What Is Chlorella Vulgaris?

Chlorella vulgaris is a green algae found in most bodies of fresh water. Included in many dietary supplements as an immune system booster, Chlorella vulgaris consists mostly of lutein and may also have industrial uses for producing energy and making processed foods more visually appealing. Scientific studies support each of these uses for Chlorella vulgaris, but clinical evidence for the health benefits to humans of ingesting Chlorella vulgaris does not exist.

Dietary Supplement

• Chlorella vulgaris has antioxidant and probiotic properties, meaning it prevents cell damage and increases the numbers of beneficial bacteria along the digestive tract and in the intestines when ingested. As summarized in a PDRhealth fact sheet, having large colonies of "good" bacteria can help people avoid and relieve cancer radiation treatment side effects, colitis, constipation, Crohn's disease, diverticulitis and ulcers. Proponents of Chlorella vulgaris also claim that it fights cancer and lowers blood pressure.

Evidence for Effectiveness

• Animal and laboratories studies have shown that Chlorella vulgaris limits the damage of some bacterial infections and can shrink cancerous tumors. However, these effects of Chlorella vulgaris supplementation have yet to be conclusively demonstrated in humans. In one laboratory experiment reported in the journal "Toxicology In Vitro" in March 2007, Italian researchers demonstrated that a combination of Chlorella vulgaris and daidzein protected pig intestine tissue from damage by Escherichia coli.

  As early as 1985, F. Konishi and colleagues reported in the journal "Cancer Immunotherapy, Immunology" that infecting a tea-like solution of Chlorella vulgaris into mice with advanced cancer significantly prolonged the mice's lives. Working in a lab decades later, C. H. Cha, S. Y. Koo and D. U. Lee showed that extracts of two species of Chlorella inhibited the growth of human cancer cells in a petri dish. Writing in the November 26, 2008, "Journal of Food and Agricultural Chemistry," Cha and colleagues noted that "semipurified extracts of C. ellipsoidea and C. vulgaris inhibited HCT116 cell growth in a dose-dependent manner."

Supplement Side Effects

• Some patients taking Chlorella vulgaris have experienced an allergic reaction marked by chest pain or tightness, trouble breathing and hives. Chlorella vulgaris can also cause nausea and make people more sensitive to sunlight.

Supplement Products

• The Dietary Supplement Labels Database maintained by the National Institutes of Health's National Library of Medicine lists 48 brand-name products that contain Chlorella vulgaris. Each of the listed products includes Chlorella vulgaris as one of dozens of vitamins, minerals, and plant and fruit extracts. Federal health experts have not established a recommended daily value for Chlorella vulgaris, so supplements can deliver anywhere between 2.5 mg of the algae, as does Radiance's Maximum Anti-Oxidant Formula, to 50 mg, as does GNC's Ultra Mega Green.

Industrial Uses

• Chlorella vulgaris shows promises as a biomass fuel and as a natural food coloring agent. Because the algae grows rapidly in light and dark places with a minimum of nutrients, large amounts of flammable-when-dried Chlorella vulgaris can be produced at low cost. Another property of Chlorella vulgaris---its ability to mimic the action of fatty acids---allows it to be used as a medium for adding natural colorants such as pea oil to other foods.