Blue-Green Algae

Blue-Green Algae: What is it and how does it work in the body?

• Blue-green algae (cyanobacteria) are Gram-negative oxygenic photosynthetic autotrophs that have been used as food in both ancient and present-day civilizations in various continents including Asia, Africa, and South America.

What is it used for and at what dosage?

• Blue-green algae (most commonly Chlorella, Scenedesmus, Spirulina, and Dunaliella) are mainly marketed as having high nutritive value. Spirulina is marketed for is protein, γ-linolenic acid (GLA), and phycocyanin content.

• Researchers and manufacturers also report numerous claims of being a “super food for super health” with claims of having antiviral, anticancer, antidiabetic, antibiotic, immune boosting, hypocholesterolemic and weight loss effects.

• They are also a rich source of vitamins. S. platensis has a higher content of Vitamin B12 and Spirulina is rich in provitamin A, Vitamin E, thiamine, cobalamine, biotin, and inositol.

• The FDA regulates algal products. The status GRAS (generally regarded as safe) was given to Spirulina and Schizochytrium. The microcystin content (discussed below) should not exceed 1 mcg of dry weight for consumption.

• Spirulina has typically been studied in daily dosage of 1–10 g for 2–12 months; however, there is insufficient clinical data to officially guide dosing

Evidence for or against its different uses:

• While cyanobacteria and microalgae are marketed as food supplements with numerous effects on human health, these claims are all largely based on in vitro experiments or on experiments involving animal.

Safety concerns, side effects, and precautions:

• The vast majority of cyanotoxin poisoning (cyanobacterial blooms from blue algae) occur in dogs and livestock.

• A comprehensive literature review dating from 1920s to 2020s demonstrated that half of the incidences were from a contaminated drinking water supply and the other half were from recreational exposure.

• Nowadays, blue-green algae are produced in controlled cultivation processes, harvested within their natural habitats, or in specialized bioreactors.

• Cyanobacteria also produce several potent hepatotoxins and neurotoxins.

• The most well-known is microcystin, which is readily taken up by hepatocytes and cause structural damage. Microcystin is also linked to liver cancer in humans.

• The main routes which human health can be affected include ingestion, inhalation, and skin contact. While microcystin is the most encountered and well studied, there is a large array of other toxins that may be present in these supplements.

• These include BMAA (a neurotoxic amino acid) which has been suggested to be associated with amyotrophic lateral sclerosis/parkinsonism dementia complex or ALS/PDC.

• There is also a large quantity of nucleic acids within algae, which metabolize to uric acid. This can increase the risk of gout or kidney stones, among other adverse health effects.

• However, the current recommended dose of various blue algae (15 of Scenedesmus daily, up to 50 g of Chorella should not pose a concern to increased uric acid—but cautions away from consuming large quantities.

Interactions with medications:

• There have been no well-documented interactions. There has been antiplatelet effects documented in vitro but not in vivo.

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