Spirulina is a blue-green algae best known to hippies but not as understood in the mainstream. It gained popularity when NASA used it as a dietary supplement for astronauts in space and has since become a go-to supplement for various health issues.

Spirulina contains vitamin B12, vitamin A and is high in iron, but it does have one big drawback: It doesn't taste very good, in fact some have even likened it to pond scum (though we question how they know what pond scum tastes like.) It has been touted as an energy enhancer and immunity booster, and it also increases healthy lactobacillus in the intestine, enabling the production of vitamin B6, which helps in energy release. Despite this, clinical trials showed there is no significant difference between spirulina and a placebo for increasing energy. Add to that, you may need to take large amounts for it to be of any effect.

The algae grown in warm, alkaline waters, is available dried and freeze-dried and comes in supplement form as pills, powder or flakes. Most spirulina in the U.S. is grown in labs, but the algae can be contaminated with toxic substances and absorb heavy metals from the water where it is grown, so it’s best to buy only from trusted brands.

This is one reason Martina Cartwright, PhD, RD, an independent biomedical research medical regulatory affairs consultant and author in Scottsdale, Arizona, is not a proponent. "There are other less expensive sources of these key nutrients, and that's why I'm not a fan. Plus there have been safety issues with contaminants."

"It is high in protein, but no more so than dairy or lean meat," she says. "It may be a good source of B12 and certain healthy fats, but due to growing differences (soil/water nutrients, etc.), the source of B12 is not reliable."

There are some benefits

Spirulina in tablet and powdered forms

Spirulina in tablet and powdered forms. (Photos: Lukas Gojda/Shutterstock)

However, the algae has been used as a source of protein and vitamin supplements for years without side effects. It is rich in chlorophyll, and like plants, gets its energy from the sun, making it a popular supplement for vegetarians and vegans. Recent clinical studies have suggested it has antiviral, anti-inflammatory and anti-allergic effects.

In a recent randomized, double-blind placebo-controlled trial, people with allergic rhinitis were fed with placebo or spirulina daily for 12 weeks. The study showed that people who took the high doses of spirulina significantly reduced allergen levels in allergic rhinitis.

"I like using spirulina as a protein-rich superfood with my clients," says Zoë Keller, a holistic health coach. "It works well for people who need to re-mineralize their body and boost their daily nutrient intake (which is most people eating the Standard American Diet)."

Spirulina does have nutritional value, including:

  • 60 percent protein, as well as many important amino acids
  • Antioxidants (ORAC score four times higher than blueberries; ORAC is a way to measure the total antioxidant capacity of a food. )
  • Essential minerals, such as calcium and iron
  • Chlorophyll, which helps remove toxins from the body and boost the immune system
"Spirulina powder can easily be added to green smoothies, but it does have a strong flavor," says Keller.  Supplements are a great option for people who can't tolerate the taste.  If you want to try spirulina, Keller suggests following the package instructions for dosing, but recommends starting slowly, given spirulina's strong detoxification action.

In a study on spirulina's cholesterol lowering effects, 15 male volunteers took the algae for eight weeks and showed a significant reduction in their cholesterol levels.

Another study by the Department of Aquataculture in Taiwan, found that when a group of white shrimp were exposed to seawater containing spirulina, before transferring them to seawater with a pH level of 6.8, the shrimp exposed to spirulina showed a faster recovery rate than a control group not exposed to the algae.

Spirulina in powdered and forms, and mixed as a drink

Spirulina in powdered and forms, and mixed as a drink.

"Some claim it helps children with behaviors like ADD as well as other conditions like arthritis," says Cartwright. "It is touted as a 'cure all.'" Historically, however, the scientific evidence is lacking. It's also expensive.

Despite mixed reviews, spirulina appears safe when bought from a reputable brand. If you're pregnant or breastfeeding, talk to your doctor before trying it. People with autoimmune diseases like multiple sclerosis, rheumatoid arthritis or lupus should avoid the algae as it could overstimulate the immune system. In addition, those with the metabolic condition PKU should also avoid it because they may not be able to metabolize its amino acids properly. Keller recommends taking supplements only under the supervision of a knowledgeable health professional.

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