Spirulina is a blue-green algae known as one of the richest foods on the planet. Its many abilities also seem linked to the composition of spirulina which is unusual. But what is it really? What does spirulina contain? What are the nutritional values ​​of spirulina?

The proteins

Present in spirulina , proteins are the building blocks of muscle , it is the most represented element in the body after water (nearly 62% of the body weight in water and 17% in proteins). They are also the basis of many metabolic processes (immunity, cellular repair, etc.) and constitute a large number of enzymes and hormones .

Each protein is made up of a sequence using 20 amino acids on the same principle that a word uses a sequence of 26 letters.

These amino acids present in protein can be supplied through food or manufactured by the body . However, some cannot be produced by the body, these are called essential amino acids , of which there are 8 in adults and 10 in children. In the common diet, animal proteins provide all these essential amino acids while plant proteins are individually incomplete.

The missing amino acid(s) are then called “limiting factors” because they limit the production of proteins using this amino acid. In the long term, a deficiency in essential amino acids causes the same effects as a protein deficiency. This is why it is important to vary the sources of plant proteins in order to benefit from all these amino acids.

The composition of spirulina is very rich in proteins ( 60-70% of its dry weight) [1] of high biological value. It contains all the essential amino acids for both adults and children. The spirulina membrane dissolves easily under the effect of gastric acidity, which guarantees the proper assimilation of these 20 amino acids.

Lipids

The composition of spirulina also contains lipids. Lipids make up nearly 14% of our weight: they are the architects of our cell membranes . The lipids are organized in a double layer in order to isolate the interior of the cells from the environment in which they are immersed. The nature of these lipids modifies membrane flexibility and influences the quality of message transmission between cells.

Lipids are also found in the nervous system (the brain contains 60%). They create a sheath around the nerves, which allows information to be conducted much more quickly.

Finally, lipids contained in adipose tissue play a role in energy storage and thermal regulation .

Spirulina lipids represent 2 to 4% of its total weight. They present an optimal balance between omega-3 and 6, guaranteeing good cardiovascular health. Spirulina is particularly rich in essential fatty acids with a high level of alpha-linolenic acid (ALA) and gamma-linolenic acid (GLA)[2] which participate in hormonal synthesis . GLA is only found in borage, evening primrose and blackcurrant oils as well as in breast milk and spirulina. The subclass of dihomo gamma-linolenic acid (DGLA) is, for its part, only present in spirulina and breast milk. These fatty acids are provided by food or transformed by the body from omega-6.

Carbohydrates

Carbohydrates provide the direct energy supply of a food. They represent 1.5% of body weight. When consuming glucose, part is immediately integrated into the cells thanks to the intervention of insulin, the other part is stored in the liver and muscles in the form of glycogen, an energy reserve .

Present at approximately 20% in dry spirulina, its carbohydrates are mainly provided in the form of glycogen and rhamnose. Glycogen is the storage form of carbohydrates in the body that can be quickly mobilized . These two sugars cause very little variation in blood sugar levels and minimally mobilize insulin and therefore the pancreas.

Vitamins

Components of spirulina, vitamins are responsible for metabolism , development and cellular protection . Apart from vitamin D which is synthesized by the skin, all vitamins must be provided through food . Currently 13 of them are known but their roles have not yet been fully identified. Some of them can be stored in the body's fatty tissues or in the liver and muscles (vitamins A, B9, B12 D and E).

The most interesting vitamins present in spirulina are:

• Vitamin A :
  In the form of β-carotene (precursor of vitamin A). With spirulina, the intake of vitamin A adapts to needs; (pathological) hypervitaminosis is therefore impossible – unlike supplements containing vitamin A – and not its precursor. Vitamin A contributes to the normal functioning of the immune system
• Vitamin B1 :
  Spirulina is the second source of vitamin B1; only brewer's yeast is richer.
• Vitamin B2 :
  Spirulina is the fourth food richest in vitamin B2.
• Vitamin B12 :
  Spirulina contains two forms of vitamin B12, cobalamin and pseudo-cobalamin, each with defined roles.
• Vitamin D :
  Spirulina is the most important plant source of vitamin D.

The minerals

Minerals represent 6% of body weight. They are present in very large quantities mainly in the skeleton, and must be supplied through the diet . The most interesting minerals in spirulina are:

• Calcium :
  Spirulina contains as much calcium as whole milk
• The iron :
  Spirulina contains highly assimilable iron.
• Magnesium :
  Spirulina contains a high level of magnesium, 10% higher than the content of dark chocolate 70% cocoa.

Pigments

Spirulina is a blue-green microalgae containing a large number of pigments.

• Phycocyanin :
  It is the noblest element of spirulina.
• Carotenoids :
  β-carotene is part of this family of pigments and is particularly well represented in Spirulina which contains 20 to 25 times more than carrots.
• Chlorophyll :
  Pigment of photosynthesis , it is present at 1% in spirulina.

Thus, given the quantity and quality of the components of spirulina, it is possible to say that it has a particularly interesting and complete nutritional composition.

Take a moment to discover all our dedicated food supplements: Spirulina food supplement .

Sources

[1] Teuling E. & al. (2017) Comparison of Protein Extracts from Various Unicellular Green Sources. J Agric Food Chem. 2017 Sep 13;65(36):7989-8002. doi: 10.1021/acs.jafc.7b01788.

[2] Otles S. & al. : Fatty acid composition of Chlorella and Spirulina microalgae species. J AOAC Int. 2001 Nov-Dec;84(6):1708-14.