Spirulina is a type of blue-green algae of which there are several species. It grows best in a warm climate and in warm alkaline water. Spirulina was historically used by the Mexican (Aztec, Mayan), African, and Asian peoples, who consumed it as a staple for thousands of years.

Spirulina is a rich source of nutrients, especially protein. It is rich in phycocyanin, a blue polypeptide that gives spirulina its blue-green color. Phycocyanin has the ability to stimulate the production and activity of both white and red blood cells and to increase the production of antibodies and cytokines, which help fight foreign invasions. Because of these properties, spirulina has been used extensively in Russia to treat the victims, especially children, of the nuclear disaster at Chernobyl. In these children whose bone marrow had been damaged from radiation exposure, spirulina promoted the evacuation of radionucleotides and stimulated T-cell production, which boosted the immune system of these patients.

Spirulina is a microalgae that flourishes in warm climates and warm alkaline water. It is available dried and freeze-dried.

Spirulina is a complete protein—62% of it is made up of essential and nonessential amino acids. It is also thought to provide the entire B complex of vitamins, though its vitamin B₁₂ content has been called into question. It is also rich in phycocyanin, chlorophyll, beta-carotene and other carotenoids, vitamin E, minerals (e.g., zinc, manganese, copper, iron), trace minerals (e.g., selenium), and essential fatty acids (e.g., gamma-linolenic acid). Because the cell walls of spirulina are made of complex proteins and sugars (unlike other species of blue-green algae whose walls are made up of cellulose), it is very easily digested. The exact nutrient profile depends on the species.

Most spirulina consumed in the United States is cultivated scientifically. There are many different spirulina species, only some of which are identified on commercial preparations. Spirulina maxima (cultivated in Mexico) and Spirulina platensis (cultivated in California) are the most popular.

Currently, spirulina has the following uses:

• Anemia. Spirulina promotes hematopoiesis (formation and development of blood cells).
• Skin disorders. Because spirulina is rich in gamma-linolenic acid, it helps to maintain healthy skin and treat several skin disorders (such as eczema and psoriasis).
• Vitamin A deficiency. Studies in India determined that Spirulina fusiformis is an effective source of dietary vitamin A.
• Colitis. One study showed that a component of spirulina, C-phycocyanin, reduced inflammation caused by acetic acid-induced colitis in rats. It also showed some reduction in colonic damage.

Clinical applications of spirulina include malabsorption syndrome with gas and bloating, general immune support, and as an easily absorbed protein supplement for people with a lack of appetite. It is also used in the treatment of Candida and hypogylcemia. It is often used by weight lifters as a protein source.

Patients should consult their health care providers for the correct dosage of spirulina. However, a standard dose of spirulina is four to six 500 mg tablets per day.

No adverse effects were found after high-dose experiments in animals.

No fetotoxicity nor teratogenicity was found when high doses of spirulina were administered to pregnant animals.

No clinically significant interactions between spirulina and conventional medications are known to have been reported in the literature to date.

Annapurna VV, Deosthale YG, Bamji MS. Spirulina as a source of vitamin A. Plant Foods Hum Nutr. 1991;41:125-134.

Chamorro G, Salazar M, Favila L, Bourges H. Pharmacology and toxicology of Spirulina algae. Rev Invest Clin. 1996;48:389-399. abstract.

Chamorro G, Salazar M. Teratogenic study of spirulina in mice. Arch Latinoam Nutr. 1990;40:86-94.

Gonzalez R, Rodriguez S, Romay C, et al. Anti-inflammatory activity of phycocyanin extract in acetic acid-induced colitis in rats. Pharmacol Res. 1999;39:1055-1059.

Hayashi K, Hayashi T, Kojima I. A natural sulfated polysaccharide, calcium spirulan, isolated from Spirulina platensis: in vitro and ex vivo evaluation of anti-herpes simplex virus and anti-human immunodeficiency virus activities. AIDS Res Hum Retroviruses. 1996;12:1463-1471.

Mathew B, Sankaranarayanan R, Nair PP, et al. Evaluation of chemoprevention of oral cancer with Spirulina fusiformis. Nutr Cancer. 1995;24:197-202.

Qureshi MA, Garlich JD, Kidd MT. Dietary Spirulina platensis enhances humoral and cell-mediated immune functions in chickens. Immunopharmacol Immunotoxicol. 1996;18:465-476.

Romay C, Armesto J, Remirez D, Gonzalez R, Ledon N, Garcia I. Antioxidant and anti-inflammatory properties of C-phycocyanin from blue-green algae. Inflamm Res. 1998;47:36-41.

Salazar M, Martinez E, Madrigal E, Ruiz LE, Chamorro GA. Subchronic toxicity study in mice fed Spirulina maxima. J Ethnopharmacol. 1998;62:235-241.

Shealy NC. The Illustrated Encyclopedia of Healing Remedies. Boston, Mass: Element Books; 1998:277.

Spirulina: good source of beta-carotene, but no miracle food. Environ Nutr. 1995;18:7.

Walker LP, Brown EH. The Alternative Pharmacy. Paramus, NJ: Prentice Hall Press; 1998:51-53.