Chlorella supplement health benefit and side effects, review of medical uses and influence on immune system by Ray Sahelian, M.D.
October 28 2014

Chlorella is a green algae that grows in fresh water. It emerged over 2 billion years ago, and was the first form of a plant with a well-defined nucleus. Each Chlorella microorganism is composed of a nucleus, starch grains, chloroplasts and mitochondria surrounded by a cell wall composed mainly of cellulose. Because it is a microscopic organism, it was not discovered until the late 19th century, deriving its name from the Greek, "chloros" meaning green and "ella" meaning small. There are various species. Although the algae grow naturally in fresh water, chlorella destined for human consumption is generally cultivated in large, fresh mineral water pools under direct sunlight. It is a tiny, unicellular green algae, three to eight micrometres in diameter, which when grown in large quantities gives lakes and rivers a green tint.
   Although it was discovered by a Dutch microbiologist in 1890 and studied as a potential protein source by German scientists, it wasn't until after the Second World War that the reality of food shortages, combined with the expectation of a population boom, led to bureaucrats globally examining chlorella in the hope that it could be used to feed the masses cheaply Ė this proved uneconomic. Later, NASA studied it with the possibility of feeding it to astronauts. It is currently being used in some countries to help cancer patients.

What does the research say about the benefits?
I could only find a few studies with chlorella involving humans. Based on very early research, it appears that it may play a role in fibromyalgia, hypertension, or ulcerative colitis and has an effect on the immune system. We definitely need a few more studies to confirm initial findings.

Purchase Chlorella supplement, 500 mg per pill
Chlorella is a green single-celled microalgae that contains very high concentrations of chlorophyll. Before being used as a supplement, it must be gathered, dried to a paste, crushed to a fine emerald green powder, and converted to tiny, soft, crumbly tablets, which smell vaguely of the sea. It supplies high levels of beta carotene, vitamin B-12, Iron, RNA, DNA and Protein. The cell wall in this high quality chlorella has been broken down mechanically to aid digestibility. Each serving typically contains: Chlorophyll 25 mg, RNA 35mg and DNA 3mg.

Supplement Facts
Chlorella Powder 500 mg per capsule (Chlorella vulgaris)



Purchase chlorella supplement

What is the difference between chlorella broken cell and the unbroken cell version?
   The outer cell wall of chlorella has a low digestibility, which requires an opening to digest its nutrients. A variety of methods are used by different makers to break down the cell wall to enhance its digestibility. The broken cell version will have a higher absorption rate than the unbroken cell.

Helps improve overall health
Japanese researchers claim that this green algae could reduce body-fat percentage and blood-glucose levels and help those who have type 2 diabetes, obesity, cancer patients or those with heart disease. This supplement could boost energy and improve mood. Some claim that chlorella stimulates the growth of probiotic or friendly bacteria, and its cell walls absorb toxins within the intestine and encourage peristalsis. Randall Merchant, professor of Neurosurgery and Anatomy at Virginia Commonwealth University, in the US, researches brain tumors, traumatic brain injury, and stroke. In 1986, he began clinical trials, funded by chlorella producer Sun Chlorella 'A', into whether the algae might improve a patient's immune system. "Fascinating," is how he describes the results. "It didn't make brain tumours go away or shrink, so it didn't cure the cancer, but it did help the patients by boosting their immune system so that they resisted opportunistic infections." Since then, Prof Merchant has performed clinical trials to test whether chlorella could be useful in helping with chronic conditions such as fibromyalgia, ulcerative colitis and hypertension. In the first two trials, his team found that "patients' symptoms diminished quite nicely". For hypertension, the results were more dramatic; while it lowered blood pressure in about 50 per cent of cases, which was promising, the studies showed that it also significantly lowered serum cholesterol. In 2008, he examined the effects chlorella has on those with metabolic syndrome Ė the collection of symptoms that often lead to the cells in our bodies becoming less sensitive to insulin, and therefore a precursor to diabetes. Chlorella turns on the genes that control the way insulin is normally used by the cells in the body and may be of benefit to those with metabolic syndrome.

Antioxidant benefit and eye health
Consumption increases levels of antioxidants in the bloodstream.

Antioxidant and anti-cataract effects of Chlorella on rats with streptozotocin-induced diabetes.
J Nutr Sci Vitaminol 2003.
A 7% Chlorella powder was fed to rats with streptozotocin-induced diabetes for 11 weeks. At the end of the experiment, chlorella had decreased the blood glycated hemoglobin (hemoglobin A1c) and serum cholesterol levels significantly, however, it had not affected the serum glucose concentration. The serum lipid peroxide value (TBARS value) in the rats fed chlorella was lower than that of the control rats. In the liver and kidney, Chlorella also reduced chemiluminescent intensities. In addition, it delayed the development of lens opacities. These results indicate that chlorella has antioxidant activity and may be beneficial for the prevention of diabetic complications such as cataracts.

Attenuating effect of chlorella supplementation on oxidative stress and NFkappaB activation in peritoneal macrophages and liver of C57BL/6 mice fed on an atherogenic diet.
Biosci Biotechnol Biochem. 2003.
Our results suggest that chlorella supplementation may attenuate oxidative stress by reducing reactive oxygen production and increasing antioxidative processes, thus suppressing inflammatory mediator activation in peritoneal macrophages and liver.

Fibromyalgia
Nutritional supplementation with Chlorella pyrenoidosa for patients with fibromyalgia syndrome: a pilot study.
Phytother Res. 2000.
The objective of the present study was to determine if adding nutritional supplements derived from the unicellular green alga, Chlorella pyrenoidosa, produced any improvements in the clinical and functional status in patients with moderately severe symptoms of fibromyalgia syndrome. Each day for 2 months, participants consumed two commercially available products, 10 g of 'Sun Chlorella' tablets and 100 mL of liquid 'Wakasa Gold'. There was a 22% decrease in pain intensity. Blood samples taken on each occasion indicated no significant alterations in serum chemistries, formed elements, and circulating lymphocyte subsets. Seven patients felt that the dietary supplement had improved their fibromyalgia symptoms, while six thought they had experienced no change, and five believed the symptoms had worsened over the time of the trial. The results of this pilot study suggest that dietary Chlorella supplementation may help relieve the symptoms of fibromyalgia in some patients and that a larger, more comprehensive double-blind, placebo-controlled clinical trial in these patients is warranted.

Smoking damage
Clin Lab. 2013. Investigation of the effects of Chlorella vulgaris supplementation on the modulation of oxidative stress in apparently healthy smokers. Supplementation with C. vulgaris extract significantly improves antioxidant status and attenuates lipid peroxidation in chronic cigarette smokers. Hence, C. vulgaris might prevent the disease burden and mortality rate associated with smoking.

Chlorella side effects, safety, risk, toxicity, nausea appears to be common
Although no significant chlorella side effects have been reported in the medical literature, we have had several reports of gastrointestinal side effects with the use of such supplements. These chlorella side effects involved nausea and vomiting and I have listed some of the emails we have received.

October 2014 - I read your article on chlorella and the feedback of so many that experienced the same as I do with the power vomiting, more severe than when a stomach virus! Has anyone figured out why this occurs? I have had people tell me just to not take it, which I donít as just a mouthful of a mixture of herbs, greens including the tiniest amount of chlorella makes me vomit for hours, others have said to take cellulase enzymes with it, which Iíve found hasnít worked either. It would be great to find out why it has this reaction, hoping you can help clarify why.
   A. I really do not know why this adverse effect occurs.

February 2014 - I started taking chlorella by Source Naturals Yaeyama about two weeks ago and yesterday experienced violent vomiting. It took 24 hours to recover. Since this seems to be a common experience, I won't be trying it again.

I started taking a chlorella supplement several weeks ago. I did not take them everyday. Last Monday I took Chlorella about an hour after I ate lunch. Within 3 hours I had an upset stomach and threw up several time that night. The next day I was alright. I did not take chlorella for the rest of the week due to I thought that it may have something to do with my sickness. Yesterday, a week later I decided to try chlorella again. This time I took it right after I ate. within in three hours I was violently sick. I was throwing up every 2 to three seconds. It was so bad I got dehydrated within an hour and was so disoriented that an ambulance had to pick me up to take me to the Hospital, By this time the Paramedics said I was throwing up a lot of bile. The doctors at the emergency room told me that it was more likely a reaction to the chlorella. Has anyone else had these kind of side affects? I do not even take the complete recommended dosage. What could have caused such a reaction. I have had stomach viruses before. This was the worst thing that I have ever had. I thought I was dying. How can something that is suppose to be good for you cause such a reaction? The brand is Source Naturals Yaeyama Chlorella. It had just vitamins in it and mixed carotenoids.

I tried it on two different occasions and vomited for a least an hour after taking the chlorella supplements. I thought that I was the only one who had this experience because I hadn't seen any comment or questions like this before concerning chlorella pills. I'm quite sure there are several other people who have had this experience with chlorella pills.
   This is the second report we have had regarding vomiting side effect after taking chlorella supplements.

I took it in powder form for about 2 weeks. It seemed to agree with me then one day I took it and within one hour I was experiencing the worst case of what felt like food poisoning you can ever imagine. Severe vomiting and diarrhea for several hours. I waited about a week to try again( not believing it could possibly be this wonderful food supplement that I was so impressed by initially) and sure enough the same thing happened. Still, I was undaunted and a week later I tried again but this time I took only 1/8th of a dose. Within one hour once again I was vomiting and the day was ruined due to the fatigue of just getting it out of my system. I am stymied by this and now I'm concerned about what might be causing me to reject it. I have no known diseases or conditions. The chlorella product I took is reputable (Sequel) and has been stored properly.

I just wanted to add my two cents to the issue of immediate sickness and side effect after taking chlorella supplement. I was reading your chlorella supplement questions site, and noted a couple of people had been violently ill when taking it. This has also happened to me, more than once first when taking a chlorella supplement prescribed by my naturopath and then yesterday) when unknowingly drinking a fruit smoothie that contained chlorella. The sickness was debilitating vomiting, diarrhea, etc. and left me on the bathroom floor for four hours. Someone should do chlorella studies on this effect, as it appears Iím not the only one.

In the past I was able to take it with no problem (NOW chlorella powder). But when I tried it a few weeks later, I vomited all day and was very, very sick. Then I tried it again about a week later and the same thing happened. I don't know if I became allergic to it, or what, but I won't take any type of chlorella now.

I just want to report vomiting violently several hours after taking chlorella supplements - this happened two times and I will never use it again. As in one of the comments on your site an ambulance was called one time. In my experience the chlorella applies itself systemically - I felt sensations from the head to the feet. It also moves one into an altered state of consciousness, the kind of state one enters any time one is quite ill. The brand I used was BioPure. I had another brand a while back and never had any problem with it.

I am witting you to report to you how very ill I became after taking chlorella supplement. The first time I took it the response was delayed (24-48 hours, after I first started). The next time, I tried it, it was only a matter of 4 hours or so, before I was violently vomiting. It took about 24 hours to recover, each time.

I have experienced gastrointestinal upset. I have tend to have a sensitive bowel, but thought that chlorella was beneficial for this. Also I suffer from fibromyalgia and migraine. I had tried a year ago New Chapter Chlorella on one occasion and do not recall having any problems. However, when I bought and took two tablets of brand called Organika I got sick on two occasions. The first time I got severe nausea and flu like symptoms within a few hours of taking two tablets. Miraculously, drinking ginger tea cleared up the symptoms quite quickly. I tried the Organika Chlorella a week later just in case it wasn't the supplement that had made ill. Again within a few hours, I wasn't nauseous, but I had severe cramps and then diarrhea, which fortunately was short lived. (email received March 2009)

I started taking chlorella and got a really stuffed nose. I suspected it was the chlorella, and as soon as I stopped taking it I could breathe again! Thought you might want to add this to your side effects testimonials.

I started taking Chlorella for the first time about 5 weeks ago, Kyoto brand. Iíve been taking several supplements over the past few years for my inflammatory bowel disease-like symptoms that have helped me a lot. I started with just 1 three times per day and over the first few weeks gradually increased it to 5 tablets 3 times per day, with 15 tablets containing 3 g of chlorella. I felt great the first few weeks, had better improvement in my symptoms than anything I tried before, but then started having uncontrolled racing thoughts involving past memories, trouble concentrating, irritability and a hyper feeling. The end of last week I started having watery diarrhea, loose stools, stomach cramping, mild headache, trouble sleeping and a panicky feeling that may have been stress from all this. I had slight nausea and chills, but no vomiting. It was getting harder to eat. I was getting fatigued from not eating and sleeping. I donít take prescription drugs, only the natural supplements Iíve been taking a long time. I researched and found on your website and a few others that it can cause the GI symptoms with some people. I donít know about the mental symptoms, but they came together and never happened before. I noticed the dose you recommend is much smaller than what I have been taking, so I am going to stop it for a few days, then start very slowly up to the small dose I was taking before these symptoms started. I would like to keep taking it if I can for the benefits. Iím not putting down supplements, Iíve taken them for years with great success, but I donít agree with some who say that because itís a natural food supplement it can only have positive effects and no bad side effects. There are many substances found in nature that can have both positive and negative effects on us and vary with different people. (email received October 2011). All of my symptoms were completely gone by the second day after stopping and havenít returned.

After taking it for about 2 weeks without any ill effects, I started having the following symptoms: diarrhea, extreme thirstiness, and mild vertigo. I did some internet research yesterday and discovered similar symptoms being talked about on your website. I read on another site that impurities in the chlorella (from how it's grown and manufactured) could cause problems. I also understand that there are elements of the organism itself that could cause problems - the LPS that is part of the cell wall of chlorella may trigger immune system responses that lead to systemic inflammations.

Pregnancy
I am not aware of studies that have reviewed this supplement in terms of its safety during pregnancy.
 

Chlorella Research study
Effects of chlorella on activities of protein tyrosine phosphatases, matrix metalloproteinases, caspases, cytokine release, B and T cell proliferations, and phorbol ester receptor binding.
J Med Food. 2004.
A Chlorella powder was screened using 52 in vitro assay systems for enzyme activity, receptor binding, cellular cytokine release, and B and T cell proliferation. The screening revealed a very potent inhibition of human protein tyrosine phosphatase activity of CD45 and PTP1C. Other inhibitory activities and their IC(50) values included inhibition of the human matrix metalloproteinases and the human peptidase caspases, as well as release of the cytokines interleukin (IL)-1, IL-2, IL-4, IL-6, interferon-gamma, and tumor necrosis factor-alpha from human peripheral blood mononuclear cells. Chlorella also inhibited B cell proliferation in mouse splenocytes and T cell proliferation in mouse thymocytes. These results reveal potential pharmacological activities that, if confirmed by in vivo studies, might be exploited for the prevention or treatment of several serious pathologies, including inflammatory disease and cancer.

A hot water extract of Chlorella pyrenoidosa reduces body weight and serum lipids in ovariectomized rats.
Phytother Res. 2004.
The effects of a hot water extract of Chlorella pyrenoidosa, which contains chlorella growth factor, on the body weight, serum lipids, and the bone mass were evaluated using an ovariectomized rat as a model for postmenopausal bone loss. Rats were divided into four groups: sham-operated (Sham), Sham given the chlorella growth factor solution, ovariectomized (OVX), and OVX given the chlorella growth factor solution, respectively. Administration of the extract to OVX rats suppressed the body weight gain. After 7 weeks, the administration of the extract to the OVX group reduced increases in both serum total cholesterols and high-density lipoprotein (HDL) cholesterols. It also normalized the decrease of triglyceride level in the OVX group. The ovariectomy decreased the tibial bone mineral density (BMD) by 19%, and the administration of the extract to OVX rats did not inhibit this decrease. These results suggest that a dietary supplement of chlorella growth factor may be useful to control the body weight and improve lipid metabolism of menopausal women.

I am currently a student at Great Neck South High School in New York. I have read your site about the health benefits and was wondering if you knew where I could buy the algae Chlorella pyrenoidosa. I need this to do an experiment on whether it really does have hypoglycemic properties.
   It appears that Sun Chlorella brand has this particular genus. You can google Sun Chlorella and find an online store that sells it.

Accumulation of astaxanthin and lutein in Chlorella zofingiensis (Chlorophyta).
Appl Microbiol Biotechnol. 2004.
When grown photoautotrophically, Chlorella zofingiensis strain CCAP 211/14 accumulates a significant amount of valuable carotenoids, namely astaxanthin and lutein, of increasing demand for use as feed additives in fish and poultry farming, as colorants in food, and in health care products.

Safety and immunoenhancing effect of a Chlorella-derived dietary supplement in healthy adults undergoing influenza vaccination: randomized, double-blind, placebo-controlled trial.
CMAJ. 2003.
We evaluated the effect of an oral dietary supplement derived from the edible microalga Chlorella pyrenoidosa on immune response after influenza vaccination. We conducted a randomized, double-blind, placebo-controlled community-based clinical trial in a convenience sample of 124 healthy adults at least 50 years of age randomly assigned to receive the study product (200 or 400 mg of a Chlorella-derived dietary supplement) or placebo. Participants took the study product or placebo once daily for 28 days. On day 21, we administered a single dose of a licensed trivalent, inactivated influenza vaccine. We obtained serum specimens to measure hemagglutination inhibition titres before and 7 and 21 days after vaccination. The primary immunological outcomes were the proportion of participants with a 4-fold or greater increase in antibodies and geometric mean antibody titres after vaccination.There were no differences in the proportions of recipients of 200 or 400 mg of the Chlorella -derived dietary supplement or placebo who achieved at least a 4-fold increase in antibodies (proportions for the 3 virus strains ranged from 17% to 28% for the 200-mg group, from 11% to 22% for the 400-mg group and from 19% to 21% for the placebo group. Reports of adverse events were similar for recipients of the supplement and placebo, except with regard to fatigue, which was reported more frequently by recipients of 200 mg of the supplement (18/41 or 44%) than by those who received 400 mg of the supplement or placebo. Recipients of 400 mg of the chlorella supplement who were 55 years of age or younger had significantly higher geometric mean antibody titres against influenza A/New Caledonia 21 days after vaccination and against B/Yamanashi 7 days after vaccination; the trends were nonsignificant for titres against A/Panama. We also observed similar increases for the proportions of subjects with a 2-fold or greater or a 4-fold or greater increase in antibodies. The Chlorella derived dietary supplement did not have any effect in increasing the antibody response to influenza vaccine in the overall study population, although there was an increase in antibody response among participants aged 50-55 years. Adverse events were similar among those receiving the supplement and the placebo.

A review of recent clinical trials of the nutritional supplement Chlorella pyrenoidosa in the treatment of fibromyalgia, hypertension, and ulcerative colitis.
Altern Ther Health Med. 2001.
It has been suggested that the consumption of natural "whole foods" rich in macronutrients has many healthful benefits for those who otherwise ingest a normal, nonvegetarian diet. One example is dietary supplements derived from Chlorella pyrenoidosa, a unicellular fresh water green alga rich in proteins, vitamins, and minerals. To find evidence of the potential of chlorella dietary supplements to relieve signs and symptoms, improve quality of life, and normalize body functions in people with chronic illnesses, specifically fibromyalgia, hypertension, and ulcerative colitis. Fifty-five subjects with fibromyalgia, 33 with hypertension, and 9 with ulcerative colitis. Subjects 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. For fibromyalgia patients, assessments of pain and overall quality of life. For hypertensive patients, measurements of sitting diastolic blood pressure and serum lipid levels. For patients with ulcerative colitis, determination of state of disease using the Disease Activity Index. Daily dietary supplementation with chlorella may reduce high blood pressure, lower serum cholesterol levels, accelerate wound healing, and enhance immune functions. The potential of chlorella to relieve symptoms, improve quality of life, and normalize body functions in patients with fibromyalgia, hypertension, or ulcerative colitis suggests that larger, more comprehensive clinical trials of chlorella are warranted.

Different brands
There are various chlorella products on the market, including Sun Chlorella. I am not familiar with the different brands of chlorella and thus do not know if Sun Chlorella is better than other brands.

Questions
Q. I read somewhere that chlorella removes toxins from the body. Is that true? Also, I read that one needs to check their blood iron level before taking chlorella.
   A. When people talk in such vague terms as 'toxins,' it makes me think that either they do not understand the complexity of the human body, or they are just scammers, trying to hype their product. I have not seen any studies where chlorella was found to remove 'toxins' from the body. How are these 'toxins' defined, anyway? It makes no sense to me that one has to check their iron level before taking chlorella. It's like saying one has to check their iron level before eating meat products. There are several milligrams of iron in a few ounces of meat. Three capsules of chlorella will have less than one mg of iron.

Q. Dear Dr. Sahelian: Since you are a respected authority whose input and knowledge I respect, I wanted to ask: In your opinion, does chlorella have any value as a memory enhancement supplement? The flyer from Sun Chlorella claims that a study where seniors took10 a day of their Sun Chlorella pills, in addition to the liquid extract, proved that it has memory enhancing properties. Have you had any experience with Sun Chlorella? I think its probably a pretty good detoxifier. But I've never heard you mention it. I love the products you formulate and have just finished reading your Mind Boosters book. Thank you for your time.
   A. We have searched Medline and could not find studies with Sun Chlorella and memory. Even if there were one study that showed some benefit, it would pale in comparison to the many studies done with other brain nutrients that are discussed in the Mind Boosters book. Chlorella, in moderation, appears to be a healthy addition to one's diet and supplement intake, however it is one of countless other beneficial supplements that are available.

I am a healthy 19 year old who participates in sports including lacrosse and kung fu. I have recently been introduced to the health benefits of chlorella and spirulina, but I'm on a student's budget (one who's putting himself through a big university) and even though I'd like to take both, I have to choose. I was just wondering if there are certain reasons why I should take one over the other (spirulina versus chlorella).
   I am a believer in ingesting a variety of supplements rather than the same one(s) all the time. As such it may be a good idea to take spirulina first, once the bottle is finished to take a week off, and then take a chlorella supplement. It is a good idea to take breaks in between.

I read your post on the chlorella page some saying they got sick. I have been taking chlorella for years along with my wife, my two brothers, their wives, my parents and at least 20 friends and acquaintances. No body I know has ever been sick. Since chlorella and spirulina are a food, not supplements, (there is nothing added to pure chlorella and spirulina), that's like trying to say I vomit violently from eating green beans. I know that the drug cartels (prescription drugs that is) go to great lengths to suppress anything like chlorella and spirulina as many people find it does make them very healthy. Speaking for myself and all the people I know, it does make a huge difference in our life and health. Now I did do quite a bit of research on chlorella and did find that there are good manufactures and ones you really should stay away from because of contaminates in their product. My wife suffers from migraines. After taking chlorella and spurulina (10 grams a day each) she had not suffered a disabling migraine (it used to happen at least once a month). Now she may get headaches but they are handled with Tylenol and such. Coincidence? Maybe but I think not. She stopped taking this stuff for about a month and suffered a disabling migraine for the firs time in two years. I told her to get back into the routine and she has been fine since. Anyway, I took the time to write this because I really have seen the benefits of chlorella and spurulina.

 I have about a tablespoon of chlorella powder everyday. I had previously read that it's a "food" and that you can't eat too much. Now I've seen warnings on another health website that over-use of chlorella can lead to excessively high iron levels.
    As with most supplements, it is a good idea to take breaks from use.

I was reading your section on chlorella and saw the abundance of reader comments on several reactions after ingesting chlorella. I also noticed the absence in your comments and research citations of the profound role of chlorella in heavy metal chelation. Chlorella is an essential oral chelator. There is much research on this. It would be a great service to readers if this could be addressed on your site and research could be posted. I think that the reactions people were experiencing have to do with the heavy metal toxic burden being mobilized and reabsorbed or redistribution. I personally experienced a difficult reaction to chlorella - similar to what other readers described - when taking it for heavy metal chelation. I have read that higher doses should be taken in such cases, as more chlorella is needed to sufficiently bind to the metals it mobilizes.
    I have not seen human studies regarding the role of this supplement in terms of chelating heavy metals. Some people think such reactions are due to chelation, but that may not necessarily be so. I question the wisdom of taking more in such cases of getting these unpleasant reactions or side effects.

More information
Chlorella pyrenoidosa, one of the oldest foods on the planet, is a single-celled plant that grows in fresh water and is about the same size as a human blood cell. It is a green algae, drawing its color from an unusually high amount of chlorophyll (more than any other known plant!). It is grown commercially on water farms, where pure water, clean air, and bright sunlight encourage growth, and special centrifuge equipment is used for harvest. It multiplies quickly, with a complete reproductive cycle every 20 hours.