Spirulina is a human and animal food or nutritional supplement made primarily from two species of cyanobacteria: Arthrospira platensis and Arthrospira maxima.
Spirulina – cyanobacteria has been used as food for centuries by different populations and only rediscovered in recent years. It grows naturally in the alkaline waters of lakes in warm regions. It exists in the form of tiny green filaments coiled in spirals of varying tightness and number, depending on the strain. A number of features from the nutritional standpoint have been demonstrated: a balanced protein composition, and the presence of rare essential lipids, numerous minerals and even vitamin B12.
The cell walls of spirulina are similar to that of Gram-positive bacteria, since they consist of glucosamines and muramic acid associated with peptides. Although not digestible, these walls are fragile and make the cell content readily accessible to digestive enzymes. This is a major advantage in comparison to organisms with cellulosic cell walls like yeast and chlorella.
Algae Strains that produce Spirulina
Arthrospira platensis and Arthrospira maxima
Growth Conditions of Arthrospira platensis and Arthrospira maxima
Alkaline, brackish water
The optimum temperature for growth is 35°C, but above 38°C spirulina is in danger. Growth only takes place in light (photosynthesis), but illumination 24 hours a day is not recommended. During dark periods, chemical reactions take place within spirulina, like synthesis of proteins and respiration. Respiration decreases the mass of spirulina biomass ; its rate is much greater at high temperature so cool nights are better on that account, but in the morning beware that spirulina cannot stand a strong light when cold (below 15°C).
Spirulina thrives in alkaline, brackish water. Any water-tight, open container can be used to grow spirulina, provided it will resist corrosion and be non-toxic.
Composition of Spirulina
Spirulina contains about 60% (51–71%) protein of its dry weight. The protein content varies by 10-15% according to the time of harvesting in relation to daylight. Spirulina contain about 15-25% carbohydrates (dry weight). Spirulina is not considered to be a reliable source of Vitamin B12. The standard B12 assay, using Lactobacillus leichmannii, shows spirulina to be a minimal source of bioavailable vitamin B12. In strains of spirulina used, the nucleic acid levels vary from 4.2-6% of dry matter.
Spirulina's lipid content is about 7% by weight, and 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). Spirulina contains vitamins B1, B2 , B3 , B6 , B9 , vitamin C, vitamin D, vitamin A and vitamin E. It is also a source of potassium, calcium, chromium, copper, iron, magnesium, manganese, phosphorus, selenium, sodium and zinc. Spirulina contains many pigments which may be beneficial and bioavailable, including beta-carotene, zeaxanthin, chlorophyll-a, xanthophylls, echinenone, myxoxanthophyll, canthaxanthin, diatocanthin, 3’-hydroxyechinenone, beta-cryptoxanthin and oscillaxanthin, plus the phycobiliproteins c-phycocyanin and allophycocyanin.
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, Pakistan, Burma (a.k.a. Myanmar) and Chile.
Spirulina is a filamentous algae (meaning that it grows in strands), a shape that allows for harvesting by stainless steel screens. This method uses far less energy that centrifugation (which is used for chlorella, another microalgae) and is gentle on the cells.
While the spirulina is being sieved out on screens it is given several fresh water washes, ensuring a clean product with a fresh taste. Ponds are harvested to half of their depth, with what remains being the seed for the next generation. It is like mowing the lawn – part left behind grows again.
When the spirulina is in good condition, separating it from the water ("harvesting") is an easy operation, but when it gets too old and "sticky" harvesting may become a nightmare.
The best time for harvesting is early morning for various reasons :
- the cool temperature makes the work easier,
- more sunshine hours will be available to dry the product,
- the % proteins in the spirulina is highest in the morning.
There are basically two steps in harvesting :
- filtration to obtain a "biomass" containing about 10 % dry matter (1 liter = 100 g dry) and 50 % residual culture medium. Filtration is simply accomplished by passing the culture through a fine weave cloth, using gravity as the driving force.
- removal of the residual culture medium to obtain the "fresh spirulina biomass", ready to be consumed or dried, containing about 20 % dry matter and practically no residual culture medium.
Applications and Health Benefits of Spirulina
The nutritional profile of Spirulina is not complete and will be more effective when combined with a healthy and balanced diet as part of a preventive strategy for self-care. 1 kg of Spirulina has the same nutrients found in about 1,000 kgs of assorted vegetables. Some of the key health benefits of using Spirulina are:
- Boosts the immune system
- Improve digestion
- Reduce fatigue
- Build endurance
- Detoxifier – cleanses the body
- Boosts energy levels
- Controls appetite
- Keeps a tab on cardiovascular function
- Helps proper liver and kidney functioning
- Reduces inflammation and allergies
AIDS/HIV, arthritis, athletic nutrition, enhancing natural cleansing and detoxification, supporting cardiovascular function and healthy cholesterol, strengthening the immune system, improving gastrointestinal and digestive health, reducing cancer risks with antioxidant protection, general and long term health.
During 1970-1980, at the time when spirulina was launched on the market, the market for food supplements was not organised and regulated as is the case today. It was in 1981 that the marketing of spirulina, and especially its mediatization really started. The boom in consumption was due to a front-page article in a US daily newspaper vaunting the properties of spirulina as a hunger reducer for people on a diet. Other media took up the subject and very quickly, demand exploded in the USA. Hundreds of companies entered the market to offer their spirulina, when production in 1981 only amounted to 500 tons/year, the majority of which was already bought by Japan. The result was that the products sold in the USA contained very little spirulina.
At present, companies that produce high-quality spirulina try to keep their market share by stressing the quality aspect, and at the same time, they are developing products with higher added value, extracting from spirulina components that they sell to other industries: food colouring, fluorescent markers, enzymes, etc. Genetically modified spirulina is also being developed, like spirulina with high iron, beta-carotene, zinc, etc. content.
Spirulina is now commercially available in tablet or powder form. Some health tonics contain spirulina as part of their ingredients.
Prominent Players in the Spirulina Market
- Parrys Nutraceuticals, India
- Cyanotech, Hawaii, USA
- Hydrolina Biotech, India
- Nutrex Hawaii, USA
- Australian Spirulina, Australia
Challenges in Spirulina Production
- Individual spirulina filaments are destroyed by prolonged strong illumination ("photolysis"), therefore it is necessary to agitate the culture in order to minimize the time they are exposed to full sunlight.
Research Efforts in Spirulina
While there have been only a handful of spirulina studies conducted on humans, its test tube and animal study results are certainly interesting and might one day merit a look from pharmaceutical companies.
In vitro research
Spirulina has been studied in vitro against HIV, as an iron-chelating agent, and as a radioprotective agent. Animal studies have evaluated spirulina in the prevention of chemotherapy-induced heart damage, stroke recovery, age-related declines in memory, diabetes mellitus, in amyotrophic lateral sclerosis, and in rodent models of hay fever. Mouse studies suggest that spirulina has little effect on the metabolism, and therefore is unlikely to be effective as a weight-loss agent.
In humans, small studies have been undertaken evaluating spirulina in undernourished children, as a treatment for the cosmetic aspects of arsenic poisoning, in hay fever and allergic rhinitis, in arthritis, in hyperlipidemia and jypertension, and as a means of improving exercise tolerance.
At present, these studies are considered preliminary. According to the U.S. National Institutes of Health, at present there is insufficient scientific evidence to recommend spirulina supplementation for any human condition, and more research is needed to clarify its benefits, if any.
Many medical and educational institutions are researching on various aspects of spirulina. A few of them are:
- University of Mississippi: The National Center for Natural Products Research at the University of Mississippi is carrying out considerable amount of research on various applications and benefits of Spirulina. Dr. David Pasco, assistant director of the research center, focuses on developing biological screens that use molecular tools to identify compounds within plants that contribute to their health benefits, especially those that exhibit immune enhancing and anti-cancer properties. His research also deals with the isolation and identification of innate immune enhancing components within natural products that have been used traditionally to enhance immune function. Some of this research has led to the development of two patented and commercialized botanical extracts, one for general enhancement of immune function (Spirulina extract-Immulina®) and the other for improving skin elasticity and wrinkle reduction (fraction from Aloe vera). Numerous clinical trials have been conducted using these products and several more are underway.
Some of their publications can be found at:
- Oregon State University
Oregon State University reports on a 2005 study headed by The University of South Florida’s Paula Bickford, PhD. Dr. Bickford and her colleagues at James A. Haley Veteran’s Hospital and the National Institute on Drug Abuse found that, following induced strokes, rats which had been given diets supplemented with spirulina showed brains lesions 75% smaller than those of control group rats. The rats fed spirulina also recovered mobility to a greater extent.
• The Health Information Center at Cedars-Sinai Hospital in Los Angeles references a second study by Dr. Bickford’s team in which the brains of aged rats fed spirulina supplements maintained their neuron function much better, and showed far less free radical damage than those of rats fed cucumbers. Bickford’s research is significant because it indicates that spirulina may be helpful in warding off the free radical damage related to aging diseases like Parkinson’s and Huntington’s Disease.
• Kansas State University’s International Food Safety Network has published a 2005 article from the Decca, India Herald reporting that Spirulina is approved by both the FDA and the World Health Organization for use as a health food, and mentions it as a source of five essential amino acids which the human body cannot manufacture. The article also refers to spirulina’s high mineral content, in particular the amount of iron it contains, its abilities to reduce gastro enteric distress by promoting the growth of intestinal bacteria, and to help prevent gastro enteric infection; and its cholesterol-reducing effects.
• The abstract of a 2002 study by the Department of Animal Sciences at India’s University of Hyderabad from the US National Institutes of Health’s research data publication site, also cited by the University of Maryland Medical Center, explains the process by which spirulina is able to inhibit the elevated levels of Cycloxygenase-2 associated with inflammation and cancer.
• A second 2002 study at Havana’s Ozone International Center showed that phycocyanin from spirulina acted as an anti-inflammatory in protecting live mice which had been injected with arthritis-inducing Zymosan. The mice showed no cartilage damage and an inhibited inflammatory response after receiving spirulina for eight days following their Zymosan injections. The animal nutritionals maker Pharma Chemie of Syracuse, NY has since gone on to patent a compound containing phycocyanin, which gives spirulina its blue-green color, as an anti-inflammatory for use in animals.
The UMM site also goes on to mention a Kerala, India study of eighty-seven human subjects in which 45% of those exhibiting oral cancer lesions caused from chewing tobacco experienced complete regression of their symptoms after receiving one gram of spirulina fusiformus daily for twelve months.
• The NYU Medical Center Hospital for Joint Diseases has, on its Center for Children website, a review of some of the research and claims made concerning the health benefits of spirulina. The NYU site mentions that spirulina has shown preliminary promise as in fighting HIV; and its potential against HIV and other viruses was demonstrated in a 1998 Dana-Farber Cancer Institute andHarvard Medical School study.
The NYU site also references other numerous but preliminary test tube, animal and human studies which suggest that spirulina might help lower cholesterol and reduce hypertension; prevent cancer; strengthen the liver’s defense against toxins; and alleviate allergic reactions.
• Spirulina’s effectiveness in fighting allergies was shown in 2005 UC Davis research in which thirty-six rhinitis sufferers were treated with spirulina supplementation, and those who took two grams daily experienced a significant reduction in their allergic symptoms. That research followed a 2000UC Davis study which showed that when incubated spirulina dilutions, cultured human mononuclear blood cells, including macrophages and lymphocytes, are able to mount a stronger immune response.
1. Growth and content of Spirulina platensis biomass chlorophyll cultivated at different values of light intensity and temperature using different nitrogen sources.
Eliane Dalva Godoy Danesi; Carlota Oliveira Rangel-Yagui; Sunao Sato; Joăo Carlos Monteiro de Carvalho
Braz. J. Microbiol. vol.42 no.1 Săo Paulo Jan./Mar. 2011
The effects of light intensity and temperature in S. platensis cultivation with potassium nitrate or urea as nitrogen source were investigated, as well as the biomass chlorophyll contents of this cyanobacteria, through the Response Surface Methodology. Experiments were performed at temperatures from 25 to 34.5°C and light intensities from 15 to 69 µmol photons m-2 s-1, in mineral medium. In cultivations with both sources of nitrogen, KNO3 and urea, statistic evaluation through multiple regression, no interactions of such independent variables were detected in the results of the dependent variables maximum cell concentration, chlorophyll biomass contents, cell and chlorophyll productivities, as well as in the nitrogen-cell conversion factor. In cultivation performed with both sources of nitrogen, it was possible to obtain satisfactory adjustments to relate the dependent variables to the independent variables. The best results were achieved at temperature of 30°C, at light intensity of 60 µmol photons m-2 s-1, for cell growth, with cell productivity of approximately 95 mg L-1 d-1 in cultivations with urea. For the chlorophyll biomass content, the most adequate light intensity was 24 µmol photons m-2 s-1.
2.The effects of Spirulina on anemia and immune function in senior citizens
Carlo Selmi, Patrick SC Leung, Laura Fischer, Bruce German, Chen-Yen Yang, Thomas P Kenny, Gerry R Cysewski and M Eric Gershwin
Cellular & Molecular Immunology (2011) 8, 248–254; doi:10.1038/cmi.2010.76; published online 31 January 2011
Anemia and immunological dysfunction (i.e. immunosenescence) are commonly found in older subjects and nutritional approaches are sought to counteract these phenomena. Spirulina is a filamentous and multicellular bule-green alga capable of reducing inflammation and also manifesting antioxidant effects. We hypothesized that Spirulina may ameliorate anemia and immunosenescence in senior citizens with a history of anemia. We enrolled 40 volunteers of both sexes with an age of 50 years or older who had no history of major chronic diseases. Participants took a Spirulina supplementation for 12 weeks and were administered comprehensive dietary questionnaires to determine their nutritional regimen during the study. Complete cell count (CCC) and indoleamine 2,3-dioxygenase (IDO) enzyme activity, as a sign of immune function, were determined at baseline and weeks 6 and 12 of supplementation. Thirty study participants completed the entire study and the data obtained were analyzed. Over the 12-week study period, there was a steady increase in average values of mean corpuscular hemoglobin in subjects of both sexes. In addition, mean corpuscular volume and mean corpuscular hemoglobin concentration also increased in male participants. Older women appeared to benefit more rapidly from Spirulina supplements. Similarly, the majority of subjects manifested increased IDO activity and white blood cell count at 6 and 12 weeks of Spirulina supplementation. Spirulina may ameliorate anemia and immunosenescence in older subjects. We encourage large human studies to determine whether this safe supplement could prove beneficial in randomized clinical trials.
3.Antioxidant effects and UVB protective activity of Spirulina (Arthrospira platensis) products fermented with lactic acid bacteria
Jiang-Gong Liu, Chien-Wei Hou, Shin-Yi Lee, Yaju Chuang, Chih-Cheng Lin
Process Biochemistry, Volume 46, Issue 7, July 2011, Pages 1405-1410
Phycocyanin in Spirulina (currently named Arthrospira platensis) acts as an antioxidant in various biological systems. The antioxidant, anti-inflammatory, antibacterial, and UV protective activity of unadulterated Arthrospira (UAP) and the product of Arthrospira fermented with lactic acid bacteria (FAP) were assayed in skin-care models. The results showed that both UAP and FAP had skin-care activities in all tested models, except for anti-bacterial activity. FAP scavenged DPPH (1,1-diphenyl-2-picrylhydrazyl) radical and nitric oxide, along with anti-inflammatory and UV protective activities, all of which varied with the dose used, but nevertheless, were significantly higher than those found in UAP. The UV protective activity of FAP was also significantly higher (p < 0.05) than that of UAP. The total phenol content increased up to 1.73 fold, which suggested the cell walls of the algae were subjected to biodegradation during fermentation, resulting in the release of smaller molecules with higher antioxidant activities. Moreover, the level of phycocyanobilin in FAP was higher than in UAP. These results suggest that Arthrospira fermented by symbiotic lactic acid bacteria released unidentified polyphenols and converted phycocyanin to phycocyanobilin, providing these activities. Therefore, FAP has a greater potential for use in skin-care products than UAP.
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