Chlorella algae

What is chlorella?

Chlorella is a single-celled green freshwater algae (1). There are over 30 different species, of which two types - Chlorella vulgaris and Chlorella pyrenoidosa - are most commonly used in supplements (2). Chlorella contains large amounts of protein and chlorophyll compared to other plants, as well as large amounts of minerals such as iron and magnesium and vitamins such as folate, vitamin B6 and vitamin B12. The protein contained in chlorella contains all the essential amino acids that humans need for growth and health. Since chlorella has a very hard cell wall that humans cannot digest, chlorella must be used as a supplement if you want to benefit from the advantages of this algae (3). In addition to its use as a dietary supplement, chlorella is also used in the production of biodiesel (4).

Where does chlorella come from

Chlorella is a popular food worldwide and is particularly popular in Japan, Taiwan and Korea. Chlorella can be grown in many different climates and regions.

Chlorella is very nutritious

The impressive nutrient profile has led to chlorella being labeled a superfood by many. Although the exact nutrient content depends on the growing conditions, the species of chlorella used and the processing of the supplement, chlorella contains a whole range of beneficial nutrients.

These include:

Protein: Chlorella consists of 50 to 60% protein. This is a complete protein source, which means that chlorella contains all 9 essential amino acids (3, 5).
Vitamin B12: Some chlorella species also contain vitamin B12, but more research is needed on this (6).
Iron and vitamin C: Chlorella can be a good source of iron. Depending on the supplement, it can provide 6 to 4% of the daily iron requirement. Chlorella is also an excellent source of vitamin C, and the vitamin C it contains helps with the absorption of iron (1, 3, 7).
Other antioxidants: Chlorella provides a wide range of antioxidants (1, 3).
Other vitamins and minerals: Chlorella contains small amounts of magnesium, zinc, copper, potassium, calcium, folic acid and other B vitamins (1, 3, 8).
Omega-3 fatty acids: just like other algae, chlorella also contains omega-3 fatty acids. 3 grams of chlorella provides 100 mg of omega-3 fatty acids (8).
Fiber: in larger quantities, chlorella can be a good source of fiber. However, most supplements provide less than 1 gram of fiber per serving (1, 8).

Benefits of chlorella

Chlorella may have a number of health benefits, which we will look at in more detail in the following sections along with the scientific evidence.

Chlorella binds heavy metals and supports detoxification

Chlorella has caused quite a stir with its ability to support "detoxification" of the body. Research conducted on animals suggests that it may help remove heavy metals and other harmful compounds from the body (9, 10, 11). Heavy metals include some elements such as iron and copper, which are essential in small amounts but, like other heavy metals such as cadmium and lead, can be toxic in larger quantities. Although it is rare for dangerous levels of heavy metals to accumulate in the body, some people are exposed to higher levels through pollution or certain occupations (12). In animals, chlorella has been shown to attenuate the toxic effects of heavy metals in the liver, brain and kidneys (13). In addition, chlorella has been shown to reduce the levels of other harmful chemicals that can be found in food. One of these toxic chemicals is dioxin - a hormone disruptor that can be found in animals in the food chain (14, 15). Based on the scientific evidence, chlorella appears to be able to help increase the body's natural ability to eliminate toxins.

Summary: Chlorella may help detoxify the body by binding heavy metals and other toxins.

Chlorella could improve the function of the immune system

Your immune system helps keep you healthy by fighting infections. It is a complex system made up of multiple mechanisms and cells that become active when an invader enters the body. Studies in animals and humans have shown that chlorella can enhance the immune system's response, although evidence is limited. In one small study, men produced more antibodies after taking chlorella than after taking a placebo. Antibodies help the body fight pathogens, which means that these study results are quite promising (16). In another small, eight-week study, healthy adults taking chlorella showed markers of increased immune system activity (17), but the study results are mixed, with some studies showing little or no effect. One study, for example, found that chlorella supplements improved immune function in study participants aged 50 to 55, but not in subjects over 55 (18).

It is therefore possible that chlorella has an effect on improving immune function in some populations and age groups, but not in all. Further, larger-scale studies are needed to find this out.

Summary: Chlorella may improve immune function by increasing the activity of different parts of the immune system.

Chlorella could help improve cholesterol levels

Several studies have suggested that chlorella supplements may help lower cholesterol levels (5, 19, 20). Studies have shown that taking 5 to 10 grams of chlorella per day can lower total cholesterol levels, LDL cholesterol levels and triglyceride levels in people with high blood pressure and/or slightly elevated cholesterol levels (5, 19).

Chlorella's content of the following compounds may help improve blood lipid levels.

Niacin: A B vitamin known to lower cholesterol levels (21).
Dietary fiber: A cholesterol-lowering ingredient (1, 22).
Carotenoids: These have been shown to naturally lower cholesterol levels (19, 23, 24).
Antioxidants: Help reduce the oxidation of LDL cholesterol, which is known to contribute to heart disease (25).
Summary: The nutrients such as niacin, fiber, carotenoids and antioxidants found in chlorella may help lower cholesterol levels.

Chlorella acts as an antioxidant

Chlorella contains several compounds that are considered antioxidants. These include vitamin C, beta-carotene, lycopene and lutein (26). These antioxidants can help fight many chronic diseases (26). Some of these antioxidants appear to reduce the production of advanced glycation end products (AGEs), which are the driving factor in many complications of diabetes (1, 27). In animal and laboratory studies, chlorella has been shown to alter the way genes age (1, 28). A human study also showed that chlorella supplements can increase antioxidant levels in chronic smokers - a population at increased risk of oxidative damage (29, 30).

However, while many of these studies are promising, they are still preliminary in nature.

Summary: The antioxidant content of chlorella may offer some protection against chronic disease, but further human studies are needed to confirm this.

Chlorella may help keep blood pressure under control

Chlorella supplements may help promote heart and kidney health, which is essential for normal blood pressure. In one study, subjects with slightly elevated blood pressure took four grams of chlorella per day for 12 weeks. At the end of the study, these people had lower blood pressure than those who had taken a placebo (31). Another small study conducted with healthy men showed that taking chlorella supplements was associated with less stiff arteries - a factor that affects blood pressure (32). One theory to explain this is that some of the nutrients found in chlorella, including arginine, potassium, calcium and omega-3 fatty acids, may help prevent hardening of the arteries (32, 33).

Summary: Some studies conducted with chlorella indicate a blood pressure-lowering effect. Many of these nutrients have been shown to prevent hardening of the arteries.

Chlorella could improve blood sugar levels

Some studies show that chlorella may help to lower blood sugar levels (1). One study found that taking chlorella for 12 weeks could lower fasting blood glucose levels in both healthy individuals and those at high risk of lifestyle-related diseases (20). Other studies have shown that chlorella supplementation can improve glycemic control and insulin sensitivity in subjects with non-alcoholic fatty liver disease (34, 35, 36).There is not enough research to say that chlorella should be taken for glycemic control, but it may be helpful when combined with other therapies.

Summary: Taking chlorella supplements could help lower blood sugar levels and improve insulin sensitivity.

Chlorella could help with respiratory diseases

The treatment of respiratory diseases such as asthma and COPD often requires control of inflammation (37, 38). Chlorella contains several compounds that can help reduce inflammation. These include many antioxidants (1, 39). One study found that chlorella supplements improved antioxidant status in COPD patients, but this was not reflected in an improvement in breathing ability (40). Further studies are needed to determine the true effects of chlorella on respiratory conditions, but chlorella may help with inflammation.

Summary: The antioxidants found in chlorella have anti-inflammatory effects that may be able to alleviate asthma and other respiratory conditions.

Chlorella could increase aerobic endurance

Only one study has investigated the effects of chlorella on aerobic endurance, but it has shown a positive effect.

Scientists administered six grams of chlorella or a placebo per day to a group of young adults for four weeks. At the end of the study, the chlorella group showed a significantly improved ability to saturate their lungs with oxygen, which is a measure of endurance. The placebo group experienced no change in endurance (41). This effect may be due to chlorella's branched-chain amino acid content. Branched-chain amino acids are a group of three amino acids that have been shown in several studies to improve aerobic endurance (42, 43).

Summary: Chlorella may enhance aerobic performance, although the scientific support for this benefit is limited.

Other potential benefits of chlorella

There are numerous other proposed potential benefits, but there is limited research to support these claims.

Here are some of them

Promoting eye health: Chlorella contains lutein and zeaxanthin - two carotenoids that may protect the eyes and reduce the risk of macular degeneration (44, 45, 46).
Supporting liver health: Chlorella supplements have been shown to improve markers of liver health in people with liver disease. However, it is not known whether this is also a benefit for healthy people (34, 35, 36, 47).
Improved digestion: Many sources claim that chlorella eases digestion and can reduce a bloated feeling. However, there are no studies to confirm this.
Relief of PMS symptoms: Anecdotal reports suggest that chlorella can relieve PMS symptoms. This might be far-fetched, but chlorella contains calcium and B vitamins, which have been shown to reduce PMS symptoms /48, 49).
A reduction in the transfer of dioxins from the mother to the fetus via the placenta or when breastfeeding babies via breast milk (54).
An increase in bone density in postmenopausal women (55).
A reduced risk of pregnancy-related anemia, proteinuria and edema (56).
Summary: It is claimed that chlorella can increase energy levels, improve liver health, aid digestion and reduce PMS symptoms. However, there is a lack of scientific studies that directly support this.

Possible concerns

Chlorella is generally considered safe and harmless (1). However, there are a few things to keep in mind when considering supplementing with chlorella:

Possible side effects: Some people report nausea and abdominal pain (51).
Inconsistent products: The nutrient content of chlorella supplements can vary depending on the algae species, growing conditions and processing (52, 53).
Effects on immune function: Since chlorella affects the immune system, it may not be suitable for people with reduced immune function or people taking medications that affect the immune system.

In addition, it should be remembered that supplements can interact with some medications. Even though chlorella is generally considered safe, it may not be suitable for everyone.

Recommended intake

The available scientific literature does not provide specific dosage recommendations. This is because there is insufficient data to determine the amount needed for therapeutic effects (1). Some studies have observed positive effects at doses in the range of 1.2 grams of chlorella per day, while others have used doses in the range of 5 to 10 grams (5, 19, 34, 35, 36). For most supplements, dosages in the range of 2 to 3 grams are recommended, which seems reasonable given the available research. However, it is important to find a high quality supplement

Chlorella supplements

Chlorella is available either on its own as a powder or more commonly in combination with other popular superfoods such as spirulina, wheatgrass or barley grass. Such supplements are typically sold as "greenfood" or "greens" supplements.

Combination with other supplements

As mentioned above, chlorella is most commonly combined with spirulina, wheatgrass and/or barley grass.

Conclusion

Chlorella is an algae that is highly nutritious and a good source of several vitamins, minerals and antioxidants. Scientific research shows that chlorella may help eliminate toxins from the body, improve cholesterol levels and lower blood sugar levels, to name a few. According to current evidence, taking chlorella supplements appears to be safe and could support health.

References

Further sources

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Lee SH, et al. Six-week supplementation with Chlorella has favorable impact on antioxidant status in Korean male smokers. Nutrition. 2010;26(2):175-183.
Borowitzka MA, et al. Vitamins and fine chemicals from micro-algae. L.J. Borowitzka (Ed.), Micro-algal biotechnology, Cambridge University Press, New York (1988), p. 153.
Schubert LE. The use of spirulina and chlorella as food resource for animals and humans. In: Round FE, Chapman DJ, editors. Progressing physiological research. Bristol, U.K.: Biopress Ltd; 1988, p. 237.
Shibata S, et al. Antioxidant and anticataract effect of Chlorella on rats with streptozotocin-induced diabetes. J Nutr Sci Vitaminol. 2003;49:334-339.
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Konishi F, et al. Protective effect of an acidic glycoprotein obtained from culture of chlorella vulgaris against myelosuppression by 5-fluorouracil. Cancer Immunol Immunother. 1996;42:268-274
Singh A, et al. Perinatal influence of Chlorella vulgaris on hepatic drug metabolizing enzyme and lipids. Anticancer Res. 1998;18:1509-1514.
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Tanaka K, et al. Oral administration of a unicellular green algae, Chlorella vulgaris, prevents stress-induced ulcer. Plant Med. 1997;63:465-466.
Hasegawa T, et al. Toll-like receptor 2 is at least partly involved in the antitumor activity of glycoprotein from Chlorella vulgaris. Int Immunopharmacol. 2002;2:579-589.
Sano T & Tanaka Y. Effects of dried powdered Chlorella vulgaris on experimental atherosclerosis and alimentary hypercholesterolemia in cholesterol-fed rabbit. Artery.1987;14:76–84.
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Otsuki T, et al. Salivary Secretory Immunoglobulin a secretion increases after 4-weeks ingestion of chlorelladerived multicomponent supplement in humans: a randomized cross over study. Nutrition Journal. 2011;10:91.
Halperin SA, et al. Safety and immunoenhancing effect of a Chlorella derived dietary supplement in healthy adults undergoing influenza vaccination: randomized, double-blind, placebo-controlled trial. CMAJ. 2003;169(2):111-117.