Spirulina is a single-celled, blue-green algae touted for its health-boosting potential. It's also promoted as a weight-loss aid, which may attract your attention if you've gained weight due to a sluggish thyroid. You'll find spirulina that's dried and processed into tablets or powder on the Internet, in health-food stores and in supermarkets. Always check with a health-care professional before trying a new supplement.
Theories
Research has not proven spirulina effective for any medical use, including combating excess weight, according to "Collins Alternative Health Guide," by Steven Bratman. Spirulina manufacturers who promote their product as a weight-loss aid sometimes refer to a small, one-month-long study that "proved" its effectiveness, notes Mary J. Shomon in "The Thyroid Diet." Participants, however, lost only small, insignificant amounts of weight, meaning the scientific evidence for this purpose is weak at best, Shomon notes. Also, no scientific evidence backs the claim spirulina is good for weight loss due to its high phenylalanine content, notes Drugs.com.
Properties
Spirulina is a nutrient-dense food, rich in protein, B vitamins, carotenoids, gamma-linolenic acid and chlorophyll, plus minerals like iron, calcium, magnesium, manganese, zinc and potassium. However, it is not high in iodine like other sea-based supplements, including brown kelp. Iodine can help combat an underactive thyroid, but you should only supplement with iodine-rich sea vegetables under a doctor's supervision.
Dosage
No standard dosage for spirulina exists for any purpose, though numerous studies have examined the blue-green algae for an array of possible benefits including enhancing the immune system, reducing eye spasms, relieving premenstrual syndrome and enhancing memory, notes Medline Plus. Studies have looked at doses of 1 to 8.4 grams daily, according to Bratman. Consult a doctor if you want to set a dosage for thyroid-related weight gain. Taking spirulina can lead to nausea or diarrhea. If this occurs, lower your dosage or stop using it. Spirulina that is not contaminated is rated as possibly safe for most people, according to Medline Plus. However, you should avoid spirulina if you have phenylketonuria, an autoimmune disease, or are pregnant.
Considerations
Spirulina has the potential for contamination with many harmful substances, according to Medline Plus. These include liver-damaging substances called microcystins. The maximum safe intake for these hasn't been established, and toxic effects from them may build up in your system over time. Spirulina may also contain a highly toxic substance called anatoxin. Spirulina grown with assistance of fermented animal-waste fertilizers may harbor dangerous bacteria. You also risk contamination from heavy metals like mercury and lead when taking spirulina products. Concerns that spirulina may concentrate radioactive ions found in the environment also exist, notes Bratman.
References
- "The Thyroid Diet"; Mary J. Shomon; 2004
- "Collins Alternative Health Guide"; Steven Bratman; 2007
- "The Healing Power of Vitamins, Minerals and Herbs"; Reader's Digest Association; 1999
- Medline Plus; Blue-Green Algae; November 2010
- Drugs.com: Spirulina
- American Thyroid Association; Thyroid and Weight; 2005
