cakes called Dihé which are used to make broths for meals, and also sold in markets. The Spirulina is harvested from small lakes and ponds around Lake Chad.[3]
[edit] Cultivation
Most cultivated spirulina is produced in open-channel raceway ponds, with paddle-wheels used to agitate the water. The largest commercial producers of spirulina are located in the United States, Thailand, India, Taiwan, China, and Myanmar.[1]
Spirulina has been proposed by both NASA (CELSS)[4] and the European Space Agency (MELISSA)[5] as one of the primary foods to be cultivated during long-term space missions. Spirulina is used for making healthy drinks with water only or with water and honey.
[edit] Nutrients and other chemicals
[edit] Protein
Spirulina contains unusually high amounts of protein, between 55 and 77% by dry weight, depending upon the source. It is a complete protein, containing all essential amino acids, though with reduced amounts of methionine, cysteine, and lysine, as compared to standard proteins such as that from meat, eggs, or milk. It is, however, superior to all standard plant protein, such as that from legumes.[6][7]
[edit] Essential Fatty Acids
Spirulina is rich in gamma-linolenic acid (GLA), and also provides alpha-linolenic acid (ALA), linoleic acid (LA), stearidonic acid (SDA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA).[7][8]
[edit] Vitamins
Spirulina contains vitamin B1 (thiamine), B2 (riboflavin), B3 (nicotinamide), B6 (pyridoxine), B9 (folic acid), B12 (cyanocobalamin), vitamin C, vitamin D, and vitamin E.[7][8] The bioavailability of vitamin B12 in Spirulina is in dispute. Several biological assays have been used to test for the presence of vitamin B12.[9] The most popular is the US Pharmacopeia method using the Lactobacillus leichmannii assay. Studies using this method have shown Spirulina to be a minimal source of bioavailable vitamin B12.[10] However, this assay does not differentiate between true B12 (cobalamin) and similar compounds (corrinoids) that cannot be used in human metabolism. Cyanotech, a grower of spirulina, claims to have done a more recent assay, which has shown Spirulina to be a significant source of cobalamin. However the assay is not published for scientific review and so the existence of this assay is in doubt.[11]
[edit] Minerals
Spirulina is a rich source of potassium, and also contains calcium, chromium, copper, iron, magnesium, manganese, phosphorus, selenium, sodium, and zinc.[7][8]
[edit] Photosynthetic Pigments
Spirulina contains many pigments including chlorophyll-a, xanthophyll, beta-carotene, echinenone, myxoxanthophyll, zeaxanthin, canthaxanthin, diatoxanthin, 3'-hydroxyechinenone, beta-cryptoxanthin, oscillaxanthin, plus the phycobiliproteins c-phycocyanin and allophycocyanin.[1]
[edit] Evidence of health and healing effects
Advocates frequently overstate their claims of Spirulina's health and healing properties, though often there is research upon which such claims are based. Conversely, health food detractors often dismiss all such claims without acknowledging existing research. Two online publications exemplify these opposing positions, respectively: Superfoods For Optimum Health: Chlorella and Spirulina, and Wellness Letter on Blue Green Algae. Many positive claims are based on research done on individual nutrients that Spirulina contains, such as GLA, various antioxidants, etc., rather than on direct research using Spirulina. What follows is research on the health and healing effects of Spirulina. In vitro research may suggest the possibility of similar results in humans, but cannot be taken as proof of human effects. Animal research provides stronger evidence, but again, does not represent proof of similar effects in humans. The results of Clinical trials are the best evidence available.
In vitro research
Spirulina extract inhibits HIV replication in human T-cells, peripheral blood mononuclear cells (PBMC), and Langerhans cells.[12]
Animal research
Spirulina helps prevent heart damage caused by chemotherapy using Doxorubicin, without interfering with its anti-tumor activity.[13] Spirulina reduces the severity of strokes and improves recovery of movement after a stroke;[14] reverses age-related declines in memory and learning;[15] and prevents and treats hay fever.[16]
Clinical trials
Spirulina is effective for the clinical improvement of melanosis and keratosis due to chronic arsenic poisoning;[17] improves weight-gain and corrects anemia in both HIV-infected and HIV-negative undernourished children;[18] and protects against hay fever.[19]
[edit] Allergic Reactions
There are reported allergic reactions to spirulina. Symptoms include dry fevers and nausea. In such instances inducing vomiting to quell the symptoms and contacting medical services is recommended.[citation needed]
[edit] References
- ^ a b c d e Vonshak, A. (ed.). Spirulina platensis (Arthrospira): Physiology, Cell-biology and Biotechnology. London: Taylor & Francis, 1997.
- ^ Diaz Del Castillo, B. The Discovery and Conquest of Mexico, 1517-1521. London: Routledge, 1928, p. 300.
- ^ Abdulqader, G., Barsanti, L., Tredici, M. "Harvest of Arthrospira platensis from Lake Kossorom (Chad) and its household usage among the Kanembu." Journal of Applied Phychology. 12: 493-498. 2000.
- ^ Characterization of Spirulina biomass for CELSS diet potential. Normal, Al.: Alabama A&M University, 1988.
- ^ Cornet J.F., Dubertret G. "The cyanobacterium Spirulina in the photosynthetic compartment of the MELISSA artificial ecosystem." Workshop on artificial ecological systems, DARA-CNES, Marseille, France, October 24-26, 1990
- ^ Ciferri, O. "Spirulina, the Edible Microorganism." Microbiological Reviews. 47, 4, Dec. 1983.
- ^ a b c d Babadzhanov, A.S., et al. "Chemical Composition of Spirulina Platensis Cultivated in Uzbekistan." Chemistry of Natural Compounds. 40, 3, 2004.
- ^ a b c Tokusoglu, O., Unal, M.K. "Biomass Nutrient Profiles of Three Microalgae: Spirulina platensis, Chlorella vulgaris, and Isochrisis galbana." Journal of Food Science. 68, 4, 2003.
- ^ Variations in the Growth Response of Four Different Vitamin B12 Assay Microorganisms to the Same Tissue and Standard Preparations. Elizabeth A. Cook and Lillian N. Ellis. Appl Microbiol. 1968 December; 16(12): 1831–1840.
- ^ Watanabe, F. et al. "Characterization and bioavailability of vitamin B12-compounds from edible algae." Journal of nutritional science and vitaminology, Oct. 2002, 48 (5):325-331.
- ^ Spirulina Pacifica® as a Source of Cobalamin Vitamin B-12. Jan. 1999.
- ^ Ayehunie, S. et al. "Inhibition of HIV-1 Replication by an Aqueous Extract of Spirulina platensis (Arthrospira platensis)." JAIDS: Journal of Acquired Immune Deficiency Syndromes & Human Retrovirology. 18, 1, May 1998: 7-12.
- ^ Khan, M., et al. "Protective effect of Spirulina against doxorubicin-induced cardiotoxicity." Phytotherapy Research. 2005 Dec;19(12):1030-7.
- ^ Wang, Y., et al. "Dietary supplementation with blueberries, spinach, or spirulina reduces ischemic brain damage." Experimental Neurology. May, 2005 ;193(1):75-84.
- ^ Gemma, C., et al. "Diets enriched in foods with high antioxidant activity reverse age-induced decreases in cerebellar beta-adrenergic function and increases in proinflammatory cytokines." Experimental Neurology. July 15, 2002; 22(14):6114-20.
- ^ Chen, LL, et al. "Experimental study of spirulina platensis in treating allergic rhinitis in rats." 中南大学学报(医学版) = Journal of Central South University (Medical Sciences). Feb. 2005. 30(1):96-8.
- ^ Mir Misbahuddin, AZM Maidul Islam, Salamat Khandker, Ifthaker-Al-Mahmud, Nazrul Islam and Anjumanara. Efficacy of spirulina extract plus zinc in patients of chronic arsenic poisoning: a randomized placebo-controlled study. (Risk factors ). Journal of Toxicology: Clinical Toxicology. 44.2 (March 2006): p135(7).
- ^ Simpore, J., et al. "Nutrition Rehabilitation of HIV-Infected and HIV-Negative Undernourished Children Utilizing Spirulina." Annals of Nutrition & Metabolism. 49, 2005: 373-380.
- ^ Mao, TK, et al. "Effects of a Spirulina-based dietary supplement on cytokine production from allergic rhinitis patients." Journal of Medicinal Food. Spring 2005;8(1):27-30.
