By Genene Tefera, DVM, PhD
Microbial Genetic Resources Department, Institute of Biodiversity Conservation
Addis Ababa, Ethiopia, January, 2009
This scientific article, which Terera was gracious enough to let us reproduce, is an excellent starting point in learning more about this blue-green algae, as it covers every aspect of spirulina.
The name spirulina comes from a Latin word meaning tiny spiral. Spirulina is microscopic and spiral-shaped Spirulina is a genus of the phylum Cyanobacteria which are classified as bacteria. Even though it is single-celled attaining sizes of 0.5 millimeters in length, which makes some individual spirulina cells visible to the naked eye. There are several species of spirulina. The ones most commonly used in nutritional supplements are Spirulina platensis and Spirulina maxima.
Spirulina has been on the planet over 3 billion years. It still grows wild and abundantly around the world in very alkaline, mineral-rich, largely pollution-free, soda lakes. Spirulina is not sea bacteria. However, the fresh-water ponds and lakes spirulina favors are notably more alkaline, in the range of 8 to 11 pH, than ordinary lakes and cannot sustain any other forms of microorganisms. This water is too salty (up to pH 11) to support fish, to use for growing terrestrial crops or for drinking. But it is perfect for growing Spirulina. Spirulina thrives in very warm waters of 32 to 45 0C (approximately 85 to 112 0F), and has even survived in temperatures of 60 0C (140 0F). Certain desert-adapted species will survive when their pond habitats evaporate in the intense sun, drying to a dormant state on rocks as hot as 70 0C (160 0F). In this dormant condition, the naturally blue-green bacteria turn a frosted white and develop a sweet flavor as its 71% protein structure is transformed into polysaccharide sugars by the heat. In fact, the hotter it gets and the more the mineral salts concentrate as water evaporates the faster and more prolifically Spirulina grows!
Ironically and significantly, the most fertile valley of soda lakes with heavy Spirulina growth today lies in Africa. In East Africa, the Great Rift Valley begins in Ethiopia and runs vertically through desert wastelands for hundreds of miles linking Ethiopia, Kenya, Tanzania, and Botswana. This valley floor is lined with several large soda lakes. These lakes are large basins concentrating huge quantities of mineral salts leached from the volcanic soils by rainwater runoff over millennia. Along with the intense heat and sunlight of the area, these lakes provide the perfect growing conditions for Spirulina.
In Ethiopia, three soda lakes, Lake Aranguadi (Hadho) (approx. 3 km south of Debre Zeit), Lake Chitu (approx. 37 Km west of Shashemene near by Senbete Shala and Lake Shala (approx. 40 km West of Shashemene near by Senbete Shala) at together cover over 3 square miles. All three are rich with spirulina. But Kenya and Chad are the spirulina “bread baskets”. Lake Bogoria (11+ square miles)*, Lake Elementita (7+ square miles), Lake Magadi (29+ square miles), Lake Nakuru (30 square miles), and Lake Rudolf (2,325 square miles), all contain quantities of spirulina
Huge Lake Chad, which is situated both in Chad and Nigeria, contains spirulina in one section of the lake that comprises approximately one-fourth of its surface area, or 1,600 square miles. Based on observed growth rates of 10 grams per square meter per day, Scientists of the Microalgae International Union calculate that Lake Bogoria alone is capable of producing continuously over 290 tons of dry spirulina per day.
On survival rations, 30 grams per person per day, that is enough spirulina to feed over 9 1/2 million people! Surely, enough Spirulina can be harvested, dried and transported from politically stable Kenya alone to feed all the starving people of Africa. In fact, no one ever needs to go hungry again, provided there is the cooperation, funding, and technology to end world hunger.
Transmission Electron Microscope observations show for Spirulina prokaryotic organization, capsule, pluri-stratified cell wall, photosynthetic or thylakoid lamella system, ribosomes and fibrils of DNA region and numerous inclusions. The capsule has fibrillar structure and covers each filament protecting it. The irregular presence of capsule around the filaments in S. platensis is a differentiating morphological characteristic to compare with S. maxima. Trichome width varies from 6 to 12 μm, and is composed of cylindrical cells. The helix diameter varies from 30 to 70 μm; the trichome length is about 500 μm, although in some cases when stirring of culture is deficient the length of filament reaches approximately 1 mm. It is very important to explain that the helical shape of Spirulina in liquid culture is changed to spiral shape in solid media. These changes are due to hydratation or dehydratation of oligopeptides in the peptidoglycan layer.
Spirulina cell wall is formed by four numbered layers, from the inner most outward as: LI, LII, LIII and LIV. All these layers are very weak, except layer LII made up of peptidoglycan, substance that gives the wall its rigidity. The LI layer contains b-1, 2-glucan, a polysaccharide not very digestible by human beings. However, the low concentration (<1%) of this layer, thickness its (12 nm), and the protein and lipopolysaccharide nature of the LII layer are favorite reasons for the easy human digestion of Spirulina.
In this microorganism chlorophyll a, carotenes and phycobilisomes, which contain phycocyanin (blue pigment), are located in the thylakoid system or photosynthetic lamellas. The inter-thylakoid space is limited by the presence of electronically transparent protein gas vesicles, with the cylindrical form that give Spirulina its floating capacity. Ribosomes and fibrils of DNA region are generally of central localization.
Spirulina contains numerous characteristic peripheral inclusions associated to thylakoids. Those are: cyanophycin granules, polyhedral bodies, polyglucan granules, lipid granules, and polyphosphate granules. The cyanophycin granules, or reserve granules, are important due to their chemical nature and a series of pigments. The polyhedral bodies or carboxysomes mainly contain the enzyme ribulose 1, 5-diphosphate carboxylase that allows the fixation of CO2 in photosynthetic organisms and probably carry out a reserve function. The polyglucan granules or glycogen granules or a-granules are glucose polymers, small, circular and widely diffused in the interthylacoidal space. The lipid granules, b-granules or osmophile granules form the reservation deposit, constituted by poly-b-hydroxybutyrate (PHB), found only in prokaryotes. PHB acts as a carbon and energy reserve.
History of spirulina
Spirulina is thought to have been a food source for the Aztecs in 16th century Mexico, as it’s harvesting from Lake Texcoco and sale as cakes is described by one of Cortés’ soldiers. The Aztecs called it Tecuitlatl, which means the stone’s excrement. Spirulina was found in abundance at the lake by French researchers trait within the 1960s, but there is no reference to its use there as a daily food source after the 16th century. The first large-scale Spirulina production plant was established in the early 1970s and drew attention worldwide.
Spirulina is also understood to have an even longer history in Chad, as far back as the 9th century Kanem Empire. It is still in daily use today, dried into cakes called “Dihe” or “Die” which are new to make broths for meals, and in addition sold in markets. The Spirulina is harvested from small lakes and ponds around Lake Chad. Today Spirulina is consumed by millions of people all over the world and they are discovering lots of health benefits apart from its nutritive value.
Since 1970, Spirulina has been analyzed chemically. It has been shown to be an excellent source of proteins, vitamins and minerals.
Spirulina has a high protein concentration (60%-70% of its dry weight). Spirulina is useful in human nutrition, due to the high quality and quantity of its protein. The nutritive value of a protein is related to the quality of amino acids, digestibility coefficient, as well as by its biological value. Spirulina contains essential amino acids; the highest values are leucine (10.9% of total amino acids), valine (7.5%), and isoleucine (6.8%). Denaturation of Spirulina protein is observed when algae are heated above 67 ºC, at neutral aqueous solution. Hydrophobic regions interaction during heating and hydrogen bonds formation during cooling are aggregation and gelation factors of Spirulina protein.
Among food, Spirulina has a relative high provitamin A concentration. An excessive dose of b-carotene may be toxic, but when the b-carotene is ingested from the Spirulina or another vegetable it is usually harmless since the human organism only converts into vitamin A the quantity it needs. Spirulina is a very rich source in vitamin B12, and that is a reason why these Cyanobacteria are of great value for people needing supplements in the treatment of pernicious anemia.
Spirulina contains 4-7% lipids. Spirulina has essential fatty acids: linoleic acid (LA) and g-linolenic acid (GLA). The latter is claimed to have medicinal properties and is required for arachidonic acid and prostaglandin synthesis. GLA lowers low-density lipoprotein, being 170-fold more effective than LA.
Iron in some nutritional complements is not appropriately absorbed. Iron in Spirulina is 60% better absorbed than ferrous sulfate and other complements. Consequently, it could represent an adequate source of iron in anemic pregnant women.
Spirulina platensis contains about 13.6% carbohydrates; some of these are glucose, rhamnose, mannose, xylose and galactose. Spirulina does not have cellulose in its cell wall, a feature that makes it an appropriate and important foodstuff for people with problems of poor intestinal absorption, and geriatric patients. A new high molecular weight polysaccharide, with immunostimulatory activity has been isolated from Spirulina and is called “Immulina”. This highly water-soluble polysaccharide represents between 0.5% and 2.0% (w/w) of the dry microalgae.
Nucleic acids content
One of the main concerns about the consumption of microorganisms is their high content of nucleic acids that may cause disease such as gout. Spirulina contains 2.2%-3.5% of RNA and 0.6 %-1% of DNA, which represents less than 5% of these acids, based on dry weight. These values are smaller than those of other microalgae like Chlorella and Scenedesmus.
Some natural pigments are found in Spirulina. These pigments are responsible for the characteristic colors of certain flamingo species that consume these Cyanobacteria in the African Valley. This knowledge has promoted the use of this microorganism as source of pigmentation for fish, eggs and chicken. Spirulina also increases the yellowness and redness of broiled chicken due to accumulation of zeaxanthin.
Spirulina contains the most remarkable concentration of nutrients known in any food, plant, grain or herb. Spirulina has the highest protein food which is over 60% of all the digestible vegetable protein. Most notably, spirulina is 65 to 71% complete protein, with all essential amino acids in perfect balance. In comparison, beef is only 22% protein. It also has the highest concentration of beta carotene, vitamin B-12, iron and trace minerals and the rare essential fatty acid GLA. These surely make Spirulina an incredible whole food alternative to the isolated vitamin and minerals.
Spirulina is overloaded with unique phytonutrients like phycocyanin, polysaccharides and sulfolipids that not only enhance the immune system, but also reduces the risks of infection, cancer and auto immune diseases. Spirulina is rich in natural carotenoid antioxidants that promote cellular health and lessen the risk of cancer. It also has cleansing chlorophyll which helps detoxify bodies that are always prone to present pollution.
Scientifically explained the most important dictate of our body’s metabolism is to support our immune system. When our immune system is stressed or is suffering, it draws on our body’s metabolic energy. People with immune system imbalance often feel chronic fatigue and low energy.
Both scientific research and the experience of thousands of consumers indicate that Spirulina is an immune regulating food. Small amounts can help balance and stabilize the immune system, freeing up more of our metabolic energy for vitality, healing and assimilation of nutrients. It enhances the body’s cellular communication process and also has the ability to read and repair DNA, like a kind of cellular tune up. This is why individuals taking Spirulina often report they have more energy levels.
Comparison of spirulina nutrients with others
Besides lots of clean air and water, the human body needs a minimum of seven essential nutritional elements in order to survive. These essential elements fall into seven major categories, all of which are abundantly present in Spirulina. These elements include: proteins and amino acids, vitamins, minerals, enzymes, pigments, carbohydrates and lipids (fats).
Next to water, protein is the most abundant compound in your body. Of the approximately 70 trillion cells which make up your body, one-third is constantly aging, wearing out and being replaced by new cells. Dietary protein is essential for this maintenance process. It is estimated that 2.5 million red blood cells, 20,000 white blood cells and five million platelets are sent into your bloodstream each second.
When protein is used by the body for one of these purposes, it is first digested by being broken into separate elements (called amino acids) and then carried to the liver. From there, the amino acids are sent to tissues where new cells are being manufactured or old ones are being repaired. They are absorbed into cells through the cell membranes and recombined into specially manufactured proteins.
Amino acids are your body’s building blocks. Out of the 22 amino acids that you require, only 13 can be manufactured by your body. The remaining 9, the “essential amino acids”, must be derived daily from the foods you eat.
They must also be available to the body simultaneously and in the proper ratio or they cannot be fully utilized. These amino acids must be supplied on a regular basis to provide the sustained energy vital for your growth and health. Otherwise, your body will become protein starved.
The process of amino acid synthesis is complex, dependent on the presence of other nutritional elements from the other 6 categories listed above. To the extent there is an imbalance or deficiency, the 18 amino acids provided by spirulina, in near perfect ratios, become essential. This condition is especially true among the malnourished, undernourished and starving creatures who are presently struggling to survive on the planet.
The cell walls of most vegetables are composed of cellulose. Cellulose is not digestible by humans. Spirulina’s cell walls are mucopolysaccharides (complex sugars) that are easily digestible, freeing considerable energy as a result. Digestibility tests have shown spirulina to be 83 to 95% digestible.
The usable protein in Spirulina therefore, because of its digestibility and amino acid balance, is around 90%, the highest of any protein other than casein (the standard on which all protein assimilation is scientifically evaluated). For comparison, an 8 ounce steak is about 22% protein only 15% of which is usable by the body. So that 8 ounce steak gives only about 1.8 ounces of protein, only .27 ounce (7.6 grams) of which is actually usable protein. Spirulina, however being 70% protein and 90% digestible, provides 5 ounces (140 grams) of usable protein in each 8 ounces.
That is 18 times more protein than steak, with little, if any, waste. In addition, most of spirulina’s proteins are already in the proper form that the body itself creates in the liver so there is little energy lost in digestion. These building blocks of the body are called biliproteins. Spirulina is the most prolific source of biliproteins presently known.
For vegetarians, soybeans in the form of tofu, soy flour, etc., are often cited as a high protein source. At 37% protein and only 25% digestible (usable), an 8 ounce serving of soybeans gives 74 ounces (21 grams) of usable protein. That is three times better than steak, but only 1/7th as good as spirulina.
Whole wheat flour, the prime staple in most starving people’s diets right now, comes in dead last. The highest protein variety of whole wheat flour is only 14% protein, of which only 9% is digestible (usable).
So an 8 ounce serving of whole wheat flour, then, provides only 1/10th of an ounce (2.8 grams) of usable protein. It may fill stomachs, but wheat flour (or any grain) porridge will not fill the protein needs of the starving. The average male needs 43 grams of usable protein per day, the average female 35 grams.
Spirulina gives 50 times more usable protein than whole wheat flour (2.8 x 50 = 140). Or, to say it another way, it takes only 1/6 ounce (4.5 grams) of Spirulina to get the same amount of protein as 8 ounces of whole wheat flour (provided it finds its way into people’s stomachs). Hopefully, the relief agencies are adding some vitamins and minerals to the flour, because wheat is notoriously low in these as well.
Vitamins and minerals
Spirulina gives as much calcium as milk, 15 times more vitamin A than carrots, 3 times the iron of sirloin steak, 2.5 times the vitamin B-12 of calves’ liver, 3.7 times more potassium than rice. Being high in antioxidants such as Vitamin E, and ferrodoxin, spirulina will store safely for years if kept air and water tight.
Hopefully, the whole wheat porridge is not being heated too high. Cooking destroys many amino acids, vitamins and most enzymes. Spirulina is uncooked, raw food with only the water removed.
All food is, at least potentially, a poison until converted into simple structures by enzymes. Metabolism is an enzymatic process from beginning to end. Whatever their value, none of the other essential nutrients are usable by your body without enzymes. Spirulina is both high in enzymes and thermophilic.
That is, it can withstand relatively high temperatures without losing its properties. In fact, Spirulina is so high in enzyme activity that even after being dried (at 160 0F) it will often start growing again if placed in the right medium, temperature and sunlight.
Chlorophyll is an essential pigment. Spirulina is about 1% chlorophyll, which is 2 to 3 times more than most land plants. Green chlorophyll, which carries CO2 in plant respiration, has nearly the same molecular structure as red hemin, the pigment forming hemoglobin in red blood cells.
The only difference is that chlorophyll has magnesium at the center and hemin has iron. When you ingest chlorophyll, the magnesium is removed and used elsewhere by your body while being replaced by iron. Therefore, chlorophyll is essential to the production of red blood cells which carry life-giving oxygen to all your body cells. Chlorophyll does other things as well.
Research indicates that it may slow and strengthen contractions of the heart muscle, help muscles and nerves recover from stress and strain, encourage peristaltic action in the intestines, prevent the growth of harmful bacteria, to name a few.
Bile pigments aid the rapid breakdown and metabolism of starches, proteins, and fats. A bile pigment called phycocyanin makes up 7 to 18% of spirulina’s weight. There is no other food, animal or vegetable, which contains even a quarter of the bile pigments found in spirulina.
Doubling every 3 days under the right conditions, Spirulina is the fastest growing human food. This “Spirulina Growth Factor” (SGF) is found to enhance enzyme activity and trigger faster cell growth, repair and replication where needed in tissues and organs, thus helping the body to rebuild and rejuvenate itself.
Spirulina has 16.5% carbohydrates, of which 9% is a rare sugar known as rhamnose. Rhamnose is more biologically active than other sugars because it combines more readily with other nutrients. Unlike sucrose, it does not upset the blood sugar balance or overwork the pancreas.
Like proteins, carbohydrates go through a complex breakdown and recombination process in your body. One of the products of this process is glycogen, a complex sugar that your body stores in the liver until energy is needed.
Spirulina is the only known vegetable that contains glycogen (0.5%). So, like its biliproteins, spirulina’s glycogen is ready made for direct assimilation and use. Spirulina also contains important carbohydrates known as glycosides and bioflavonoids which affect many cellular processes too numerous to mention here. Although relatively low in calories (381 calories per 100 grams), spirulina is high in energy from these carbohydrates.
Essential fatty acids (EFA’s) are vitamin-like substances that are essential to life. They cannot be produced by your body and are therefore “essential” in your diet. EFA’s include linoleic, linolenic and arachidonic acids.
EFA’s help to reduce total cholesterol and triglyceride levels (associated with arteriosclerosis and heart disease). They also help to protect the body against sodium-induced high blood pressure, normalize biochemical factors associated with diabetes, enhance sexual effectiveness, fertility, and prevent dry scaly skin and fragility of cells.
Cell membranes are largely composed of lipids. When present with Vitamins E and A (which prevent dangerous lipid peroxidation or rancidity) EFA’s protect the cell membranes against anti-oxidant and free radical attacks. Such attacks can alter the absorption of nutrients through the cell membranes. Since membrane damage may alter antigens (substances that induce the formation of germ-killing antibodies) this could cause the immune system to fail. Research with a special fatty acid called gamma linolenic acid (GLA) has reportedly shown it to be effective in strengthening the body’s immune system.
Spirulina is relatively high in lipids, containing 7% by volume. Over 2 1/2% of Spirulina consists of the EFA’s linoleic and linolenic. With 1.2% to 2% GLA, Spirulina is also nature’s highest available source of GLA. Mother’s milk is the highest known source of GLA (provided it is in the mother’s diet) and is one of nature’s ways of protecting babies from disease.
Thus, EFA’s are essential in the diets of everyone, and certainly in those recovering from starvation, since EFA’s help the body resist the diseases to which the malnourished are exposed in their weakened state.
Health benefits of spirulina
Some of the health benefits of Spirulina are
• Encouraging weight loss
• Counteracting toxins in the body
• Helping purify the liver
• Increasing mental alertness
• Lowering blood cholesterol and excess triglycerides
• Helping fight viral infections
• Treating radiation sickness
• Enhancing ability to generate new blood cells
• Improving blood sugar problems
• Strengthening the nervous system
• Strengthening the immune system
• Removing toxic metals such as lead and mercury from the body
• Improving healing of wounds
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to treat, prevent, cure or diagnose any disease. The information provided is for educational purposes only and does not constitute medical advice. Always seek the advice of your physician or qualified healthcare provider with any questions or concerns about your health.
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