"Green foods" include chlorella, spirulina, blue-green algae, barley grass, and wheat grass. [1, 2] Chlorella and spirulina are types of green algae that are taken as supplements in capsule, softgel capsule, tablet, granule, or liquid form or in special types of pasta. Blue-green algae are available as supplements. Barley grass and wheat grass, which are types of grasses, are available fresh or as supplements.
Green foods have many nutritional and health benefits. For example, chlorella, a one-celled plant, is rich in protein, chlorophyll, carotenoids, other vitamins, minerals, and omega fatty acids. [1-4] Chlorella has been termed, "the great normalizer," due to its ability to re-balance disturbed functions of the body.
Based on interpretation of studies conducted mostly in the laboratory and in animals, integrative medicine experts believe that the benefits of chlorella include assisting in following functions, which may help prevent and aid in the treating of various types of cancers and other diseases: [1-6]
Prevent the action of chemicals that could otherwise cause cancer
Inhibit the growth of cancer cells
Boost the immune system
Due to enhancement of the immune system, improve the length of survival in studies in breast cancer, leukemia, and recipients of chemotherapy
Detoxify the body
Protect the lining of the stomach from side effects of drugs and irritants; improves ulcers in the stomach
Protect DNA in normal cells against damage caused by radiation
Aid digestion of food
Promote the growth of normal flora (microbes) in the intestinal tract
Reduction of symptoms in patients with chronic viral (e.g., Epstein-Barr virus or herpes simplex virus) infections
Maintain the health of the liver
Speed wound healing and tissue repair via topical application or supplementation in diet
Chlorella's ability to boost the immune system includes: [1-6]
Increasing the amount of natural killer immune cells that fight abnormal cells
Enhancing the action of other T cells in lymph nodes against abnormal cells
Increasing the amount of B cells, the antibody-producing cells
Enhancing the amount of macrophages (another type of white blood cell)
Promoting the production of gamma interferon and interleukin-1-alpha
Improving length of survival in studies in breast cancer, leukemia, and recipients of chemotherapy recipients
The ability to bind to and remove heavy metals from fluids or tissues is called chelation. Substances that bind to and remove heavy metals from fluids or tissues are termed chelators or chelating agents.
Chlorophyll and the fibrous part of chlorella have the ability to remove the following types of harmful chemicals from the blood, spleen, liver, and other tissues:[1-6]
Heavy metals (e.g, mercury, lead, cadmium, and arsenic)
Pesticides (e.g., DDT)
Other chemical toxins (e.g, PCB)
For example, in people taking chlorella supplements to reduce the level of mercury in their bodies, the mercury from tissues enters the intestine and is excreted in the feces. 
Based on interpretation of studies conducted mostly in the laboratory and in animals, integrative medicine experts also think that the benefits of chlorella include assisting in the following functions, which may help prevent or reduce the symptoms of other diseases: [1-6]
Prevent atherosclerosis in blood vessels
Increase level of hemoglobin in anemia
Lower elevated levels of LDL ("bad") cholesterol and triglycerides
Raise level of HDL ("good") cholesterol
Normalize blood pressure
Reduce arrhythmia (abnormal rhythms of the heart)
Normalize level of blood sugar in hypoglycemia and diabetes
Aid ability for mental concentration
Improve mental ability in Alzheimers disease and other dementias
Improve symptoms of attention deficit disorder
Reduce symptoms of asthma
Reduce symptoms of arthritis
Reduce symptoms of gout
Prevent bad breath
Raise level of physical energy
Reduce symptoms of fibromyalgia in patients in a clinical study
Although chlorella has many benefits, some people using chlorella may experience certain of the following side effects [1, 6]:
Sensitivity to sunlight
Gas, abdominal cramping, constipation, diarrhea, or nausea. Approximately one-third of people taking chlorella supplements do not tolerate it due to these gastrointestinal side effects. However, supplementation with cellulase may aid digestion of chlorella and help reduce these side effects of chlorella.
Fatigue, lethargy, or emotional irritability. These symptoms may be side effects of elimination of heavy metals from the body.
Due to the high content of vitamin K in chlorella, interference with the effects of the anticoagulant, coumadin (warfarin), can occur. If you are taking coumadin, consult your physician before considering taking chlorella or other green foods.
Suggested doses of chlorella range from 3 to 30 grams daily, depending on the medical purpose. [4. 6] Consult your integrative medicine physician and nutritionist to determine whether supplementation with chlorella or other green foods is right for you.
1. Chlorella. PDR Health. Accessed at www.gettingwell.com/drug_info/nmdrugprofiles/nutsupdrugs/chl_0068.shtml.
2. M. Adams. UCB Wellness Letter authors remain nutritionally illiterate about chlorella, spirulina, and blue-green algae. Accessed at www.newstarget.com/001697.html.
3. Chlorella. Tuberose Natural Healing Store Accessed at www.store.yahoo.com/helthequip-store/nabach.html.
4. Chlorella. Accessed at http://watershed.net/chlorella.htm
5. Chlorella. Troubled Times. Accessed at www.zetatalk.com/food/tfood27t.htm
6. J Mercola. Chlorella: A natural wonder food. Accessed at www.mercola.com/chlorella.