8 Benefits of Spirulina From a Nutrition Expert

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Spirulina pops up in many multi-ingredient supplements, from greens powders to immunity boosters. It’s available in powder form, tablets, capsules, liquid, or flakes that you can sprinkle right on your meal.

But what is this “superfood,” exactly? And should you be taking it? Here, I—a functional nutritionist—will discuss all the benefits of spirulina, plus any potential side effects you need to know about.

Read on and see(weed) what spirulina can do for you!

Medical disclaimer: This article is intended for educational and informational purposes only. It is not intended as a substitute for medical advice. For health advice, contact a licensed healthcare provider.

What Is Spirulina?

First, let’s start with the basics. Spirulina (or Arthrospira platensis if you want to call it by its government name) is a blue-green algae. Technically, it’s the dried biomass of cyanobacteria, but that doesn’t sound as appetizing.

RELATED: What Are Super Greens?

Spirulina grows in fresh and saltwater, contains beneficial compounds like vitamins, minerals, carotenoids, and antioxidants, and is a source of protein and a small amount of carbohydrates. Spirulina also contains:

Omega-3 fatty acids
B vitamins
Magnesium
Potassium
Beneficial plant pigments—phycocyanins, chlorella, and beta-carotene—that also give it its blue-green color

8 Potential Health Benefits of Spirulina

From improved exercise performance to decreasing your risk of chronic diseases, spirulina comes with a whole host of health benefits.

1. It’s Loaded with Antioxidants

The antioxidants in spirulina give it its “superfood” designation. Instead of just saying this supplement is loaded with antioxidants, I want to paint the picture for you of how loaded it is.

Antioxidant value is measured with an oxygen radical absorbance capacity (ORAC) assay. The higher the ORAC value, the greater the antioxidant activity.

Spirulina has an ORAC value of over 24,000¹, which is about 10 times as much as blueberries²and 300 more than apples³. To put it another way: The FDA recommends consuming 3,000 to 5,000 ORAC units per day⁴ from plant-based foods. One dose of spirulina, and you’re well beyond that.

But why does this matter? Antioxidants protect your health in a bunch of ways. They can decrease your risk of⁵:

Certain cancers
Neurodegenerative diseases (Alzheimer’s and Parkinson’s disease)
Eye diseases (macular degeneration and cataracts)
Heart disease⁶
Thyroid diseases

They also fight against biological aging in the brain and body, which means you may feel better and think sharper².

2. It May Have Ergogenic Properties

Spirulina’s potential ergogenic properties also come from its antioxidant load, but this one deserves its own callout.

Exercise can create a lot of oxidative stress—a situation in which the body has too many free radicals and not enough antioxidants to neutralize them. You can connect this to muscle damage, fatigue, and drops in performance.

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The antioxidants in spirulina help offset this oxidative stress while also increasing oxygen uptake and improving exercise tolerance⁷. Ultimately, this may help with performance during your workout and post-workout recovery.

There’s also another bucket of research that shows spirulina may improve performance, specifically during high-intensity workouts and resistance training⁸.

3. It May Help Boost Your Immune System

Spirulina may also regulate your immune system⁹, helping you fight off parasites, bacteria, and rapid-onset allergies.

For those who do intense exercise, spirulina may protect against post-exercise immune deficiency¹⁰ by blocking the resulting increase in T-cells⁷.

4. It’s Anti-inflammatory

One of spirulina’s most well-documented benefits is that it’s an anti-inflammatory. Chronic inflammation is connected to¹¹:

Autoimmune diseases, such as rheumatoid arthritis
Heart disease, such as high blood pressure and heart disease
GI disorders, like inflammatory bowel disease, Crohn’s disease, and ulcerative colitis
Asthma
Depression
Type 2 diabetes
Neurodegenerative diseases (Parkinson’s and Alzheimer’s)
Some cancers

Spirulina can also inhibit the release of histamine¹², a chemical released during inflammatory allergic reactions, from mast cells (a type of white blood cell). This can help with allergic rhinitis (hay fever), which causes chronic sneezing, itchy nose and mouth, and runny nose and affects 10% to 30% of the population¹³.

RELATED: Best Probiotic Supplements

In one placebo-controlled clinical trial¹⁴, people with allergic rhinitis were either given a control (placebo) or spirulina for 12 weeks. After the study period, researchers found that a specific allergy marker, interleukin-4, was reduced by 32%.

5. It’s Good for Your Heart

Spirulina has been shown to help improve heart health¹⁵ by reducing blood lipids, like total cholesterol, LDL (low-density lipoprotein) cholesterol, and triglycerides, as well as blood pressure. It also increases the “good” cholesterol¹⁶, or HDL. This can reduce your risk of heart disease.

In one small study¹⁷, researchers gave 4.5 grams of spirulina to 36 men with high blood pressure for six weeks. After the study period, 36% of patients had their blood pressure return to normal, while 50% decreased to prehypertension levels. And that was even without any other changes to their dietary habits or lifestyle during the whole experimental period.

6. It May Help Stave Off Type 2 Diabetes

In addition to lowering cholesterol levels (which can contribute to type 2 diabetes), spirulina may also lower fasting blood sugar levels and postprandial blood glucose (blood sugar concentrations following a meal).

Some older research also showed a significant reduction in A1C levels¹⁸ after supplementing with 2 grams of spirulina per day for two months.

7. It May Help with Weight Loss

I don’t want to oversell this one since no single supplement is going to be the answer to your weight loss prayers. Research shows that spirulina may help reduce body fat¹⁹, waist circumference, and body mass index (BMI), all while helping control your appetite.

That said, the key to weight loss is staying consistent with a healthy diet and lifestyle.

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8. It May Have Anti-Cancer Properties

The jury is still out on this one since studies are mixed, but spirulina has also been connected to decreased risk of certain types of cancers.

It may also improve immune function after chemotherapy²⁰, but always make sure to get the all-clear from your oncologist.

Potential Side Effects of Spirulina

Spirulina supplementation is not without its risks, though, but the chances of side effects are slim. When they do happen, the most common potential spirulina side effects²¹ are:

Diarrhea
Bloating
Upset stomach
Flatulence
Edema
Headache
Muscle pain
Facial flushing
Sweating

That said, like any dietary supplement, you want to make sure you’re choosing one with a clear formula that’s been third-party tested.

Low-quality spirulina powders can be contaminated with heavy metals²², microplastics, and/or microorganisms (bacteria, viruses, fungi). They can also contain microcystins, toxins produced as a result of the living algae trying to defend themselves against predators.

Most reputable spirulina supplements have levels of toxins below the level that would be harmful to healthy adults²³. You still want to avoid high doses²⁴, though, as this can make toxicity more likely.

Additionally (and again, like all supplements), spirulina isn’t for everyone. The microalgae is rich in all amino acids, including one called phenylalanine. If you have a condition called phenylketonuria, you should avoid spirulina since your body can’t break down phenylalanine.

Spirulina can also interfere with the way your body uses vitamin A and vitamin E and may interact with some diabetes medications.

Mount Sinai Hospital²⁵ also recommends avoiding spirulina if you have an autoimmune disease, like multiple sclerosis, rheumatoid arthritis, or lupus, since it could potentially make these conditions worse.

If you’re pregnant or breastfeeding, you should also talk to your doctor before taking spirulina.

Benefits of Spirulina: Final Thoughts

Because of its antioxidant effects and anti-inflammatory properties, spirulina is a notable health food. It may reduce the risk of heart disease, type 2 diabetes, and certain types of cancers. It may also improve exercise performance and recovery, especially for those who do high-intensity workouts.

More isn’t better, though—stick to the recommended doses, and you’ll be more likely to reap the benefits without the potential drawbacks.

Benefits of Spirulina: FAQs

What does spirulina do for your body?

Spirulina provides antioxidants, vitamins, minerals, and essential amino acids, which have a protective effect on your health. It may also help reduce inflammation, lower blood lipids and blood sugar, and generally protect your body from biological aging.

Is it safe to take spirulina everyday?

Yes, it’s safe to take spirulina every day. Just make sure you’re sticking to the recommended doses. While the National Institutes of Health (NIH) hasn’t given an official upper limit for spirulina, the American Nutrition Association recommends no more than 10 grams of spirulina per day²⁴.

Can spirulina reduce belly fat?

There’s some evidence that spirulina can help reduce body fat, waist circumference, and body mass index (BMI)¹⁹. But it’s not the sole answer to getting rid of belly fat—you need to dial in your nutrition and exercise, too.

RELATED: How To Lose Body Fat

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any diseases.

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Lindsay Boyers, CN

Lindsay Boyers is a functional nutritionist, writer, and editor with over a decade of experience in online media. She's written 14 books and hundreds of articles on fitness, wellness, nutrition, and lifestyle. Lindsay holds certifications in holistic nutrition, functional nutrition, and professional food safety, as well as a B.S. in food in nutrition.

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