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Spirulina

Other name(s):

Spirulina fusiformis, Spirulina maxima, Spirulina platensis

General description

Spirulina is a primitive single-celled algae that grows in the ocean and includes many species. Commonly used species include Spirulina maxima and Spirulina platensis. Spirulina is cultivated as feedstock in Africa and Mexico.

Known ingredients of spirulina include:

  • Arachidonic acid

  • Gamma-linolenic acid (GLA)

  • Iron

  • Linoleic acid

  • Phycocyanin

  • Protein

  • Vitamin B12

Medically valid uses

There are no clearly demonstrated medical uses for spirulina in humans. Spirulina is a source of protein, iron, carotenoids, and some vitamins. The protein in spirulina is comparable to other plant proteins and, like other plant proteins, is incomplete, meaning it does not contain all nine essential amino acids.

Spirulina has been used as a feed extender for livestock. It can provide a percentage of the total protein intake (usually up to 25 percent) but must be supplemented with amino acids that are lacking in spirulina protein (generally lysine, methionine, and histidine). Digestibility of spirulina protein is less than that of other typical livestock foods.

Spirulina can also be used as a source of protein and some vitamins for humans if a tested source is consumed. Spirulina can be contaminated with microbes, heavy metals (including mercury, cadmium, lead, or arsenic), and radioactive divalent and trivalent metal ions. As Spirulina is an incomplete protein, it should not be used as a main source of protein.   

Unsubstantiated claims

Please note that this section reports on claims that have NOT yet been substantiated through scientific studies.

Most studies of spirulina have been conducted on animals, principally mice, but not on humans. The claims made are thus only supported by animal studies. These claims state that spirulina may act as a hepatoprotectant (protect the liver from damage from certain toxins), may reduce allergic reactions by stabilizing mast cells (activated mast cells are a source of histamine, the agent that causes allergic symptoms), and may strengthen the immune system.

One study using human subjects suggests spirulina may help treat oral cancerous lesions.

Dosing format

Follow packaging instructions for correct dose. Women who are pregnant or breast-feeding should consult a physician before taking any dietary supplements.

Side effects, toxicity, and interactions

Spirulina is a controversial source of vitamin A, because spirulina has been shown to interfere with the body's storage and use of both vitamin A and E. Spirulina is not a reliable source of vitamin B12.

People taking warfarin (Coumadin) should talk to their doctor before taking spirulina supplements since they could interfere with the effectiveness of this blood thinner. 

Additional information

Click here for a list of reputable websites with general information on nutrition.

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