Spirulina: A miracle nutritional supplement?


What is spirulina? I found some websites that say it's the best thing in terms of nutrition, but I haven't found a source I really trust.

Dear Reader,

Spirulina is a common type of blue-green algae that grows in warm alkaline water. As you seem to have discovered, many tout the nutritional and curative properties of spirulina, and it has been consumed for centuries by many cultures throughout the world.

As a nutritional supplement, spirulina usually comes in the form of pills, powders, or flakes. It’s a source of many nutrients including protein, carbohydrates, essential fatty acids, B-complex vitamins, vitamin E, and minerals, such as manganese, zinc, copper, iron, and selenium. Among the many benefits touted, some believe spirulina may help boost the immune system, prevent allergic reactions, combat certain viruses, lower cholesterol, protect the liver, fight cancer, and even aid in weight loss. While more research is needed to be able to make firm conclusions about various health benefits for humans, test tube, animal, and even a few human studies suggest that:

  • Immune system support — Animal and test tube studies have shown that spirulina may increase antibody production to improve immunity and ward of various conditions and illnesses.
  • Allergies — Spirulina may act as a sort of antihistamine and prevent the symptoms of allergic reactions, such as hives, swelling, watery eyes, and runny nose, as evidenced by some test tube and animal studies.
  • Viral infections — Some test tube studies suggest that it may be effective against certain viral infections like herpes, HIV and the flu, but more research is needed to determine whether this would have any benefits for humans.
  • High cholesterol — Though some human studies have shown that use of spirulina may lower cholesterol (and in one actually boosted “good” cholesterol) in those with normal to slightly high levels, research findings have been inconsistent.
  • Liver conditions —There is some evidence that spirulina may help protect against cirrhosis and liver damage in those with chronic hepatitis, but at least one study found that liver function was actually compromised due to spirulina use.
  • Cancer — One study in people who used chewing tobacco found that those who used spirulina saw a reduction in precancerous oral lesions in comparison to those in the placebo group. However, more research is needed.
  • Weight loss — Thus far, studies do not show that use of spirulina aids in weight reduction.

While this supplement is likely safe for some, it may not be appropriate for all. People with autoimmune disorders, certain metabolic disorders, pregnant women, and those taking immunosuppressant, anti-coagulant, or anti-platelet medications may want to either avoid use or only use it under the guidance of a health care provider. Side effects from taking spirulina, may include rapid heartbeat, thirst, weakness, nausea, vomiting, stomach pain, liver damage, shock, and even death. Though most spirulina is grown in controlled laboratory conditions, there is a risk of contamination by other potentially harmful microorganisms or heavy metals. It’s recommended to only use spirulina that’s been tested for and free of harmful contaminants.

It’s also good to know that the U.S. Food and Drug Administration (FDA) does not require approval of herbs and nutritional supplements the way it does prescription medications; there is no guarantee of the potency, purity, or safety of products such as spirulina. Due to the potential health risks involved, speaking with a health care provider before taking spirulina is probably your best bet to make sure it's right for you.

Kudos to you for seeking out more information!

Last updated Jul 25, 2014
Originally published Sep 22, 2006

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