Author: Winston Craig, MPH, PhD, RD.

Is Blue-Green Algae a Superfood?


 Spirulina tablets

Blue-green algae are microscopic plants which are more closely akin to bacteria than to seaweed. The popular blue-green algae, spirulina, is currently cultivated and harvested on an industrial scale in several countries and commonly sold as a weight-loss agent, or as a general nutritional supplement.

Spirulina refers to a large number of blue-green algae that are harvested from the ocean or lakes (such as Klamath Lakes in Oregon) and include Spirulina maxima and S. platensis. Spirulina does contain a variety of nutrients, such as protein, a variety of B vitamins and minerals, the antioxidants beta-carotene and vitamin E, and phycocyanin.

Spirulina Is No Panacea

People have claimed that spirulina can be used to successfully treat various medical conditions, such as asthma, depression, digestive problems, fatigue, HIV infection, hypertension, skin disorders, stress, and attention deficit disorder. In addition, it is supposed to improve the memory, boost immunity, protect the liver, boost energy levels, and detoxify the body. However, there is no scientific evidence to support any of these claims. Recently, marketers of blue-green algae were asked to stop making false health claims about their product.

Although spirulina is commonly marketed as an appetite suppressant, there is no evidence that it is successful in weight reduction plans. At present, there is no strong evidence that spirulina can actually treat or cure any illness.

Blue is Beautiful

Phycocyanin, the blue pigment in spirulina, can act as a free radical scavenger and powerful antioxidant. Rat studies have demonstrated that phycocyanin can exert a wide range of anti-inflammatory effects. Experiments in mice show that phycocyanin can accelerate wound healing and may help in the healing of ulcers. A heaping tablespoon of spirulina provides about 100 mg of phycocyanin.

The non-toxic pigment, phycocyanin, is used in the food and beverage industry as a natural blue coloring agent. It is used in sweets, soft drinks, chewing gum, ice cream, and other desserts as well as cosmetics. Spirulina is also added to health drinks.

There is data showing that spirulina possesses some anti-viral and anti-tumor properties. Preliminary animal data also suggests it may be useful as a lipid-lowering agent.


Typically, blue-green algae is sold in tablet, capsule, or powder form. It is safe to use when consumed in recommended doses of 1 to 2 grams taken three times a day. Side effects are few, but allergies are known. Skin reactions, nausea and upset stomach have also been reported. Because of its high nucleic acid content, excessive consumption of spirulina may increase blood uric acid levels to undesirable levels. Due to the high iodine content of spirulina, patients with thyroid conditions should not use spirulina as it may decrease the action of thyroid hormone.


  1. KORE August 18, 2016
    • admin September 17, 2016
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