Chlorella vs. spirulina - the differences and benefits of the two microalgae

You can find them in many bowls, shakes and smoothies - chlorella and spirulina are very popular as superfoods and are said to have many good properties. Chlorella and spirulina can also be bought as tablets. Indeed, the two are real powerhouses. But what exactly makes these algae green superfoods? In this article, you will find out everything you need to know about the two algae, their nutritional properties and possible effects.

Microalgae - the ocean's green superheroes

As the name suggests, microalgae are very small. The single-celled organisms are invisible to the naked eye and, depending on the species, are only a few micrometres to several hundred micrometres in size. Despite their small size, however, algae should not be underestimated. In the waters in which they occur, they are indispensable for the ecosystem. They have amazing adaptive abilities that have enabled them to survive for more than two million years. Whether as a source of nutrients for other marine life or as producers of oxygen for the atmosphere, algae are real power plants.

The most commonly used microalgae as a food or supplement are chlorella and spirulina. Both have a truly impressive profile of nutrients and vital substances, and it is their differences that make them simply unbeatable as a combination. We have taken a closer look at the two.

Chlorella - the tiny green with big power

This algae has a nutrient profile that is really impressive. Carbohydrates, fibre, all essential amino acids and polyunsaturated fatty acids are the macronutrients. In addition, it contains almost all essential vitamins and eight important minerals. Last but not least, there are valuable carotenoids and chlorophyll, the latter in particularly high concentrations. The plants' green elixir of life is said to have many positive properties. Various studies show, for example, a strong anti-inflammatory and antioxidant effect, as well as anti-carcinogenic and anti-genotoxic effects on cells. (1,5)

Studies with Chlorella vulgaris indicate positive effects of the algae on high blood pressure, cholesterol levels, blood sugar levels, insulin resistance, kidneys and detoxification. Chlorophyll has even been linked to weight loss.(1,5) Even if these correlations have yet to be finally confirmed, the added value of chlorophyll cannot be denied. Researchers recommend integrating the green leaves of vegetables, which we usually don't eat, into our meals instead of throwing them away.(5) Of course, this is only recommended for organic vegetables, as otherwise the pesticide load can be very high.

Spirulina - the microalgae that isn't really one

When spirulina was first discovered, it was categorised as an algae, as it was a green organism in water. It was only later that researchers discovered that Arthrospira platensis was not a plant but rather a bacterium. However, as the classification had already been established, it was no longer adapted. This is why spirulina is still referred to as a microalgae today.

It also contains many valuable nutrients, including all essential and non-essential amino acids, fibre, almost all essential vitamins and minerals. Spirulina is particularly high in potassium. It also contains valuable plant substances such as carotenoids and zeaxanthin, which are also associated with many benefits for health. These include, for example, positive effects on vision, liver health, heart and skin. (11,12)

Spirulina algae gets its green-blue colour from a substance called phycocyanin. This is a very powerful antioxidant that binds free radicals and thus protects the cells from oxidative stress. In vitro studies have shown that the cells are protected against heavy metals such as cadmium, mercury and lead. This effect is also attributed to the blue antioxidant(4).

Chlorella & spirulina - the nutritional values

Even though they have a lot in common, the two microalgae differ significantly in some areas. A look at the nutritional values of the two shows that together they cover all the important vitamins and minerals - with the exception of vitamin D and biotin. Spirulina's very high potassium, calcium and magnesium content is particularly striking. These three minerals are essential for muscle function, the nervous system and blood pressure, among other things.

Chlorella scores particularly highly with its very high iron value: just a few grams of the algae could cover the entire recommended daily value. It is also very rich in vitamin A and contains all six B vitamins, which are involved in countless bodily processes.

While spirulina does not contain B5 and B12, chlorella contains both vitamins. On the other hand, spirulina contains a lot of vitamin K, which chlorella does not contain. This vitamin is primarily responsible for blood clotting and bone maintenance. The combination of both algae is therefore ideal for providing you with a comprehensive supply of many important nutrients.

Sources: 6, 7

Discover the power of the sea!

A look at the fat profile shows once again how wonderfully the two microalgae complement each other. Both are rich in unsaturated fatty acids, which are said to have a number of health benefits. Chlorella contains more omega-3 fatty acids, while spirulina contains more omega-6 fatty acids.

Source: 6

Both fatty acids are important for human health, but the balance is very important here. In a Western diet, the intake of omega-6 fatty acids usually clearly predominates, especially due to the widespread use of sunflower oil. In contrast, relatively few foods containing omega-3 fatty acids are consumed, e.g. oily fish or linseed oil. Omega-6 fatty acids have a pro-inflammatory effect, while omega-3s have an anti-inflammatory effect. Now, inflammation is not bad per se, as it is a normal part of wound healing and immune responses.(10) However, a constant excess of omega-6 fatty acids causes a mild, chronic inflammatory state in the body, which can promote various diseases. It is therefore essential to ensure a balance of omega-3 and omega-6 fatty acids(9).

Gamma-linolenic acid or GLA should be mentioned in particular. This is an omega-6 fatty acid that is otherwise mainly found in vegetable oils such as evening primrose, hemp or borage seed oil. Spirulina contains particularly high levels of GLA, which is said to have anti-inflammatory properties. In vitro studies even show that tumour cells die after the addition of GLA(8).

Chlorella & spirulina - the green power duo

Chlorella and spirulina are two really powerful superfoods with which you can easily get an extra portion of nutrients. And if both are a real power booster on their own, the combination of the two is unbeatable. Both algae are ideal as food supplements, as together they contain almost all the important vitamins and minerals, as well as valuable antioxidants. Supplementing with chlorella & spirulina promotes your well-being and gives you an extra daily dose of vital and plant substances. Once again, it's all in the mix!

Sources:

1. Bito T, Okumura E, Fujishima M, Watanabe F. Potential of Chlorella as a Dietary Supplement to Promote Human Health. Nutrients. 2020 Aug 20;12(9):2524. doi: 10.3390/nu12092524. PMID: 32825362; PMCID: PMC7551956. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7551956/
2. Lorenzo K, Santocildes G, Torrella JR, Magalhães J, Pagès T, Viscor G, Torres JL, Ramos-Romero S. Bioactivity of Macronutrients from Chlorella in Physical Exercise. Nutrients. 2023 Apr 30;15(9):2168. doi: 10.3390/nu15092168. PMID: 37432326; PMCID: PMC10181138. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10181138/
3. Gutiérrez-Salmeán G, Fabila-Castillo L, Chamorro-Cevallos G. NUTRITIONAL AND TOXICOLOGICAL ASPECTS OF SPIRULINA (ARTHROSPIRA). Nutr Hosp. 2015 Jul 1;32(1):34-40. doi: 10.3305/nh.2015.32.1.9001. PMID: 26262693. https://www.aulamedica.es/nh/pdf/9001.pdf 
4. Mallamaci R, Storelli MM, Barbarossa A, Messina G, Valenzano A, Meleleo D. Potential Protective Effects of Spirulina (Spirulina platensis) against In Vitro Toxicity Induced by Heavy Metals (Cadmium, Mercury, and Lead) on SH-SY5Y Neuroblastoma Cells. International Journal of Molecular Sciences. 2023; 24(23): https://www.mdpi.com/1422-0067/24/23/17076 
5. Martins T, Barros AN, Rosa E, Antunes L. Enhancing Health Benefits through Chlorophylls and Chlorophyll-Rich Agro-Food: A Comprehensive Review. Molecules. 2023 Jul 11;28(14):5344. doi: 10.3390/molecules28145344. PMID: 37513218; PMCID: PMC10384064. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10384064/
6. Tokuşoglu, Ö. and üUnal, M.K. (2003), Biomass Nutrient Profiles of Three Microalgae: Spirulina platensis, Chlorella vulgaris, and Isochrisis galbana. Journal of Food Science, 68: 1144-1148. https://doi.org/10.1111/j.1365-2621.2003.tb09615.x
7. Andrade LM, Andrade CJ, Dias M, Nascimento CAO, Mendes MA (2018) Chlorella and Spirulina Microalgae as Sources of Functional Foods, Nutraceuticals, and Food Supplements; an Overview. MOJ Food Process Technol 6(2): 00144. DOI: 10.15406/mojfpt.2018.06.00144 
8. Wang X, Lin H, Gu Y. Multiple roles of dihomo-γ-linolenic acid against proliferation diseases. Lipids Health Dis. 2012 Feb 14;11:25. doi: 10.1186/1476-511X-11-25. PMID: 22333072; PMCID: PMC3295719. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3295719/ 
9. Simopoulos AP. The importance of the omega-6/omega-3 fatty acid ratio in cardiovascular disease and other chronic diseases. Exp Biol Med (Maywood). 2008 Jun;233(6):674-88. doi: 10.3181/0711-MR-311. Epub 2008 Apr 11. PMID: 18408140. https://pubmed.ncbi.nlm.nih.gov/18408140/ 
10. Innes JK, Calder PC. Omega-6 fatty acids and inflammation. Prostaglandins Leukot Essent Fatty Acids. 2018 May;132:41-48. doi: 10.1016/j.plefa.2018.03.004. Epub 2018 Mar 22. PMID: 29610056. https://pubmed.ncbi.nlm.nih.gov/29610056/ 
11. Murillo AG, Hu S, Fernandez ML. Zeaxanthin: Metabolism, Properties, and Antioxidant Protection of Eyes, Heart, Liver, and Skin. Antioxidants (Basel). 2019 Sep 11;8(9):390. doi: 10.3390/antiox8090390. PMID: 31514298; PMCID: PMC6770730. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6770730/ 
12. Mrowicka M, Mrowicki J, Kucharska E, Majsterek I. Lutein and Zeaxanthin and Their Roles in Age-Related Macular Degeneration-Neurodegenerative Disease. Nutrients. 2022 Feb 16;14(4):827. doi: 10.3390/nu14040827. PMID: 35215476; PMCID: PMC8874683. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8874683/