Chlorella

Last Updated: March 19, 2024

Chlorella is a freshwater green alga commonly used as a plant-based source of vitamin B12 for vegans and vegetarians. It’s a rich source of micronutrients and may have benefits for cardiometabolic health, immune function, pregnancy, and exercise performance.

Chlorella is most often used for

What is chlorella?

Chlorella is a green microalga that is primarily composed of protein (up to 60% of its dry weight), including all of the essential and nonessential amino acids, with the most abundant of these being glutamate, leucine, aspartate, and lysine. Chlorella also contains fatty acids — mostly alpha-linolenic acid and linoleic acid — and carbohydrates, most of which are polysaccharides (dietary fibers), including alpha-glucans and beta-glucans.[reference|url=https://pubmed.ncbi.nlm.nih.gov/32825362|title=Potential of as a Dietary Supplement to Promote Human Health.|published=2020-Aug-20|authors=Bito T, Okumura E, Fujishima M, Watanabe F|journal=Nutrients|]

Chlorella is also a rich source of micronutrients, including the minerals sodium, potassium, iron, calcium, magnesium, and zinc; vitamins A, C, E, K1 and the B vitamins (notably vitamin B12); and carotenoids, including astaxanthin, zeaxanthin, beta-carotene, and lutein. Because chlorella is a rich source of vitamin B12, it’s often consumed as a plant-based source of this nutrient by vegans and vegetarians.

What are chlorella’s main benefits?

Although the evidence in humans is somewhat limited, chlorella appears to reduce blood pressure[reference|url=https://pubmed.ncbi.nlm.nih.gov/19811362|title=Anti-hypertensive effect of gamma-aminobutyric acid (GABA)-rich Chlorella on high-normal blood pressure and borderline hypertension in placebo-controlled double blind study|published=2009 Jun|authors=Shimada M, Hasegawa T, Nishimura C, Kan H, Kanno T, Nakamura T, Matsubayashi T|journal=Clin Exp Hypertens|] and enhance immune system function.[reference|url=https://pubmed.ncbi.nlm.nih.gov/21906314|title=Salivary secretory immunoglobulin A secretion increases after 4-weeks ingestion of chlorella-derived multicomponent supplement in humans: a randomized cross over study|published=2011 Sep 9|authors=Otsuki T, Shimizu K, Iemitsu M, Kono I|journal=Nutr J|] For pregnant women, chlorella supplementation is well-tolerated, may reduce the risk of pregnancy-associated anemia, is associated with less leg edema, and increases levels of immunoglobulin A in breast milk.[reference|url=https://pubmed.ncbi.nlm.nih.gov/20013055|title=Chlorella pyrenoidosa supplementation reduces the risk of anemia, proteinuria and edema in pregnant women|published=2010 Mar|authors=Shiro Nakano, Hideo Takekoshi, Masuo Nakano|journal=Plant Foods Hum Nutr|][reference|url=https://pubmed.ncbi.nlm.nih.gov/19699777|title=Preventive effects of Chlorella on cognitive decline in age-dependent dementia model mice.|published=2009-Oct-30|authors=Nakashima Y, Ohsawa I, Konishi F, Hasegawa T, Kumamoto S, Suzuki Y, Ohta S|journal=Neurosci Lett|]

Chlorella has synergistic effects with exercise on body composition and metabolic health.[reference|url=https://pubmed.ncbi.nlm.nih.gov/34178863|title=in combination with high intensity interval training in overweight and obese women: a randomized double-blind clinical trial.|published=2021-Jun|authors=Sanayei M, Izadi A, Hajizadeh-Sharafabad F, Amirsasan R, Kaviani M, Barzegar A|journal=J Diabetes Metab Disord|][reference|url=https://pubmed.ncbi.nlm.nih.gov/34433510|title=High-intensity interval training with or without chlorella vulgaris supplementation in obese and overweight women: effects on mitochondrial biogenesis, performance and body composition.|published=2022-Jul-28|authors=Sanayei M, Hajizadeh-Sharafabad F, Amirsasan R, Barzegar A|journal=Br J Nutr|] It also may be ergogenic, improving maximal and submaximal exercise performance in healthy adults, adults with overweight/obesity, and trained athletes.[reference|url=https://pubmed.ncbi.nlm.nih.gov/25320462|title=Chlorella-derived multicomponent supplementation increases aerobic endurance capacity in young individuals.|published=2014-Sep|authors=Umemoto S, Otsuki T|journal=J Clin Biochem Nutr|][reference|url=https://pubmed.ncbi.nlm.nih.gov/28955131|title=Effect of -derived multicomponent supplementation on maximal oxygen uptake and serum vitamin B concentration in young men.|published=2017-Sep|authors=Zempo-Miyaki A, Maeda S, Otsuki T|journal=J Clin Biochem Nutr|][reference|url=https://pubmed.ncbi.nlm.nih.gov/36905653|title=The Efficacy of Chlorella Supplementation on Multiple Indices of Cycling Performance.|published=2024|authors=Gurney T, Brouner J, Spendiff O|journal=J Diet Suppl|]

What are chlorella’s main drawbacks?

Because chlorella contains a cellulose cell wall (unlike spirulina), it must undergo mechanical processing to break down these cell walls before human consumption to avoid gastrointestinal side effects like nausea, vomiting, and stomach pain.[reference|url=https://pubmed.ncbi.nlm.nih.gov/37432326|title=Bioactivity of Macronutrients from in Physical Exercise.|published=2023-Apr-30|authors=Lorenzo K, Santocildes G, Torrella JR, Magalhães J, Pagès T, Viscor G, Torres JL, Ramos-Romero S|journal=Nutrients|] Furthermore, some studies have confirmed that chlorella is an allergen, so some individuals (notably children) may be sensitive to it or want to avoid its consumption.[reference|url=https://pubmed.ncbi.nlm.nih.gov/7636063|title=Allergy to green algae (Chlorella) among children.|published=1995-Aug|authors=Tiberg E, Dreborg S, Björkstén B|journal=J Allergy Clin Immunol|]

How does chlorella work?

Supplementing with chlorella reduces oxidative stress and increases the activity of enzymatic and non-enzymatic antioxidants in rats[reference|url=https://pubmed.ncbi.nlm.nih.gov/17457522|title=Antioxidant effect of the marine algae Chlorella vulgaris against naphthalene-induced oxidative stress in the albino rats.|published=2007-Sep|authors=Vijayavel K, Anbuselvam C, Balasubramanian MP|journal=Mol Cell Biochem|] and increases antioxidant activity (by increasing levels of catalase and superoxide dismutase) in male smokers.[reference|url=https://pubmed.ncbi.nlm.nih.gov/19660910|title=Six-week supplementation with Chlorella has favorable impact on antioxidant status in Korean male smokers|published=2010 Feb|authors=Lee SH, Kang HJ, Lee HJ, Kang MH, Park YK|journal=Nutrition|] In humans, chlorella has notable antilipidemic, antihypertensive, and antihyperglycemic effects — it reduces total and LDL cholesterol, systolic and diastolic blood pressure, and blood glucose.[reference|url=https://pubmed.ncbi.nlm.nih.gov/35331862|title=Effect of supplementation with Chlorella vulgaris on lipid profile in adults: A systematic review and dose-response meta-analysis of randomized controlled trials.|published=2022-Jun|authors=Sherafati N, Bideshki MV, Behzadi M, Mobarak S, Asadi M, Sadeghi O|journal=Complement Ther Med|][reference|url=https://pubmed.ncbi.nlm.nih.gov/29037431|title=Effect of Chlorella supplementation on cardiovascular risk factors: A meta-analysis of randomized controlled trials.|published=2018-Dec|authors=Fallah AA, Sarmast E, Habibian Dehkordi S, Engardeh J, Mahmoodnia L, Khaledifar A, Jafari T|journal=Clin Nutr|]

The blood-glucose-lowering effects of chlorella may be due to its ability to improve insulin sensitivity and glucose uptake in the liver and skeletal muscles;[reference|url=https://pubmed.ncbi.nlm.nih.gov/15964314|title=Potential hypoglycemic effects of Chlorella in streptozotocin-induced diabetic mice.|published=2005-Jul-15|authors=Jong-Yuh C, Mei-Fen S|journal=Life Sci|][reference|url=https://pubmed.ncbi.nlm.nih.gov/16289560|title=Improving glycogenesis in Streptozocin (STZ) diabetic mice after administration of green algae Chlorella.|published=2006-Feb-09|authors=Cherng JY, Shih MF|journal=Life Sci|] these effects may be more potent when chlorella is combined with exercise training.[reference|url=https://pubmed.ncbi.nlm.nih.gov/30928787|title=Effect of combination of chlorella intake and aerobic exercise training on glycemic control in type 2 diabetic rats.|published=2019|authors=Horii N, Hasegawa N, Fujie S, Uchida M, Iemitsu K, Inoue K, Iemitsu M|journal=Nutrition|] Certain constituents of chlorella bind to digested dietary fat, increase the scavenging of LDL cholesterol, and reduce the absorption of sterols in the intestine, explaining chlorella’s cholesterol-lowering effects.[reference|url=https://pubmed.ncbi.nlm.nih.gov/24920270|title=Impact of daily Chlorella consumption on serum lipid and carotenoid profiles in mildly hypercholesterolemic adults: a double-blinded, randomized, placebo-controlled study.|published=2014-Jun-11|authors=Ryu NH, Lim Y, Park JE, Kim J, Kim JY, Kwon SW, Kwon O|journal=Nutr J|][reference|url=https://pubmed.ncbi.nlm.nih.gov/15850594|title=Preventing dyslipidemia by Chlorella pyrenoidosa in rats and hamsters after chronic high fat diet treatment.|published=2005-May-13|authors=Cherng JY, Shih MF|journal=Life Sci|][reference|url=https://pubmed.ncbi.nlm.nih.gov/35321288|title=Algae Supplementation for Exercise Performance: Current Perspectives and Future Directions for Spirulina and Chlorella.|published=2022|authors=Gurney T, Spendiff O|journal=Front Nutr|]

Chlorella has exhibited detoxifying effects. It inhibited the intestinal absorption of dioxins (environmental contaminants and pollutants) in animal models and the absorption of heterocyclic amines in humans.[reference|url=https://pubmed.ncbi.nlm.nih.gov/10460212|title=Chlorella accelerates dioxin excretion in rats.|published=1999-Sep|authors=Morita K, Matsueda T, Iida T, Hasegawa T|journal=J Nutr|] Chlorella also reduced mercury levels in the hair and blood of healthy adults.[reference|url=https://pubmed.ncbi.nlm.nih.gov/25590673|title=Detoxification of chlorella supplement on heterocyclic amines in Korean young adults.|published=2015-Jan|authors=Lee I, Tran M, Evans-Nguyen T, Stickle D, Kim S, Han J, Park JY, Yang M|journal=Environ Toxicol Pharmacol|][reference|url=https://doi.org/10.2131/fts.5.117|title=Chlorella supplementation decreases methylmercury concentrations of hair and blood in healthy volunteers|authors=Maruyama et al.|journal=Fundamental Toxicological Sciences|published=2018]

What else is Chlorella known as?
Note that Chlorella is also known as:
  • Chlorella pyrenoidosa
  • Chlorella vulgaris
  • Chlorella sorokiniana
  • Green algae
Dosage information

In the scientific literature, the total daily dose of chlorella ranges from 6 to 10 grams per day. Although there aren’t clear reasons for this range, it appears to be somewhat effective. Higher doses have not been sufficiently tested, and the optimal dose of supplemental chlorella is not known.

For exercise performance, most studies use a dose of 6 grams per day for 3–4 weeks, although emerging research suggests that even a single acute dose (6 grams) of chlorella increases plasma levels of lutein, beta-carotene, and zeaxanthin for up to 72 hours.[1]

Doses of up to 10–15 grams per day appear to be safe. Cardiovascular benefits have been observed with 4 grams per day, and more than 1.5 grams per day seems to be necessary to benefit glycemic control in type 2 diabetes.[2]

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References
  1. ^Serra AT, Silva SD, Pleno de Gouveia L, Alexandre AMRC, Pereira CV, Pereira AB, Partidário AC, Silva NE, Bohn T, Gonçalves VSS, Real G, Escudero P, Fernández N, Matias AA, Bronze MRA Single Dose of Marine Increases Plasma Concentrations of Lutein, β-Carotene and Zeaxanthin in Healthy Male Volunteers.Antioxidants (Basel).(2021-Jul-22)
  2. ^Amir Mehdi Hosseini, Seyed Ali Keshavarz, Ensieh Nasli-Esfahani, Fatemehsadat Amiri, Leila JananiThe effects of Chlorella supplementation on glycemic control, lipid profile and anthropometric measures on patients with type 2 diabetes mellitusEur J Nutr.(2021 Feb 2)
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