SPIRULINA are microorganisms classified among bacteria.
They are part of CYANOPHYCEAE or BLUE ALGAE but according to botanists they are not real algae.
Their cellular structure and composition, their mode of reproduction and their physiology characterize them as photosynthetic bacteria living mainly in colonies.
They are microscopic, green or blue-green filaments, most often spiral and unbranched.
CYANOPHYCEAE (which include spirulina and arthrospira) are small, very old organisms (perhaps present on Earth for more than 2.5 billion years) which are probably responsible for the transformation of the Earth's atmosphere by oxygen enrichment , with the major consequences of oxidation of terrestrial minerals and the appearance of the ozone layer at high altitude which, partially blocking ultraviolet radiation, will allow life to develop outside of water.
Cyanophyceae are found everywhere on Earth, in water, on soils and in the most extreme climates.
Now Spirulina platensis and Spirulina maxima are integrated by specialists in the genus ARTHROSPIRA.
However, in everyday language we speak more often of SPIRULINA than of ARTHROSPIRA.
The 2 SPIRULINA mentioned are the best known but there are about thirty other species of spirulina (spirulina or arthrospira).
These two spirulina naturally grow in freshwater lakes with "extreme" physicochemical conditions (high temperature, high content of sodium carbonate and bicarbonate) where they have few competitors.
Spirulina (Arthrospira) platensis is found in the "natron" lakes of sub-Saharan Africa (especially in Chad).
Spirulina (Arthrospira) maxima occurs in Central America, for example in Lake Texcoco in Mexico.
Local people have been harvesting and consuming them for a very long time, now they are cultivated artificially in many countries.
Their interest is mainly dietary, as a food supplement, but some spirulina extracts have interesting pharmacological properties (strengthening immunity, protection of the nervous system, antioxidant and anti-inflammatory).
CHEMICAL COMPOSITION AND PROPERTIES
Spirulina contain proportionally more protein than meat, between 50 and 70% of their dry weight.
The main amino acids (including essential amino acids) are present and perfectly assimilable.
Spirulina contain little lipids, 3 to 4% of the dry weight, but with fatty acids that are interesting from a dietetic point of view (linoleic acid, gamma linolenic acid.)
About 15% of dry weight.
Spirulina do not have a cellulose wall (unlike higher plants) which facilitates their digestion by the body.
A high molecular weight carbohydrate fraction, but soluble in water (between 0.5 and 2% of the dry weight), called "immulina", would have immunostimulating power.
About 6% of the dry weight, in particular calcium, iron, zinc, phosphate, magnesium, sodium, but also heavy metals or potentially toxic elements if they are present in a large in a polluted culture medium, lead , arsenic, cadmium, mercury, selenium, iodine.
- VITAMINS AND PROVITAMINS
Mainly yellow-orange carotenoid pigments (PROVITAMIN A): carotene, beta carotene.
The majority of "GROUP B VITAMINS". However, Japanese researchers have reported that some of the cyanocobalamin compounds present in these spirulins do not have the vitamin action of the real vitamin B 12.
A small amount of VITAMIN E (tocopherol) and VITAMIN K.
- OTHER interesting COMPOUNDS: pigments which capture light (apart from the carotenoids already mentioned): PHYCOCYANIN (blue pigment), certain chlorophylls (green pigment).
These compounds are anti-oxidants (scavenge free radicals) and can therefore reduce acute and chronic tissue inflammation.
SPIRULINA: NUTRITION AND DIETARY SUPPLEMENT
Only populations near lakes where spirulina (arthrospira) develop naturally and are abundant can feed on them.
These cyanophyceae float and accumulate on the edges of the body of water, sometimes they are harvested by "skimming" the water.
The spirulina are then dried (for their conservation) but are also eaten fresh.
Spirulina are not toxic but, in nature, they can mix with other blue algae which can eventually release toxins (neurotoxins or carcinogenic toxins).
Containing little lipids, spirulina do not bring many calories to the body (they are not nourishing), but on the other hand they are a very important source of assimilable proteins and vitamins especially for populations isolated the AFRICAN SAHEL or from 'other quasi-desert regions where they can be harvested.
Since their "discovery" in the middle of the XXth century, their controlled cultivation (monoalgal) has been improved in open-air basins or biological reactors.
It is now possible to buy spirulina powder or spirulina tablets both in pharmacies and on the internet.
It is a DIETARY SUPPLEMENT (3 to 10 g per day), providing provitamins A, minerals, trace elements and proteins, but not yet a real food because the cost of production remains too high.
We can consume spirulina:
- when we are in good health,
- but also to regain tone following an infectious disease,
- to fight against the effects of anti-cancer treatments,
- to slow down aging ( intake of easily digestible protein is important in the elderly).
Spirulina can also cure children suffering from malnutrition and vitamin deficiency (areas of conflict or natural disasters, displaced people).
SPIRULINA IN PHYTOTHERAPY
STIMULATION OF IMMUNITY, FIGHT AGAINST VIRAL INFECTIONS
Some studies suggest that a fraction of the high molecular weight polysaccharides present in spirulina reinforces the activity of cells which ensure the defense of the organism (immolina fraction).
Regular intake of around 10 to 20 g of spirulina powder improves the general condition of HIV carriers (dietary effect and immune stimulation in these immunocompromised patients developing AIDS)
PROTECTION OF THE CENTRAL NERVOUS SYSTEM
Spirulins are offered to slow down certain neurodegenerative diseases (Parkinson's disease) and improve recovery following a stroke.
SPIRULINA IN DERMATOLOGY
"Thermal mud" partly owes its properties to cyanophyceae (blue algae) which can develop in hot thermal waters saturated with minerals.
For this reason, spirulina extracts are sometimes present in dermatological preparations:
- for their antioxidant and therefore protective power,
- to fight against chronic infections , or to accelerate the healing of infected wounds or chronic ulcers,
- to prevent cancerous degeneration of irritated or damaged skin (sun, chemicals known to induce skin cancer).
MEDICAL RESEARCH ON PHYCOCYANIN
Phycocyanin is of interest to pharmacologists:
- for its antioxidant power,
- for its ability to increase the effectiveness of anticancer treatments (chemotherapy and radiotherapy).
Studies mainly in vitro show a significant increase in the disappearance (apoptosis) of different types of cancer cells (in culture) in the presence of phycocyanin.
To my knowledge, there is not yet any use of phycocyanin in practical medicine, phycocyanin has to be "encapsulated" and then brought as close as possible to cancer cells, but it is a promising therapeutic avenue.
The spirulina that we are quoting in this page like very sunny, very hot waters rich in carbonates (commonly called soda crystals) and sodium bicarbonates.
To obtain a good yield in culture, it is necessary to recreate these conditions which is difficult in the open air in temperate countries except in summer in regions with a Mediterranean climate, or in greenhouses for a few more months.
However, algologists have been able to isolate strains of spirulina that require less heat.
The cultivation of planktonic microorganisms is much more demanding and technical than that of terrestrial plants:
- risk of pollution by other competing algae species,
- presence of "predators" (crustaceans, protozoa, viruses),
- need to harvest the algae at a specific time of their growth and regularly renew the strain of algae after a few cultivation cycles, etc.
However there are many "cultivators" of spirulina in the world (including in France).
It is even perfectly possible to cultivate spirulina at home, we replace the goldfish aquarium by spirulina kits .
The culture medium in which the spirulina is inoculated requires a supply of "fertilizer" (phosphate and nitrate).
Nitrates are expensive and can partly replace with urea, but some companies, especially Chinese, which are embarking on large-scale spirulina crops, are trying to use the effluents from pig farms as fertilizer,
but be careful. , in this case the risk of bacteriological and chemical pollution of the spirulina becomes significant.
ALGAE AS FOOD
We have been trying to develop cultivation of microscopic algae for food use since the mid-twentieth century, especially Chlorella (a microscopic green algae).
Cycles are short, surface requirements limited, productivity high, but chlorella is difficult to digest because of its cellulose wall.
The "discovery" of spirulina has revived this human dream of food self-sufficiency above ground.
Some detractors of the cultivation of spirulina believe that many cultivated or spontaneously growing plants provide as much protein, vitamins and minerals as spirulina. Let us cite for example: nettles, amaranths, spinach, leaves of moringa, cassava, certain taros (non-exhaustive list).
But countries with an arid and hot climate, with a lot of sunshine (Africa, Middle East) see in the cultivation of spirulina on a large scale the possibility of a profitable crop which would bring them the possibility of a food autonomy at least in protein..
SPIRULINA DIETARY AND MEDICINAL FOOD
The spirulina Arthrospira platensis and Arthrospîra maxima, are blue algae (photosynthetic bacteria), originating in Africa and America.
These are traditional foods in certain limited areas of Africa but can now be grown on a large scale.
Spirulina contain a high percentage of perfectly assimilable proteins, vitamins, provitamins and mineral salts.
It is a dietetic and rebalancing food.
Spirulina contain immunostimulating, neuroprotective and antioxidant compounds.
Copyright 2022 : Dr Jean-Michel Hurtel