Blue-green Algae

Health Care Professional Information

Scientific Name
Spirulina sp., Aphanizomenon flos-aquae
Common Name

Spirulina platensis, Spirulina fusiformis, AFA-algae, Arthrospira platensis, tecuitlatl, BGA

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 whereas Aphanizomenon 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.

Purported Uses
  • Appetite suppression
  • Attention deficit hyperactivity disorder
  • Cancer prevention
  • Cancer treatment
  • Fatigue
  • High cholesterol
  • HIV and AIDS
  • Immunostimulation
  • Oral leukoplakia
  • Viral infections
  • Weight loss
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
    (1) (2)
Mechanism of Action

Calcium spirulan, a polysaccharide extract from Spirulina platensis, demonstrates inhibition of HIV-1 viral replication via possible binding and disruption of CD4-gp120 interaction in vitro, although the clinical significance of this is unknown. In vitro, calcium spirulan also inhibits replication of herpes simplex I, cytomegalovirus, and influenza.
In vitro studies also suggest that AFA-algae has antiviral and antimutagenic activity. Other studies showed that spirulina has chemoprotective and radioprotective effects in animals, affected by stimulation of the hemopoietic system. Studies performed in healthy humans suggest that AFA-algae increase the level of circulating natural killer cells.
Although uncommon, several toxins from Microcystis species of algae may contaminate AFA-algae and Spirulina algal blooms. Anatoxin can cause paralysis of respiratory muscles due to irreversible binding and sustained action of the nicotinic acetylcholine receptor. Saxitoxin contamination is thought to block nerve cell neuronal transmission due to binding to voltage-gated sodium channels. Microcystins are cyclic heptapeptides that induce hepatotoxicity.

Spirulina can significantly inhibit cytochrome P450 1A2 and 2E1 enzymes. The same study showed that it also led to significant increase in mRNA/protein levels of CYP2B1 and CYP3A1, but there was no change in the enzyme activities.

(1) (2) (3) (4) (5) (6) (7) (8) (20)

Warnings

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

Adverse Reactions

Anaphylaxis (16)
Case Report: A 28-year-old man developed acute rhabdomyolysis after ingesting Spirulina supplements for one month. His symptoms resolved after discontinuing supplement use (17).
Case Report: A day-old baby was hospitalized for generalized seizures associated with hypercalcemia, found to be related to the mother's long-term consumption of Spirulina supplements (18).
Cyanotoxin (e.g. anatoxin, saxitoxin, microcystins) contamination of AFA-algae and possibly Spirulina may cause hepatotoxicity, renal failure, neurotoxicity, seizures, respiratory arrest, acute pancreatitis, and cardiomyopathy.
(2) (6) (9)

Herb-Drug Interactions
  • Cytochrome P450 substrates: Spriluna inhibits CYP 1A2 and 2E1, and may cause accumulation of drugs metabolized by these enzymes, thereby increasing the risk of their side effects (20).
Literature Summary and Critique

Selmi C, et al. The effects of Spirulina on anemia and immune function in senior citizens. Cell Mol Immunol. 2011 Jan 31.
This study enrolled 40 volunteers, aged 50 years or older, who had been diagnosed with anemia within the previous 12 months. Participants took a Spirulina supplement and completed a nutritional questionnaire for 12 weeks. Complete cell count (CCC) and indoleamine 2,3-dioxygenase (IDO) enzyme activity were measured at baseline and weeks 6 and 12. Over the 12-week study period, there was a steady increase in average values of mean corpuscular hemoglobin (MCH) in the subjects of both genders who completed the study (n=30). The increases in MCH, mean corpuscular hemoglobin volume, and mean corpuscular hemoglobin concentration were found to be statistically significant (p<0.05) for male participants. Over 50% of subjects also achieved increased IDO activity and WBC count at 6 and 12 weeks of Spirulina supplementation. No significant changes in dietary intake were found to have occurred during the study period. The investigators concluded that spirulina may improve anemia and immunosenescence in older subjects. However larger, randomized clinical trials are necessary to confirm these benefits.

Kalafati M, et a;. Ergogenic and antioxidant effects of spirulina supplementation in humans. Med Sci Sports Exerc. 2010 Jan;42(1):142-51.
This double-blind, placebo-controlled, counterbalanced crossover study enrolled moderately conditioned male subjects (n=9) to investigate the effect of spirulina on exercise performance, substrate metabolism, and blood redox status at rest and after exercise. After taking a spirulina supplement daily for 4 weeks, each subject ran on a treadmill at an intensity corresponding to 70-75% of their V02 max for 2 hours, and then at 95% VO2 max until exhaustion. Blood samples were drawn at baseline, immediately after, and at 1, 24, and 48 hours post-exercise. Time to fatigue following the 2 hour run was found to be significantly longer after spirulina supplementation compared to placebo (2.05 + 0.68 vs 2.70 + 0.79 min; p=0.048). During the 2 hour run, spirulina supplementation also decreased carbohydrate oxidation rate by 10.3% (p=0.008) and increased fat oxidation rate by 10.9% (p=0.003), as compared to placebo (p<0.05). Reduced glutathione levels were also significantly higher after spirulina supplementation than after placebo, at rest and 24 hours after exercise (p=0.049). Spirulina supplementation significantly increased exercise performance, fat oxidation, and GSH concentration and reduced exercise-induced lipid peroxidation.

Lee EH. et al. A randomized study to establish the effects of spirulina in type 2 diabetes mellitus patients. Nutr Res Pract. 2008 Winter;2(4):295-300.
This randomized, placebo-controlled study enrolled 37 Korean patients with Type 2 diabetes. Patients received spirulina or placebo for 12 weeks. Spirulina supplementation for 12 weeks was found to significantly lower plasma triglyceride (TG) (p<0.05) and malondialdehyde levels (p<0.05), and also showed a tendency to increase plasma adiponectin levels (p<0.1). The lipid lowering effect of spirulina supplementation differed according to the subject serum levels prior to intervention. Subjects with higher initial TG levels had a greater reduction in plasma TG levels and blood pressure. Subjects with higher initial total cholesterol and LDL-cholesterol levels had a greater reduction in these values, as well as in IL-6 and blood pressure. These results provide evidence that spirulina has a beneficial effect on blood lipid profiles, inflammatory variables, and antioxidant capacity in patients with type 2 diabetes.

Cingi C, et al. The effects of spirulina on allergic rhinitis. Eur Arch Otorhinolaryngol. 2008 Oct;265(10):1219-23.
This randomized, double-blind, placebo controlled-study, evaluated the effectiveness and tolerability of spirulina in the treatment of patients with a history of allergic rhinitis (n=150). Of the patients who completed the study (n=129), patients received either spirulina tablets (n=85) or placebo (n=44). Symptoms (nasal discharge, sneezing, nasal congestion, and itching) were assessed and scored on a four point scale at baseline and at study end. Patients also used a four point scale to grade the severity of their own symptoms. Satisfaction and symptom relief were also graded on a ten point scale by the patients. Spirulina supplementation was found to significantly improve allergic rhinitis symptoms compared to placebo (p<0.001). Patient diaries also revealed a statistically significant difference in effectiveness (p<0.001) and satisfaction (p<0.001) for spirulina compared to placebo. The investigators concluded that spirulina is clinically effective for the treatment of allergic rhinitis, but further studies should be performed to confirm such effects.

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References
  1. Selmi C, Leung PS, Fischer L, et al. The effects of Spirulina on anemia and immune function in senior citizens. Cell Mol Immunol. 2011 Jan 31.
  2. Kalafati M, Jamurtas AZ, Nikolaidis MG, et al. Ergogenic and antioxidant effects of spirulina supplementation in humans. Med Sci Sports Exerc. 2010 Jan;42(1):142-51.
  3. Lee EH, Park JE, Choi YJ, Huh KB, Kim WY. A randomized study to establish the effects of spirulina in type 2 diabetes mellitus patients. Nutr Res Pract. 2008 Winter;2(4):295-300.
  4. Samuels R, Mani UV, Iyer UM, Nayak US. Hypocholesterolemic effect of spirulina in patients with hyperlipidemic nephrotic syndrome. J Med.Food 2002;5:91-6.
  5. Cingi C, Conk-Dalay M, Cakli H, Bal C. The effects of spirulina on allergic rhinitis. Eur Arch Otorhinolaryngol. 2008 Oct;265(10):1219-23.
  6. Zhang H, et al. Chemo- and radio-protective effects of polysaccharide of Spirulina platensis on hemopoietic system of mice and dogs. Acta Pharmacol Sin. 2001;22:1121-4.
  7. Premkumar K. et al. Effect of Spirulina fusiformis on cyclophosphamide and mitomycin-C induced genotoxicity and oxidative stress in mice. Fitoterapia 2001;72:906-11.
  8. Mathew B, et al. Evaluation of chemoprevention of oral cancer with Spirulina fusiformis. Nutr Cancer 1995;24:197-202.
  9. Draisci R, et al. Identification of anatoxins in blue-green algae food supplements using liquid chromatography-tandem mass spectrometry. Food Addit Contam 2001;18:525-31.
  10. Patocka J. The toxins of Cyanobacteria. Acta Medica 2001;44:69-75.
  11. Iwasa M, Yamamoto M, Tanaka Y, Kaito M, Adachi Y. Spirulina-associated hepatotoxicity. Am.J Gastroenterol. 2002;97:3212-3.
  12. Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies 4th ed. New York: Haworth Herbal Press; 1999.
  13. Ziegler R. Aphanizomenon flow-Aquae (AFA-Algae). A food supplement with dubious health claims. Meeting of the Swiss Study Group for Complementary and Alternative Methods in Cancer. Weiskirchen (Switzerland): November 9, 2001.
  14. Ayehunie S, et al. Inhibition of HIV-1 replication by an aqueous extract of Spirulina platensis (Arthrospira platensis). J Acquir Immune Defic Syndr Hum Retrovirol 1998;18:7-12.
  15. Hayashi T, et al. Calcium spirulan, an inhibitor of enveloped virus replication, from a blue-green algae Spirulina platensis. J Nat Prod 1996;59:83-7.
  16. Petrus M, Culerrier R, Campistron M, Barre A, Rougé P. First case report of anaphylaxis to spirulin: identification of phycocyanin as responsible allergen. Allergy. 2010 Jul;65(7):924-5.
  17. Mazokopakis EE, Karefilakis CM, Tsartsalis AN, Milkas AN, Ganotakis ES. Acute rhabdomyolysis caused by Spirulina (Arthrospira platensis). Phytomedicine. 2008 Jun;15(6-7):525-7.
  18. Moulis G, Batz A, Durrieu G, Viard C, Decramer S, Montastruc JL. Severe neonatal hypercalcemia related to maternal exposure to nutritional supplement containing Spirulina. Eur J Clin Pharmacol. 2012 Feb;68(2):221-2.
  19. Yakoot M, Salem A. Spirulina platensis versus silymarin in the treatment of chronic hepatitis C virus infection. A pilot randomized, comparative clinical trial. BMC Gastroenterol. 2012 Apr 12;12:32.
  20. Savranoglu S, Tumer TB. Inhibitory effects of spirulina platensis on carcinogen-activating cytochrome P450 isozymes and potential for drug interactions. Int J Toxicol. 2013 Sep-Oct;32(5):376-84.

Consumer Information

How It Works

Bottom Line: Blue-green algae has not been shown to treat or prevent cancer, HIV, attention deficit hyperactivity disorder (ADHD), or other serious medical conditions.

Blue-green algae are a natural source of protein and vitamins, which may reduce fatigue. Blue-green algae products usually contain either AFA-algae (Aphanizomenon flos aquae) or Spirulina species, or both. Both may have biological activity. In laboratory experiments, calcium spirulan, an extract from Spirulina, stopped doubling of HIV virus, herpes simplex virus, cytomegalovirus, and influenza virus, but it is not known whether any of these effects would occur in the human body. Other studies showed that spirulina protected lab animals from genetic mutations caused by chemicals and radiation, but again, it is unclear whether these effects happen in humans. In healthy humans, AFA-algae appear to increase blood levels of natural killer cells (a type of immune cell). AFA-algae also show anti-viral and anti-mutation activity in the laboratory.

Spirulina algae also contain high levels of gamma-linolenic acid (GLA), an essential fatty acid that is often able to prevent the accumulation of cholesterol in the body.

Purported Uses
  • As an appetite suppressant
    No scientific evidence supports this use.
  • To treat ADHD (attention deficit hyperactivity disorder)
    There are no data to back this claim.
  • To prevent and treat cancer
    Laboratory studies show that blue-green algae may help protect against DNA mutations. One clinical trial supported the use of blue-green algae for prevention of oral cancer in tobacco chewers.
  • To prevent and treat fatigue
    Scientific evidence is lacking to support this claim.
  • To treat HIV and AIDS
    Blue-green algae show anti-viral activity in the laboratory, but it is unknown whether this effect occurs in humans.
  • To stimulate the immune system
    One study in healthy humans showed that AFA-algae increased blood levels of natural killer cells (immune cells). There is no evidence that such effects help the body fight infections or maintain health.
  • To treat oral leukoplakia (a pre-cancerous condition characterized by thick white patches on the oral mucosa and tongue)
    One clinical trial supported the use of blue-green algae for prevention of oral cancer in tobacco chewers.
  • To treat viral infections
    Blue-green algae show anti-viral activity in the laboratory. Human studies are needed.
Research Evidence

Anemia
This study enrolled 40 volunteers, aged 50 years or older, who had been anemic within the previous 12 months. Participants took a Spirulina supplement and completed a nutritional questionnaire for 12 weeks. Complete cell count (CCC) and indoleamine 2,3-dioxygenase (IDO) enzyme activity were measured at baseline and weeks 6 and 12. Over the 12-week study period, there was a significant improvement in anemia.

Exercise performance
This double-blind, placebo-controlled, counterbalanced crossover study involved moderately conditioned 9 male subjects. After taking a spirulina supplement daily for 4 weeks, each subject ran on a treadmill at an intensity corresponding to 70-75% of their V02 max for 2 hours, and then at 95% VO2 max until exhaustion. Blood samples were drawn at baseline, immediately after, and at 1, 24, and 48 hours post-exercise. Time to fatigue following the 2-hour run was found to be significantly longer after spirulina supplementation compared to placebo.

Diabetes mellitus
This randomized, placebo-controlled study enrolled 37 Korean patients with Type 2 diabetes. Patients received spirulina or placebo for 12 weeks. Spirulina supplementation for 12 weeks was found to significantly lower plasma triglyceride (TG) and malondialdehyde levels, and also showed a tendency to increase plasma adiponectin levels.

Allergic rhinitis
This randomized, double-blind, placebo controlled-study, evaluated the effectiveness and tolerability of spirulina in the treatment of 150 patients with a history of allergic rhinitis. Patients received either spirulina tablets or placebo. Spirulina supplementation was found to significantly improve allergic rhinitis symptoms (nasal discharge, sneezing, nasal congestion, and itching)  compared to placebo. Patient diaries also revealed a statistically significant difference in effectiveness and satisfaction for spirulina compared to placebo.

Patient Warnings
  • Although it is uncommon, the algae used in Spirulina products may be contaminated with toxins from the Microcystis species. For example, anatoxin and saxitoxin are toxic to the nervous system, causing serious side effects like paralysis of the respiratory system.
Side Effects
  • Anaphylaxis (serious allergic reaction)
    Case Report: A 28-year-old man developed acute rhabdomyolysis (severe muscle weakness and pain) after taking Spirulina supplements for one month. His symptoms resolved after discontinuing supplement use.
    Case Report: A day-old baby was hospitalized for generalized seizures associated with hypercalcemia (high levels of calcium in blood), found to be related to the mother's long-term consumption of Spirulina supplements.
  • In rare cases, cyanotoxin (e.g. anatoxin, saxitoxin, microcystins) contamination of may cause liver damage, kidney failure, neurological damage, seizures, respiratory arrest, acute pancreatitis (inflammation of pancreas), and damage to the muscles of the heart.
Special Point

Blue-green algae are used a source of food in some parts of the world. Consumption of this product appears to be relatively safe, as long as it is not contaminated with Microcystin species.

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