Spirulina (dietary Supplement) - Algae For Weight Loss

Spirulina is a cyanobacterium that can be consumed by humans and other animals. There are two species, Arthrospira platensis and Arthrospira maxima.

Arthrospira is cultivated worldwide; used as a dietary supplement as well as a whole food; and is also available in tablet, flake and powder form. It is also used as a feed supplement in the aquaculture, aquarium and poultry industries.

Nutrient and vitamin content

Protein

Dried spirulina contains about 60% (51-71%) protein. It is a complete protein containing all essential amino acids, though with reduced amounts of methionine, cysteine and lysine when compared to the proteins of meat, eggs and milk. It is, however, superior to typical plant protein, such as that from legumes.

The U.S. National Library of Medicine said that spirulina was no better than milk or meat as a protein source, and was approximately 30 times more expensive per gram.

Other nutrients

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 (thiamine), B₂ (riboflavin), B₃ (nicotinamide), B₆ (pyridoxine), B₉ (folic acid), vitamin C, 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, 7-hydroxyretinoic acid, isomers, chlorophyll-a, xanthophyll, echinenone, myxoxanthophyll, canthaxanthin, diatoxanthin, 3'-hydroxyechinenone, beta-cryptoxanthin, and oscillaxanthin, plus the phycobiliproteins c-phycocyanin and allophycocyanin.

Vitamin B₁₂ controversy

Spirulina is not considered to be a reliable source of Vitamin B₁₂. Spirulina supplements contain predominantly pseudovitamin B₁₂, which is biologically inactive in humans. Companies which grow and market spirulina have claimed it to be a significant source of B₁₂ on the basis of alternative, unpublished assays, although their claims are not accepted by independent scientific organizations. The American Dietetic Association and Dietitians of Canada in their position paper on vegetarian diets state that spirulina cannot be counted on as a reliable source of active vitamin B₁₂. The medical literature similarly advises that spirulina is unsuitable as a source of B₁₂.

Risks

Toxicological studies

Toxicological studies of the effects of spirulina consumption on humans and animals, including feeding as much as 800 mg/kg, and replacing up to 60% of protein intake with spirulina, have shown no toxic effects. Fertility, teratogenicity, peri- and post-natal, and multi-generational studies on animals also have found no adverse effects from spirulina consumption.

Quality-related safety issues

Spirulina is a form of cyanobacterium, some of which are known to produce toxins such as microcystins, BMAA, and others. Some spirulina supplements have been found to be contaminated with microcystins, albeit at levels below the limit set by the Oregon Health Department. Microcystins can cause gastrointestinal disturbances and, in the long term, liver cancer. The effects of chronic exposure to even very low levels of microcystins are of concern, because of the potential risk of cancer.

These toxic compounds are not produced by spirulina itself, but may occur as a result of contamination of spirulina batches with other toxin-producing blue-green algae. Because spirulina is considered a dietary supplement in the U.S., there is no active, industry-wide regulation of its production and no enforced safety standards for its production or purity. The U.S. National Institutes of Health describes spirulina supplements as "possibly safe", provided they are free of microcystin contamination, but "likely unsafe" (especially for children) if contaminated. Given the lack of regulatory standards in the U.S., some public-health researchers have raised the concern that consumers cannot be certain that spirulina and other blue-green algae supplements are free of contamination.

Heavy-metal contamination of spirulina supplements has also raised concern. The Chinese State Food and Drug Administration reported that lead, mercury, and arsenic contamination was widespread in spirulina supplements marketed in China.

Safety issues for certain target groups

Due to very high Vitamin K content, patients undergoing anticoagulant treatments should not change consumption patterns of spirulina without seeking medical advice to adjust the level of medication accordingly.

Like all protein-rich foods, spirulina contains the essential amino acid phenylalanine (2.6-4.1 g/100 g), which should be avoided by people who have phenylketonuria, a rare genetic disorder that prevents the body from metabolizing phenylalanine, which then builds up in the brain, causing damage.

Etymology and ecology

The maxima and plaetensis species were once classified in the genus Spirulina. There is now agreement that they are in fact Arthrospira; nevertheless, and somewhat confusingly, the older term Spirulina remains in use for historical reasons.

Arthrospira are free-floating filamentous cyanobacteria characterized by cylindrical, multicellular trichomes in an open left-hand helix. They occur naturally in tropical and subtropical lakes with high pH and high concentrations of carbonate and bicarbonate. Arthrospira platensis occurs in Africa, Asia and South America, whereas Arthrospira maxima is confined to Central America. 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, Bangladesh, Pakistan, Burma (a.k.a. Myanmar), Greece, and Chile.

Spirulina thrives at a pH around 8.5 +, which will get more alkaline, and a temperature around 30 °C (86 °F). They are able to make their own food, and do not need a living energy or organic carbon source. In addition, spirulina have to have an ensemble of nutrients to thrive in a home aquarium or pond. A simple nutrient feed for growing Spirulina is:

• Baking soda- 16 g/L (61 g/US gal)
• Potassium nitrate- 2 g/L (7.6 g/US gal)
• Sea salt- 1 g/L (3.8 g/US gal)
• Potassium phosphate- 0.1 g/L (0.38 g/US gal)
• Iron sulphate- 0.0378 g/L (0.143 g/US gal)

which can all be found in aquarium or else in the agricultural division, all commonly occurring compounds except for the iron sulphate. The algae has actually been tested and successfully grown in human urine at 1:180 parts. After 7days, 97% of NH4+-N, 96.5% of total phosphorus (TP) and 85-98% of urea in the urine (ca. 120-diluted) were removed by the microalgae under autotrophic culture (30 °C).

Historical use

Spirulina was a food source for the Aztecs and other Mesoamericans until the 16th century; the harvest from Lake Texcoco and subsequent sale as cakes were described by one of Cortés' soldiers. The Aztecs called it "tecuitlatl".

Spirulina was found in abundance at Lake Texcoco by French researchers in the 1960s, but there is no reference to its use by the Aztecs as a daily food source after the 16th century, probably due to the draining of the surrounding lakes for agricultural and urban development. The first large-scale spirulina production plant, run by Sosa Texcoco, was established there in the early 1970s.

Spirulina has also been traditionally harvested in Chad. It is 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.

Research

At present, research is preliminary. According to the U.S. National Institutes of Health, there is insufficient scientific evidence to recommend spirulina supplementation for any human condition, and more research is needed to clarify its benefits, if any.

Administration of spirulina has been investigated as a way to control glucose in people with diabetes, but the EFSA rejected those claims in 2013.

Advocates

In 1974, the World Health Organization described Spirulina as "an interesting food for multiple reasons, rich in iron and protein, and is able to be administered to children without any risk," considering it "a very suitable food." The United Nations established the Intergovernmental Institution for the use of Micro-algae Spirulina Against Malnutrition in 2003.

In the late 1980s and early 90s, both NASA (CELSS) and the European Space Agency (MELISSA) proposed Spirulina as one of the primary foods to be cultivated during long-term space missions.

See also

• Algaculture - commercial farming of algae
• Aphanizomenon flos-aquae

Notes and references

External links

• "Blue-green Algae". MedlinePlus. National Institutes of Health. December 2011. 
• "Blue-green Algae". Memorial Sloan-Kettering Cancer Center. December 2011. 
• "Spirulina". University of Maryland Medical Center. June 2011. 
• "Spirulina". Beth Israel Deaconess Medical Center. August 2011. 
• "Intergovernmental Institution for the use of Micro-algae Spirulina Against Malnutrition". 

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