Spirulina

Scientific Name(S): Spirulina spp. Family: Oscillatoriaceae

Common Name(S): Spirulina, dihe, tecuitlatl, blue-green algae

Botany

The term spirulina encompasses several thousand species of cyanophyta (blue-green algae), a few of which have been used by humans. These organisms, which take the form of microscopic, corkscrew-shaped filaments, can be found around the world. In some locations they impart a dark-green color to bodies of water. They are noted for their characteristic behavior in carbonated water and their energetic growth in laboratory cultures.

Uses

Spirulina is sold in the US as a health food or health food supplement and has also been reported to enhance antibody production, improve dietary hyperlipidemia, reduce gastric secretory activity, exert a preventative effect on liver triglycerides, and cause tumor regression.

Side Effects

Spirulina is nontoxic in humans.

History

Spirulina has been known at least since the 16th century. Spanish explorers found the Aztecs harvesting a "blue mud" that probably consisted of spirulina. The mud, which was dried to form chips or formed into cheese-like loaves, was obtained from Lake Texcoco, in what is now Mexico. Spirulina was similarily harvested by natives of the Sahara Desert, where it was known by the name dihe. Spirulina has been sold in the United States as a health food or food supplement since about 1979. It is available as a fine powder or tablets. Some authors have suggested the use of spirulina as a source of protein.

Chemistry

Spirulina consists of approximately 65% crude protein and high levels of B-complex vitamins. The protein content includes all 22 amino acids, but the balance of these is not as desirable as that in many types of animal protein. Spirulina preparations contain iron at levels of 300 to 400 ppm dry weight. Unlike many forms of plant iron, this iron has a high bioavailability when ingested by humans. A dosage of 10 g/day can contain 1.5 to 2 mg absorbable iron. Trace elements present at high levels include manganese, selenium, and zinc. Also concentrated in the organisms are calcium, potassium, and magnesium. Spirulina is the first prokaryote found to contain a ferredoxin. Ferredoxin obtained from S. maxima is a stable, easily extractable plant type. A superoxide dismutase has been isolated from S. platensis.

Summary

Spirulina is a blue-green algae that is used as a food and food supplement. It contains high levels of protein and B-complex vitamins; the nutritional value, particularly of the latter, has been questioned. Spirulina represents an expensive source of dietary protein and iron. Reports find spirulina effective in tumor regression, chemo- and radioprotection, virus inhibition, and enhancing antibody production. Spirulina seems to be nontoxic in humans but may harbor some contaminants such as heavy metals or microbes.