chlorella benefits
chlorella supplement

What is Chlorella ?

Chlorella (Chlorella vulgaris) is a microscopic green algae, not much larger than a red blood cell. The name of this single-celled water plant comes from the Greek chloros = green or yellow-green and –ella = small. The microalgae is spherical in shape and appears worldwide. Chlorella has been safely consumed as a food ingredient in Mexico and Central Africa for the past four centuries and currently is used as dietary supplements and a novel food ingredient, especially among Asians, including Asian-Americans 1), 2). No member of the Genus Chlorella is known to be toxic.

Chlorella, is a class of cyanobacteria, is free-floating filamentous microalgae that is capable of photosynthesis 3). Chlorella has long been a popular functional food worldwide because it is rich in essential nutrients, including high-quality protein, vitamins, minerals, and essential amino acids. Chlorella is especially high in protein (approximately 60%) and its amino acid quantity and quality are similar to those of a chicken egg (regarded as a perfect protein) except for methionine and tyrosine 4). Numerous studies demonstrated physiological benefits of Chlorella vulgaris, such as hypoglycemic and hypocholestrolemic effects, immune activation, antioxidant activity, anticarcinogenic activity, antitoxic effects against meta-induced toxicity, dioxin-induced damages and infection 5), 6)), 7)), 8), 9), 10), 11), 12). In United States chlorella can be found added to fruit juice smoothie, granola bars, cereal bars, protein bars, energy drinks, fruit juices, soy milk, meal replacements, chlorella supplement, medical foods and sport beverages. The U.S. Food and Drug Administration (FDA) classify chlorella as GRAS (Generally Recognized As Safe) for its intended use in food  13). There are no indications of significant adverse effects related to Chlorella vulgaris in the publicly available literature. In the United States, the safety of Chlorella vulgaris has been recognized under the Dietary Supplement Health and Education Act of 1994. However, chlorella vulgaris is not intended for use in meat- or poultry-containing products or as a coloring agent 14).

Table 1. Chlorella vulgaris – powder (typical average composition)

ApproximatesPer 100 Gram Chlorella vulgaris product
Typical Composition
Moisture4 g
Lipids9 g
Dietary Fiber18 g
Carbohydrates9 g
Sugars1 g
Protein52 g
Ash7 g
Pigments3 g
Total chlorophyll2.4 g
Total carotenoids170 mg
Vitamin K33 µg
Vitamin B61 mg
Vitamin B9 (folic acid)610 µg
Vitamin B12100 µg
Vitamin C19 mg
Vitamin E6 mg
Calcium316 mg
Potassium1496 mg
Magnesium318 mg
Iron112 mg
Zinc4 mg
Amino Acid Profile (* essential amino acids)% amino acid / total amino acids
aspartic acid9.5%
glutamic acid11.9%
total saturated fatty acids2.9 g
total mono-unsaturated fatty acids1.5 g
total polyunsaturated fatty acids4.8 g
Trans fat89 mg
Fatty acids profile% fatty acid / total fatty acids
C16:0 palmitic acid25.2%
C18:0 stearic acid2.6%
C18:1 oleic acid5.2%
C18:2 linoleic acid19.3%
C18:3 α-linolenic acid30.7%
[Source: Roquette Klötze GmbH & Co. KG. Chlorella 15)]
Note: The topic of the bioavailability of vitamin B12 from algae is a point of controversy. And in fact there are indeed major differences between algae with regard to the presence of various cobalamins and their bioavailability. Roquette Klötze GmbH’s Chlorella contains 100 μg of total vitamin B12 per 100 g of product, i.e. the recommended daily dose of 3 g of Chlorella represents 120 % of the daily requirement 16).

Chlorella is one of the most studied microalgae, is commercially cultivated by more than 70 companies in the world 17). The annual production of Chlorella biomass exceeds 2,000 tonnes 18), mostly used for dietary supplements and nutraceuticals, with a minor share destined to the cosmetic market and aquaculture 19). Chlorella is commercially produced under photoautotrophic conditions, mainly in open ponds (both raceway and circular) 20), 21), or heterotrophically in fermenters 22). The largest closed system used for autotrophic production at commercial scale is the 700 m3 tubular photobioreactor operated by Roquette Klötze GmbH & Co. KG (Klötze, Germany), which produces annually about 100 tonnes of high quality Chlorella biomass for the health food market 23).

General properties of Chlorella vulgaris

Chlorella is a free-flowing, dark blue-green powder with a mild seaweed smell, produced by spray drying the biomass of the cyanobacterium, Chlorella vulgaris
24). It is not readily soluble in water or solvents, but it forms a suspension when mixed in water. Chlorella species are eukaryotic, unicellular, non-motile freshwater green algae that belong to the Division Chlorophyta 25). Chlorella cells have hemicellulosic cell walls and are spherical with a diameter ranging from 2 to 10 µm 26).

Chlorella vulgaris Cell Walls

The question frequently arises of whether the Chlorella cell walls have to be broken up in some way (in a ball mill, with ultrasound, etc.) in order to improve their digestibility or other properties.

The cell walls of our Chlorella are not broken up and indeed don’t have to be 27).

Various investigations into this have shown: The digestibility of Chlorella is not significantly increased by breaking up its cell walls 28).

Factors such as the drying process or the species (strain) of Chlorella used, have a greater impact. This is summarized as follows in a publication by T. Kanno (2005), stating that “The original characteristics and the physiological effects of Chlorella are not changed by breaking up the cell wall” and “It is more to be feared that the process of breaking up the cell wall may degrade proteins, destroy vitamins, and fatty acids, thereby resulting in oxidation effects.”

Benefits of Chlorella

Chlorella is one of the few microalgae (together Arthrospira platensis- also known as Spirulina) largely employed for human consumption. It has a high protein content with a balanced amino acid composition 29), 30), besides a good content of vitamins, minerals, pigments 31) and short-chain polyunsaturated fatty acids, including oleic and linoleic acids 32), 33). Some strains are also a good source of lutein 34). Chlorella is recognized as a safe food ingredient worldwide 35), mainly due to its long history of human consumption as a food supplement and nutraceutical 36), 37). In vivo studies on its potential as food and protein source have been carried out mainly in the past 38), 39), when legislation concerning trials on people was less restrictive. More recently, Chlorella biomass has been proposed as a food ingredient: as colouring agent for traditional butter cookies 40), as additive for fermented milk and yoghurt to enhance the viability of bacterial probiotics 41), 42) and incorporated in pasta products to increase their nutritional quality 43). A Chlorella protein hydrolysate has also been tested as a food additive 44).


Chlorella supplementation in adults with chronic hepatitis C virus infection

Complementary and alternative medicines to treat chronic liver diseases, including chronic hepatitis C virus (HCV) infection, are becoming increasingly popular in North America. Infection with hepatitis C virus is global in nature, infecting approximately 160 million persons worldwide or roughly 2% of the world population, with some countries documenting a rate of 15% or more 45), 46). After an initial hepatitis C virus infection, close to 70% of cases develop chronic infection that may progress to liver cirrhosis and hepatocellular carcinoma if left untreated 47).

In animals, Chlorella has been reported to improve host resistance to viral infection and tumors 48), 49), 50). In humans, Chlorella supplementation has been shown to enhance the antibody titer after influenza immunization 51), and to improve the outcome in several chronic diseases. Chlorella supplementation has been also associated with an improvement in liver function in animal models 52), 53). Due to the documented benefits of Chlorella treatments in liver diseases in animals and in chronic diseases in humans, a study was conducted on the effects of Chlorella in 18 patients with chronic hepatitis C virus genotype 1 infection 54). The plasma hepatitis C virus RNA levels, hematological and chemistry results, including liver enzyme levels, and the quality of life and psychological well-being were assessed in this cohort following dietary supplementations with Chlorella-derived products 55).

RESULTS: A majority 84.61% of the patients had a significant decrease in their ALT levels from week 0 to week 12 56). Evaluation of side effects showed that Chlorella was well tolerated. Quality of life assessment showed that 76.9 of the participants reported an improvement in their energy levels and 46.1% reported an improvement in their perception of general health. Although 69.23% also showed a decrease in their AST levels, this was not statistically significant 57). Most patients that exhibited an improvement in their ALT and AST levels also showed a tendency toward a decreased hepatitis C virus viral load. The hepatitis C virus RNA levels showed a decrease in 69.23% of the patients, which along with changes in AST/ALT ratios from week 0 to week 12, these results were not statistically significant 58).

CONCLUSION: Chlorella supplementation was well tolerated in patients with chronic hepatitis C virus and associated with a significant decrease in ALT liver enzyme levels 59).

Chlorella Supplement

Chlorella vulgaris & Chlorella pyrenoidosa ‘species’ are currently the types of Chlorella most frequently found in shops 60). However, it has been known since 1992 (E. Kessler and V.A.R. Huss) that there is no separate species “Chlorella pyrenoidosa”. This has been confirmed in various subsequent studies. This is in fact more due to an outdated concept of a “species” that was used for various different species and strains of algae groups. The underlying species when documents mention “C. pyrenoidosa” will for example be Chlorella vulgaris, Chlorella sorokiniana and Chlorella fusca 61).

The intended maximum safe dosage of chlorella vulgaris is 15.5 g/day (241 mg/kg of body weight/day) for males and 7.5 g/d (139 mg/kg of body weight/day) for females 62). And
these levels are much lower than the safe use levels of 20-100 g/day that have been reported in human clinical trials 63).

Chlorella supplement has been taken as tablets, capsules, extract liquid or a food additive; claims for health benefits have included improvement of immune function 64) and improvement in control of hypertension, fibromyalgia and ulcerative colitis 65).

In a small study involving 55 participants with fibromyalgia, 33 with hypertension, and 9 with ulcerative colitis 66). The participants consumed 10 g of pure chlorella in tablet form and 100 mL of a liquid containing an extract of chlorella each day for 2 or 3 months. According to the researchers, daily dietary supplementation with chlorella may reduce high blood pressure, lower serum cholesterol levels, accelerate wound healing, and enhance immune functions 67). However due to the small size and poorly designed nature of the study, larger, more comprehensive randomised clinical trials of chlorella for the treatment of fibromyalgia, hypertension, and ulcerative colitis are warranted before we could validate the conclusion of that study.

In another small study to study the beneficial immuno-stimulatory effect of short-term Chlorella supplementation involving 23 subjects who were given 5g of Chlorella vulgaris tablets per day 68). The subjects were instructed to consume 5 g/d of Chlorella (12 pills/d) or placebo (12 pills/d) by taking 4 pills after each main meal. All participants were encouraged to maintain their usual lifestyle and dietary habits. This study shows that 8-week supplementation of Chlorella tablets may give a beneficial immuno-stimulatory effect to normal (uninfected) people by enhancing the NK (natural killer) cell activity and producing INF-γ and IL-12 as well as IL-1β, the Th-1 cell-induced cytokines 69).

Chlorella Side Effects

Findings from acute, subacute, subchronic, and reproductive toxicity studies of Chlorella vulgaris 70), 71), 72), 73). The consumption of Chlorella vulgaris at a dose up to 10% in the diet (equivalent to 10,000 mg/kg body weight/day), the maximum level tested, had no adverse effects in rats 74). In mice, 1% in the diet, which is equivalent to 1,500 mg/kg body weight/day, the maximum level tested, did not show any adverse effects. The NOAEL (no-observed-adverse-effect-level) was determined to be 10% in the diet or 10,000 mg/kg BW/d. In addition, no member of the Genus Chlorella is known to be toxic.

Human clinical studies reported no adverse effects related to the consumption of Chlorella. The consumption of Chlorella vulgaris up to 20 g/d did not show adverse effects 75). Also, other species of Chlorella was well-tolerated at concentrations up to 100 g/day 76).

Even though Chlorella has been reported to be generally safe, Chlorella can cause side effects in some individuals. Some of the symptoms include swelling of the face or tongue sensitivity to sunlight, digestive upset, acne, fatigue, lethargy, headaches, vertigo, and shaking.

Pregnant and nursing women should talk to their individual doctors and midwives to evaluate if these supplements would be safe or beneficial for them.

Due to its high Vitamin K content, it will increase clotting, those that have been prescribed Coumadin or Warfarin should consult with their physician prior to using chlorella. Lastly some individuals can have allergies, allergy to iodine, hypersensitivity and intolerance to microalgae.

Chlorella vs Spirulina

While most Americans may have not heard of chlorella, many people have been taking spirulina for years. They are both waterborne organisms, but at the cellular level, they are quite different. Both spirulina and chlorella have a concentrated balance of nutrients shown to help cleanse and detoxify the body, and a high concentration of protein that supports energy and clarity.

Table 2. Spirulina (Seaweed Dried)

[Source: United States Department of Agriculture, Agriculture Research Service. USDA Food Composition Databases. 77)]

Table 3. Spirulina (Seaweed Raw)

[Source: United States Department of Agriculture, Agriculture Research Service. USDA Food Composition Databases. 78)]

Difference Between Chlorella and Spirulina

Though they look, smell and even taste similar, there are few key differences:

  • Structure: Both are types of algae, but Chlorella is a true single-cell algae with a nucleus, while Spirulina is a multi-celled plant with no distinctive nucleus. For this reason, spirulina is much larger than chlorella.
  • Color: Spirulina is a cyanobacteria, a blue-green type of algae, while Chlorella is a green algae.
  • Amount of Nucleic Acids: Both are a good source of nucleic acids, though Chlorella has almost twice as much as Spirulina. Nucleic acids are important factors for DNA and RNA in the body.
  • Digestibility: Spirulina can be consumed easily after harvest while Chlorella has to go through a process to break its cell walls before the body can use it.
  • Chlorophyll Content: Chlorella is higher in Chlorophyll, with almost double the amount.
  • Iron, Protein and GLA: Spirulina is higher in Iron, protein and beneficial Gamma-Linolenic Acid (GLA).
  • Vitamin B12: Chlorella has vitamin B12 whereas Spirulina has none.
  • Folate (folic acid or vitamin B9): Chlorella has 610 µg whereas Spirulina only 94 µg per 100 gram dried powder.
  • Heavy Metals: Chlorella has unique properties in its cell walls that make it bind to heavy metals and other contaminants (spirulina does not have this same benefit).

References   [ + ]

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