Health Benefits Of Spirulina


If you’ve ever tried to make variations of healthy smoothies or a fancy acai bowl, chances are you’ve used spirulina powder. But aside from providing a vibrant colour to your snack, do you know about the nutrient content of this powder? Where is it derived from? Why does it come in different colours? 

About spirulina

Cyan means blue, and spirulina comes from a group of organisms called Cyanobacteria or blue-green algae. Algae are the green-coloured growth you can find in ponds and wells in tropical and subtropical climates. They grow in alkaline and salty water. As the nutraceutical and fitness industry is booming, the alga has found its way on our plates (and bowls)- because it’s not only rich in macros (protein, essential fats) but also has bioactive compounds (like phenols, PUFA, and phycocyanins) which have been proven to be anti-inflammatory.

The most common commercially produced spirulina are S.platensis and S.maxima. Seaweed farming is picking up in many developing countries as it does not require land, expensive equipment, and fertilizers, and can generate more biomass per hectare in comparison to vascular plants.1 

Health benefits of spirulina

Anti-obesity/Weight Control

Consuming doses of around 1-19g per day mediates:

  • The feeling of satiety
  • Reduced fat deposition in the liver and formation of fat cells
  • Suppression of appetite by a molecule called phenylalanine
  • Inhibits oxidative stress or the triggers that initiate inflammation in the body2
  • Has a direct impact on weight and waist circumference when used for 12 weeks and on BMI if used for longer periods3

Improving GUT health

There is a term called dysbiosis for the imbalance in the amount of good versus bad bacteria in the gut. We naturally need a healthy amount of good bacteria (like lactobacilli and bifidobacter) to combat the bad bacteria (like Bacteroids and Clostridium). Giving spirulina to the gut essentially amounts to feeding the good bacteria (in the form of simple sugars like oligosaccharides), which helps them flourish over the bad ones.4

This fact can be potentially used to fortify probiotic extracts and benefit individuals with gut problems like inflammatory bowel disease (or IBD) and ulcerative colitis (UC). Additionally, it was found that the alcoholic extract of spirulina has the highest content of compounds that reduce inflammation (phenols) and also inhibit the growth of bad bacteria by a higher amount. 

Improving immunity

Carbohydrates (or carbs- as they are called in recent times) have been moulded by the diet culture to be viewed as harmful and obesity-inducing. In fact, carbohydrates are one of the three macronutrients along with protein and fat, and they need to be consumed in their specified quantities. The presence of sugars like glucose and polysaccharides in spirulina gives it the ability to have anti-oxidant and anti-inflammatory properties.5

To summarise, the immunity-boosting nature of spirulina platensis:

  • Activates immune cells like T cells, B cells, and NK cells
  • Polysaccharide compounds boost these properties
  • Increases antibodies

Blood pressure lowering effect

Molecules like C-phycocyanin along with high potassium in spirulina help in lowering both numbers on the blood pressure reading (systolic and diastolic). Furthermore, it also:

  • Prevents clot formation by preventing the clot particles from sticking to one another.
  • ACE inhibitor drugs are used as blood pressure-lowering agents. Natural ACE inhibitors have been found in spirulina6
  • C-phycocyanin pigment helps lower blood cholesterol

Cholesterol-lowering effect

  • Phenols in spirulina help in combating free radicals- which are molecules that start inflammation in the body
  • Helps lower the bad cholesterol (triglycerides and LDL cholesterol) and increase the good cholesterol (HDL)7
  • Spirulina contains niacin- a vitamin that corrects any imbalance in blood lipids
  • Inhibits an enzyme called lipase which reduces fat absorption
  • When consumed as a nutraceutical supplement it can decrease the risk of heart-related events associated with high cholesterol in the body8

Control of diabetes

Due to the bioactive compounds in spirulina, it is a good supplement for diabetics. It is beneficial in reducing blood cholesterol, blood sugar and also fighting inflammation. This helps in combating diabetes-related changes in the pancreas at a cellular level. This also makes it ideal for diabetes-related complications.9

Anti-cancer properties

Indeed, with a rich source of antioxidants, it is a potential supplement for cancer patients. It is the pigment molecules - namely, C-phycocyanin, cryptoxanthin, zeaxanthin, and others which have the best antioxidant properties. In addition, immulina sugar strengthens our immune cells to fight against cancer cells. 

With these in mind, studies were conducted on different cancer cell lines- like liver, colon, and chronic myeloid leukaemia (K562) cells with different concentrations of spirulina extract and the result inspired the use of blue-green algae as a nutraceutical anti-cancer drug.10

Cardioprotective effects

It is well known that heart disease is the leading cause of global mortality these days. Leading a stressful and sedentary lifestyle, along with high cholesterol and diabetes are the major contributors to worsening heart health. Consuming spirulina helps with these lifestyle disorders as mentioned above, along with fighting inflammation (or oxidative stress) in the body.

Nutrients we can get from spirulina

In terms of dry weight, spirulina contains up to 56% of protein, 12% carbohydrates, 6% fats, and 10% fibre. 



It contains 15-25% of carbohydrate content, of which most are simple sugars which are easier to digest for the older population and individuals with digestion problems.

Lipids or fats

We have all surely heard of omega oil supplements. The essential oils are derived from fish, which in turn get it from feeding on algae. Due to potentially toxic compounds and oxidative instability of oils from fish, extraction from algae has been explored. These algae have the four essential cardioprotective fatty acids - eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), alpha-linolenic, and docosapentaenoic acid. After human breast milk, spirulina is the only source rich in essential fatty acids. 


Proteins are made up of amino acids. Some amino acids are produced by the body (non-essential) and others are to be consumed from outside (essential). Foods rich in protein are classified as complete if they contain all amino acids and are easily absorbed by the body. Spirulina contains around 60-70% of its dry weight as protein, in comparison to beef which is around 22%.11  This is why it has gained importance in the modern diet and nutrition industry. Many children suffer from protein-energy malnutrition (or PEM) and the addition of this superfood in their rehabilitation has been proven to benefit them faster than breastmilk. This is because spirulina is easily absorbed (as it is coated with simple sugars) in comparison to utilising enzymes for breaking down plant proteins.

How to include spirulina in our diet?

The algae is now commonly found in powdered form, but capsules, tablets and oils are the other forms of consumption.

Because of its rich colour, it can also be incorporated into many desserts as a healthier substitute for edible food dyes. Biscuits, cookies and cakes can be fortified with spirulina for both protein content and aesthetic value.

Adding 1-2 tbsp of spirulina to pasta dough can make your regular mac n cheese more nutritious.

S. platensis can be added to ice creams at a concentration of 1-2% to achieve the ideal physical and sensory characteristics.

The addition of the algae to fermented products showed that it increased the lifespan of the starter organisms that were used for fermentation.12

Can easily replace unhealthy salad dressings if mixed with some mustard, lemon and olive oil.

How much is enough?

According to USDA, it can be taken in the daily diet up to 1 tablespoon or 7g per day. If taken at higher quantities, there is no known side effect. Moreover, many quantitative studies show that the beneficial effects were greater at higher concentrations.

Side effects and how much to consume

Spirulina is safe for human consumption, classified under the category “Generally Regarded As Safe” by the FDA. It has no toxicity effects or side effects at both acute or chronic doses- meaning if it is given as a massive single dose or small doses over a long period.13


Spirulina is a part of the blue-green algae family that has received much attention from the pharmaceutical and scientific community due to its densely packed nutrient content. Several studies on human and animal models have strengthened the beliefs as it is found to have biological and ecological benefits. As it is highly resistant (to pH and temperature), a large amount of biomass can be produced at a commercial scale without the use of chemicals. If consumed, it can provide not only important macronutrients but also essential bioactive compounds such as polyunsaturated fatty acids, vitamins, carotenoids and many others. Since the powders come with bright pigments, it can be easily incorporated into our diet (1-2 tbsp per day) in the form of bakery products and smoothies without any risk of toxic effects.


  1. Fogg GE, Thake B. Algal cultures and phytoplankton ecology. Univ of Wisconsin Press; 1987
  2. Moradi S, Ziaei R, Foshati S, Mohammadi H, Nachvak SM, Rouhani MH. Effects of Spirulina supplementation on obesity: A systematic review and meta-analysis of randomized clinical trials. Complementary therapies in medicine. 2019 Dec 1;47:102211.
  3. Zarezadeh M, Faghfouri AH, Radkhah N, Foroumandi E, Khorshidi M, Rasouli A, Zarei M, Mohammadzadeh Honarvar N, Hazhir Karzar N, Ebrahimi Mamaghani M. Spirulina supplementation and anthropometric indices: A systematic review and meta‐analysis of controlled clinical trials. Phytotherapy Research. 2021 Feb;35(2):577-86.
  4. Hadebe N. Isolation and characterization of prebiotic oligosaccharides from algal extracts and their effect on gut microflora (Doctoral dissertation).
  5. Ravi M, De SL, Azharuddin S, D Paul SF. The beneficial effects of Spirulina focusing on its immunomodulatory and antioxidant properties. Nutrition and dietary supplements. 2010 Jul 30:73-83.
  6. Mohan A, Misra N, Srivastav D, Umapathy D, Kumar S. Spirulina, the nature’s wonder: A review. Lipids. 2014;5:7-10.
  7. Huang H, Liao D, Pu R, Cui Y. Quantifying the effects of spirulina supplementation on plasma lipid and glucose concentrations, body weight, and blood pressure. Diabetes, metabolic syndrome and obesity: targets and therapy. 2018 Nov 14:729-42.
  8. Wang Y, Ocampo MF, Rodriguez B, Chen J. Resveratrol and Spirulina: Nutraceuticals that Potentially Improve Cardiovascular Disease. J Cardiovasc Med Cardiol. 2020;7(2):138-45.
  9. Gheda SF, Abo-Shady AM, Abdel-Karim OH, Ismail GA. Antioxidant and Antihyperglycemic Activity of Arthrospira platensis (Spirulina platensis) Methanolic Extract: In vitro and in vivo Study. Egyptian Journal of Botany. 2021 Apr 1;61(1):71-93.
  10. Matos J, Cardoso CL, Falé P, Afonso CM, Bandarra NM. Investigation of nutraceutical potential of the microalgae Chlorella vulgaris and Arthrospira platensis. International Journal of Food Science & Technology. 2020 Jan;55(1):303-12.
  11. AlFadhly NKZ, Alhelfi N, Altemimi AB, Verma DK, Cacciola F, Narayanankutty A. Trends and technological advancements in the possible food applications of spirulina and their health benefits: a review. Molecules [Internet]. 2022 Jan [cited 2023 Mar 19];27(17):5584.
  12. Varga L, Szigeti J, Kovács R, Földes T, Buti S. Influence of a spirulina platensis biomass on the microflora of fermented abt milks during storage(R1). Journal of Dairy Science [Internet]. 2002 May 1 [cited 2023 Mar 19];85(5):1031–8.
  13. Salmeán GG, Castillo LH, Chamorro-Cevallos G. ‘Nutritional and toxicological aspects of Spirulina (Arthrospira). Nutrición hospitalaria: Organo oficial de la Sociedad española de nutrición parenteral y enteral. 2015;32(1):34-40.
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Tejal Parmar

Dr. Tejal Parmar is a physician with a flair for medical writing working in the oncology emergency department. Having worked in both rural and urban clinical setting, as well as in the non-clinical role as a Medical Science Liaison, she can write while striking a delicate balance in scientific accuracy and plain language. She is currently working for her medical registration to practise in the UK.

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