Spirulina - blue green algae

Spirulina is used by holistic therapist for cancer prevention, here is a trusted report of its effectiveness.

http://www.mskcc.org/cancer-care/herb/blue-green-algae

Clinical Summary
Blue-green algae, also known as Cyanobacteria, are primitive autotrophic prokaryotes. They are a source of food in some parts of the world and patients take the supplemental form to prevent and treat cancer and viral infections, and for weight loss. Spirulina species are cultured in alkaline fresh water whereasAphanizomenon flos aquae (AFA) is naturally grown and harvested from Upper Klamath Lake, Oregon, USA. Blue-green algae products frequently contain one or both of these strains of algae.
Studies have shown that spirulina may be effective against allergic rhinitis ⁽⁵⁾, in managing diabetes ⁽³⁾, and showed a cholesterol-lowering effect in patients with nephrotic syndrome-induced hyperlipidemia ⁽⁴⁾. Preliminary data indicate that it may also be a safe and effective agent in the treatment of chronic hepatitis C virus infection ⁽¹⁹⁾.

Animal studies suggest that spirulina has chemoprotective and radioprotective effects ⁽⁶⁾, but human data are lacking.
Blue-green algae may be contaminated by strains of algae (e.g. microcystin species) that are toxic.

Constituents

• Proteins (50-70%): All essential amino acids
• Carbohydrates: Rhamnose, ribose, mannose, fructose, polysaccharides
• Vitamins: A, E, cyanocobalamin, niacin, choline, folic acid, thiamine
• Other: Chlorophyll, copper, magnesium, zinc, potassium

Warnings

Microcystin contamination can cause hepatotoxicity, renal failure, and neurotoxicity. Products should be certified free from contamination.