Spirulina is a diverse group of blue-green algae that grows naturally in salt-water lakes in Africa and Mexico, as well as in some fresh water lakes. As the name indicates, the algae grow in a spiral shape. It is a popular dietary supplement.
Spirulina is also known as blue-green algae, Spirulina fusiformis, S. maxima, S. platensis and Arthrospira plantensis. It grows quickly, is easy to harvest and history records indicate that the Spanish conquistadors observed the Aztecs using it as a food source. Spirulina is purportedly rich in vitamins, minerals and carotenoids, making it a popular nutritional supplement. Spirulina is sold in health food shops and online in tablet form and as a powder or in flakes.
What benefits are associated with taking spirulina?
Spirulina is primarily taken as a nutritional supplement. The algae itself is nutritious, and as well as having vitamins and minerals, spirulina is a non-animal source of vitamin B12. However, vitamin B12 in this form cannot be absorbed by people. The algae is rich in protein but you would have to consume a considerable amount of tablets for your body to get enough protein. Other forms of protein, found in animal sources, pulses, nuts and grains, are better, less costly, alternatives.
Spirulina has been touted as being able to help prevent cancer, fight off infections, help counter allergies such as hay fever, provide liver protection, help improve cholesterol levels and help with weight loss, amongst many other claims. Limited studies have been done on animals and in test tubes that suggest spirulina could increase the production of infection-fighting cells that may improve immunity and fight off certain chronic illnesses. However, no, or only preliminary studies, have been carried out on humans that can substantiate these claims.
For example, a pilot study in Egypt, published in 2012, involving only 30 patients with chronic hepatitis C taking spirulina, concluded that the algae could have a potential therapeutic use in treating people with the condition, but more research is needed to back these claims.
A 2012 review looking at the data of 14 trials on spirulina being used as a supplementary food or daily supplement for HIV-positive adults and children found that there was no evidence that supplements led to a reduction in the disease's progress or HIV-related complications.
How effective is spirulina?
The Natural Medicines Comprehensive Database looks at the scientific evidence available and gives a rating based on the natural medicine's or supplement's effectiveness. It lists 'blue-green algae' as having insufficient evidence to rate effectiveness for helping with the following: