made after 45 days, with each child consuming 5 grams
of spirulina per day.
The growth of beneficial intestinal bacteria,
including lactobacillus, appears to be stimulated by
the consumption of spirulina, based on a study of
rats who consumed it as 5% of their diets. The absorp-
tion of vitamin B 1 was also improved.
Cholesterol, serum lipids, and low-density lipopro-
tein (LDL) cholesterol may be lowered by a small, but
significant, percentage by the consumption of spirulina.
One study group of men with high cholesterol took 4.2
grams per day of spirulina, and experienced a 4.5%
decrease in cholesterol after one month.
Spirulina is also thought to be helpful in the treat-
ment of oral leukoplakia, a precancerous condition that
is manifested as white patches in the mouth. It improves
experimentally induced oral carcinoma (cancer in the
mouth) as supported by studies done in animals.
The evidence for the ability of spirulina to pro-
mote weight loss is not very strong. Results have been
mixed, and the phenylalanine content does not appear
to be an appetite suppressant as is sometimes claimed.
Whether other components of the algae are beneficial
for weight loss is uncertain and unproven.
Spirulina has been recommended to alleviate the
symptoms of attention-deficit hyperactivity disorder
(ADHD), although evidence for this indication is lacking.
Spirulina has the highest concentration of ever-
cetin found in a natural source. It is a potent antiox-
idant and anti-inflammatory compound that can be
used to alleviate the symptoms of sinusitis and asthma.
Phycocyanin, the protein that gives spirulina its blue
color, has also been shown to relieve inflammation
associated with arthritis and various allergies.PreparationsOne recommended dose is 3–5 grams per day, but
the amount used may depend on the product, the indi-
vidual using it, and the indication for which it is being
taken.
Spirulina supplements are available in powder,
flake, capsule, and tablet form. These supplements
are generally expensive, and have a strong flavor that
many people find unpleasant.PrecautionsBecause spirulina is sensitive to pollutants in sea
water, it can be used as a biosensor to measure the
toxicity of a given body of water. Unfortunately, this
sensitivity means that spirulina grown in water con-
taminated with heavy metals can concentrate these
toxic substances. Mercury levels are of particular con-
cern. Infectious organisms may also be present and
contaminate harvested algae, so reputable sources of
spirulina should be used.
Phenylketonurics should avoid spirulina due to
the potential content of phenylalanine.
A number of varieties of blue-green algae, includ-
ingAphanizomenon flos-quaeandAnabaena, have been
found to sometimes produce toxins that may affect the
nervous system or the liver.
The potential side effects of spirulina are primarily
gastrointestinal, and include diarrhea, nausea, and vom-
iting. Allergic reactions occur rarely, but can cause
insomnia and anxiety.InteractionsNo interactions of spirulina with foods, conven-
tional medications, or herbs have been documented as
of 2007.Resources
BOOKS
Bratman, Steven, and David Kroll.Natural Health Bible.
Prima Publishing, 1999.
Griffith, H. Winter.Vitamins, Herbs, Minerals & supple-
ments: the complete guide. Arizona: Fisher Books, 1998.
Jellin, Jeff, Forrest Batz, and Kathy Hitchens.Pharmacist’s
Letter/Prescriber’s Letter Natural Medicines Compre-
hensive Database. California: Therapeutic Research
Faculty, 1999.KEY TERMS
Algae (sing., alga)—Any of numerous groups of
one-celled organisms containing chlorophyll. Spir-
ulina is a blue-green alga.
Neuropathy—Condition of weakness affecting the
nervous system.
Phenylalanine—An essential amino acid that can-
not be consumed by people with a metabolic dis-
ease known as phenylketonuria (PKU).
Phycocyanin—A protein found in spirulina that
gives the alga its blue color. Phycocyanin has
anti-inflammatory effects.
Phytochemicals—Nutritional substances con-
tained in plants.Spirulina