Recent research has found out that apart from being full of healthy nutrients, it also has several health-benefiting compounds which make it a functional food too.
These properties make the consumption of this superfood even more worthwhile.
There are various species of Spirulina, the most common being Anthrospira platensis and Anthrospira maxima.
It can grow in both salty and fresh waters and is now even being cultivated in laboratories for commercial and nutritional use. It grows best in alkaline and warm climates.
Commonly, it is dried and ground into powder form for consumption, but can also be eaten raw.
The nutrient storehouse of this microbe includes proteins, B-complex vitamins, vitamin E, minerals, healthy fats and antioxidants.
Let us have a detailed insight into the benefits of Spirulina on human health, all backed by scientific evidence.
Health Benefits of Spirulina
Below mentioned are the various ways in which Spirulina can affect your health positively.
1. Spirulina is Extremely Nutritious
The nutritional composition of Spirulina includes proteins (60-70%), lipids (8%), carbohydrates (24%) and fibre (3.6%).
It is one of the richest protein sources among seaweeds, and its protein content is comparable to that of meat and soybeans.
Spirulina has been used to treat protein deficiency and prevent its complications. In a study, it was found that Spirulina was able to avoid bone growth delay and liver disturbances that occur due to protein deficiency. 
Sodium, potassium, calcium, zinc, iron, magnesium, copper and selenium are some of the significant mineral constituents.
These minerals are available in bioavailable forms which makes it utilisation by the human body, even easier. 
Journal of Agriculture and Food Chemistry reports that Spirulina has high iron availability, comparable to that of beef, and could be used as an adequate iron source. 
Vitamin C, vitamin E, vitamin K, vitamin A, folates and B-complex vitamins are also present in significant amounts in Spirulina. 
Vitamin B12, which is mostly found in animal-based protein, is present in Spirulina in substantial amounts, which makes it an excellent source of this vitamin for vegetarians and vegans. 
With such an impressive nutritional profile, regular intake of Spirulina in diet, as a food supplement could provide the following benefits:
- Improve the nutritional status, performance, and body weight 
- Prevent several vitamin and mineral deficiency diseases
- Counteract malnutrition in children and elderly 
- Act as a dietary supplement in people suffering from diseases and conditions which deplete the nutrient reserve, like HIV.   
What does this Mean? Spirulina can serve as an exceptional nutritional supplement for everyone, particularly the children, elderly and those suffering from nutritional deficiencies.
2. Spirulina Alleviates Metabolic Syndrome
Metabolic syndrome refers to a number of metabolic abnormalities. This includes disrupted levels of blood glucose, cholesterol, body fats, blood pressure, and unhealthy body weight.
These, if left untreated could lead to the development of other disorders and complications like diabetes, obesity and cardiovascular ailments.
It further decreases the concentrations of cholesterol, triglycerides, and LDL-cholesterol, while increasing HDL-cholesterol in the body.  Additionally, it lowers the systolic and diastolic blood pressure levels. 
This helps in keeping cardiovascular problems like atherosclerosis, thrombosis, stroke and heart attack, at bay.
Moreover, the lipid-lowering abilities of Spirulina enable reduction of body fat, preventing fat accumulation in adipose tissues, which contribute to the maintenance of healthy body weight. 
What does this Mean? Spirulina can improve the overall metabolic profile by normalizing the blood pressure, body weight, lipid and glucose levels.
(Read more 5 Proven Benefits of Spirulina in Metabolic Syndrome)
3. Spirulina helps in Management of Diabetes
Diabetes is characterised by the inability of the body to maintain proper blood glucose levels. In type 1 diabetes, the body does not produce insulin.
On the other hand, type 2 diabetes or diabetes mellitus occurs due to inadequate insulin production or abnormal response of the body to the synthesised insulin-called insulin sensitivity.
Diabetes patients usually suffer from hyperglycemia where the blood glucose levels are too high.
Normalizing these levels can enable patients to lead a regular life, without increasing risks of liver, heart and kidney complications.
Spirulina has been proven beneficial in both types of diabetes.
Type 1 diabetes:
Spirulina has anti-inflammatory and anti-oxidant capacities and could successfully reduce the inflammatory mediators like nitric oxide and nuclear factor kappa-B (NF κ-B).
This prevents the development of toxic conditions in the pancreas and helps in preserving the viability and functioning of pancreatic β-cells, which produce insulin.
In studies conducted on animal models, spirulina supplementation led to reduced blood glucose levels, increased insulin concentrations and improved markers of liver functioning enzymes.
Thus, Spirulina could assist in the treatment of type 1 diabetes by preventing or delaying the destruction of insulin-producing cells in the pancreas. 
Type 2 diabetes:
Spirulina is a miracle drug for diabetes mellitus as it could benefit diabetes patients in multiple ways:
- Spirulina can reduce blood glucose and direct the excess glucose to be stored as glycogen in the body. 
- It could prevent pancreatic β cells, which produce insulin, from damage caused by oxidative stress. 
- It lowers insulin resistance which leads to better insulin response and utilisation by the body. 
- There has been a close link between inflammation and diabetes. The anti-inflammatory effect of Spirulina could prevent the development of diabetes due to inflammatory mediators. 
- It improves the loss of body weight. 
- It could normalise lipid, triglyceride and cholesterol concentrations. This helps in the prevention of cardiovascular complications that frequently occur in diabetes patients.
- Spirulina decreases oxidative stress and improves the levels of antioxidants and liver functioning enzymes. This prevents liver damage, toxicity, dysfunction, and complications like non-alcoholic fatty liver disease. 
- It benefits in diabetic nephropathy due to its antioxidant capacities. The pigments in phycocyanin and phycocyanobilin in Spirulina reduce oxidative stress, prevent damage and restore the structure and function of the kidneys.  
Preliminary studies also suggest that that coadministration of Spirulina with the diabetic drug glitazone does not affect the pharmacokinetics and metabolism of the drug by the body.
Thus, it could be safely used as a supplement along with other diabetes medications. 
What does this Mean? Spirulina can assist in maintaining healthy glucose levels by regularising insulin production and sensitivity. It helps in both type 1 and type 2 diabetes and also prevents many diabetic complications.
4. Spirulina Benefits in Obesity
Obesity usually occurs as a result of metabolic disturbances which cause fat to accumulate in the body.
This increases the Body Mass Index (BMI), body weight, waist circumference, lipid levels and also the risk of cardiovascular disorders, non-alcoholic fatty liver disease, arthritis, cancer, and diabetes.
Inflammation and oxidative stress developed due to the accumulation of toxins in the body are known to play a vital role in the development of obesity.
Spirulina can help tackle obesity and prevent its complications.
Szulinska M. et al. reported in a study that Spirulina was able to decrease body weight, BMI, waist circumference, lipid levels, insulin sensitivity, and inflammatory markers while improving the antioxidant status in obese individuals. 
In another study conducted on 64 obese individuals, Spirulina supplementation taken twice daily for three months led to a reduction in body weight, appetite and lipid levels.
This proved its potential to treat obesity and related disorders. 
When the effects of Spirulina in hypertensive obese individuals were studied, improvements in blood pressure levels were also observed. 
Cancer is yet another obesity-related disorder, and with potent anti-cancer properties, Spirulina could be efficiently used as a weight-reduction drug with chemo-preventive effects. 
What does this Mean? Spirulina prevents obesity and benefits obese individuals by lowering body weight, BMI, waist circumference and the risk of obesity-related disorders.
(Read more 6 Science-Backed Benefits of Spirulina in Obesity)
5. Spirulina Normalises the Blood Pressure
Hypertension or high blood pressure in the arteries, if persistent, can cause cardiovascular disorders like stroke, heart failure, and kidney problems.
Various studies have shown that Spirulina can modulate blood pressure levels, and hence prevent heart diseases.
Journal of Agricultural and food chemistry reports a study which examined the long-term effects of Spirulina on hypertension in animal models.
It showed that peptides isolated from Spirulina were successful in lowering both systolic and diastolic blood pressures for a long duration, even after completion of the treatment procedure.
The microalga prevents vascular dysfunction by further decreasing the synthesis or release of substances that cause constriction in blood vessels while increasing the production of substances which enable vasodilation.  
In human studies conducted on hypertensive obese individuals, Spirulina showed similar effects by improving the blood pressure levels and endothelial function (functioning of the blood vessels).  
What does this Mean? Spirulina can lower both systolic and diastolic pressure and maintain proper structure and functioning of blood vessels.
6. Spirulina Lowers Lipid Levels in the Body
Studies show that Spirulina has both lipid-lowering and cholesterol-lowering properties.
Spirulina lowers the concentrations of plasma lipids, mainly triglycerides (TG), total cholesterol (TC) and Low-Density Lipoprotein (LDL) cholesterol while increasing the High-Density Lipoprotein (HDL) cholesterol. 
It is a known fact that LDL-cholesterol is harmful to health and could lead to the development of plaque in arteries, thereby increasing the risk of heart diseases.
On the other hand, HDL-cholesterol or good cholesterol protects against atherosclerosis.
Scientists have also discovered that the novel protein C-phycocyanin in Spirulina is responsible for its cholesterol-reducing effects. 
These hypolipidemic effects of Spirulina have been confirmed in a wide variety of individuals from different populations across the world,  young  and elderly, healthy people and persons suffering from conditions like diabetes mellitus, hypolipidemia, hypercholesterolemia, HIV , nephritic syndrome  or ischemic heart disease. 
We have previously mentioned that Spirulina contains 8% fats. However, the fats in Spirulina are unlikely to raise lipid levels or pose health risks.
When the fatty acid composition of Spirulina was studied, it was found that most of these fats are polyunsaturated fats, with high levels of gamma-linolenic acid, which is good for health. 
What does this Mean? Spirulina ensures optimum concentrations of lipid in the body. It lowers triglycerides, total cholesterol and LDL-cholesterol while elevating the levels of the beneficial HDL-cholesterol.
7. Spirulina Prevents many Cardiovascular Ailments
Blood pressure cholesterol and lipid levels in the body are the primary markers of cardiovascular health.
We have seen in the above sections how Spirulina modulates blood pressure and lipid levels.
Thus it can be said that Spirulina is cardioprotective in nature and could prevent the occurrence of heart ailments like coronary artery disease, stroke, and heart failure. 
Spirulina helps in the following cardiovascular conditions:
Atherosclerosis: By regularising lipid levels and lowering cholesterol, Spirulina prevents deposition of fats, the formation of plaque and atherosclerotic lesions which narrow the arteries. 
It also maintains optimum blood pressure levels which prevent endothelial dysfunction and arterial damage.
Moreover, spirulina activates the heme oxygenase-1 enzyme which assists in the generation of bilirubin.
The antioxidant bilirubin is responsible for removing toxins and waste generated from the destruction of old blood cells, which otherwise could accumulate and clog the arteries. 
Arterial thromboembolism: Studies have also shown that the protein C-phycocyanin present in Spirulina possesses an anti-platelet activity.
It has been identified as a very potent inhibitor of platelet aggregation which can prevent the formation of blood clots.
This, in turn, could avert the occurrence of arterial thromboembolism which occurs due to the obstruction of arteries by blood clots. 
Thrombosis: The polysaccharide Calcium Spirulan in Spirulina demonstrates anti-thrombin activity by inhibiting the enzymes responsible for blood coagulation and clot formation. 
Cardiotoxicity: Cardiotoxicity usually occurs as a side effect of drug usage. Being a potent anti-oxidant, Spirulina has the potential to treat or remove toxins and reverse or prevent the toxicity or damage that might otherwise affect the heart health adversely. 
What does this Mean? By regulating blood pressure and lipid levels, Spirulina prevents risks of heart diseases like thrombosis, atherosclerosis, ischemia, stroke and heart failure.
8. Spirulina has Anti-Inflammatory Properties
Inflammation is the cause of several disorders including arthritis, cancer, inflammatory bowel diseases, neurological problems, and many others.
Inflammation is a natural immune mechanism of the body to fight pathogens and unwanted substances. However, severe or persistent cases of inflammation can cause the formation of toxins as by-products and cause cell and DNA damage.
Many drugs are available to fight inflammation, but they have serious side effects.
Thus, scientists are continuously exploring natural anti-inflammatory agents to assist in the treatment of inflammation-mediated diseases.
There are plenty of scientific references which prove the anti-inflammatory capacity of Spirulina, which makes it a potential agent for the treatment of several inflammatory conditions. 
This property of Spirulina is attributed to the presence of two of its primary active ingredients: Phycocyanin and β-carotene.
They suppress various inflammatory mediators like prostaglandins, cyclooxygenase-2 enzymes (COX-2), Tumor Necrosis Factor-alpha (TNF-α), Nuclear Factor Kappa-B (NF κ-B) and Interleukins (IL-6, IL-12, IL-1B).   
What does this Mean? Spirulina inhibits several components that mediate inflammation in the body. This keeps in check many inflammatory disorders.
9. Spirulina is Anti-Pyretic in Nature
Spirulina can modulate body temperature and thus could contribute to fever reduction. Severe inflammation is usually accompanied by fever.
However, more research is required to confirm this effect in humans.
What does this Mean? Spirulina can regulate body temperature and help treat fever.
10. Spirulina Eases the Symptoms of Arthritis
Arthritis is a common inflammatory condition which results in inflammation and pain in the joints.
This causes reduced functioning and motility of the affected area, which makes it difficult for a person to carry out his/her day-to-day activities.
Spirulina can ease the symptoms in an arthritis patient. Due to its anti-inflammatory activity, Spirulina helps in reducing inflammation and pain in joints.
It increases the number of immune cells, regulates body temperature and increases the mobility of the joints.
What does this Mean? Spirulina reduces inflammation and pain in joints and improves the mobility and health of the joint tissue.
11. Spirulina Assists in Inflammatory Bowel Diseases
Inflammatory bowel diseases (IBDs) like ulcerative colitis and Crohn's disease occur when the stomach and intestinal mucosal membranes get damaged or eroded.
This leads to inflammation of the gastrointestinal tract and can cause diarrhoea, abdominal pain, stomach ulcers, intestinal damage and in severe cases, stomach cancer.
With strong anti-inflammatory and anti-oxidant properties, Spirulina can inhibit various inflammatory markers, increase antioxidant enzymes and protect the mucosal membranes of the stomach and intestine from damage.
In cases of colitis, Spirulina has been shown to decrease inflammation of the mucosa and submucosa, abscess formation and tissue injury. 
Patients with IBD have been reported to have low Selenium levels in their bodies.
As Selenium helps in modulating immune responses, deficiency of Selenium can worsen the condition of such people or prolong the recovery period.
It has been shown that Selenium-enriched Spirulina or Phycocyanin can protect against body weight loss, bloody diarrhoea and colon damage caused by inflammation.
What does this Mean? By reducing inflammation, Spirulina protects the mucosal membranes of the gastrointestinal tract from damage and formation of ulcers in IBD cases.
12. Spirulina is a Potent Antioxidant
Antioxidants help in fighting off the toxins from the body. Metabolic processes in the body generate a number of waste products in the form of free radicals and reactive oxygen species (ROS).
These are toxic to the human body and thus, need to be neutralised by antioxidants.
When these toxins increase in number due to inflammation, infections, and injuries, they lead to the formation of oxidative stress.
This, if not controlled can cause further damage to body cells and organs and cause diseases. Thus, more antioxidants are required to fight them off.
There are many natural foods full of antioxidants which can improve the antioxidant ability of the body and prevent diseases arising from oxidative stress.
Spirulina is one such algal food with excellent antioxidative properties. 
Numerous studies, reporting the antioxidant effects of Spirulina, state that Spirulina activates many cellular antioxidant enzymes in the body and inhibits processes like oxidation which lead to the generation of free radicals.
It can scavenge the free radicals and neutralise them, thereby preventing oxidative stress and DNA damage.
What does this Mean? Spirulina can remove toxins and improve the antioxidant status of the body. It can prevent diseases occurring due to oxidative stress.
13. Spirulina Protects Against Toxicity
Spirulina, due to its excellent antioxidant effects can prevent and reverse the toxic effects of radiation, insecticides, heavy metals, chemicals, and drugs.
Heavy metal, insecticide and chemical toxicity usually occur by consumption of contaminated food and water, smoking or pollution.
On the other hand, toxicity due to radiation or drugs is often the side effect of a treatment measure for a health condition.
Toxicity caused by these agents can damage several body organs including liver, heart, kidney and testicles.
It also protects from:
- Cardiotoxicity caused by the antibiotic Tilmicosin 
- Kidney toxicity caused by the antibiotic Vancomycin 
- Kidney toxicity caused by chemotherapeutic drug Cisplatin  
- Kidney toxicity caused by Chromium and sodium fluoride  
- Liver and renal toxicity caused by the insecticide Deltamethrin 
- Liver and renal toxicity induced by diclofenac  Liver toxicity caused by Mercury chloride 
- Teratogenicity (disturbance in the embryonic development) caused by Cadmium 
- Thyroid dysfunction and neurological impairment in offspring caused by fluoride exposure 
- Testicular damage and sperm abnormality caused by Cadmium and Arsenite  
- Toxicity caused by Radiotherapy treatment of cancer 
What does this Mean? Spirulina can protect against the toxic effects and poisoning caused by many heavy metals, drugs, chemicals, insecticides and radiation.
14. Spirulina Promotes Liver Health
The liver plays diverse roles in our body. It assists in metabolic, storage and detoxification processes.
Liver disease or damage to liver cells can hamper these processes and affect health adversely.
Studies have shown that Spirulina can improve the levels of liver functioning enzymes which suggests that it can enhance liver function and metabolism.
Spirulina helps in the following liver conditions:
Non-alcoholic Fatty Liver Disease
Non-Alcoholic fatty liver disease occurs due to excessive deposition of fats in the liver, which is not caused by alcohol use.
Instead, it happens due to the consumption of a high-fat diet, increased lipid levels, diabetes or obesity.
It can cause inflammation in the liver and damage liver cells leading to liver cirrhosis or fibrosis.
In one such study conducted on 15 adults with Non-Alcoholic Fatty Liver Disease, Spirulina supplementation of 6g per day for six months was able to decrease triglycerides, total cholesterol, LDL-cholesterol, body weight and the levels of specific liver function enzymes.
It improved the overall metabolic health and quality of life of individuals with NAFLD. 
Spirulina has chemopreventive effects due to which it can prevent liver toxicity and cancer.
The protein C-phycocyanin from Spirulina can suppress the production of reactive oxygen species and inflammatory mediators that are responsible for inducing carcinogenesis.
Spirulina has hepatoprotective properties. With its antioxidant effects, Spirulina can prevent toxicity caused to the liver by several drugs (diclofenac , methotrexate , rifampicin, isoniazid ), insecticide (deltamethrin ), chemicals (calcium tetrachloride ) and heavy metals (lead  ). 
Hepatitis C Infection
Spirulina is a robust anti-viral agent which can inhibit the Hepatitis C virus and protect the liver from infection. In a study, 66 patients with Hepatitis C infection were treated with Spirulina.
After six months of treatment, Spirulina was able to completely end virological activity in some individuals while in some others, it decreases the viral load considerably.
Thus, it has the potential for therapeutic application in Hepatitis C patients. 
What does this Mean? Spirulina helps in various liver disorders including fatty liver disease, liver cirrhosis, hepatitis C infect and hepatotoxicity, thereby promoting liver health.
15. Spirulina Boosts the Immune System
Our immune system protects us from a number of infections, pathogens, and diseases. Thus, it is imperative to have good immunity.
Various natural substances have been known to boost our immune responses and provide protection against deadly pathogens. Spirulina is one of them. 
The antioxidants β-carotene and ascorbic acid in Spirulina increase the production of several immune cells and components like cytokines, natural killer (NK) cells, interferons, and antibodies.   
Ann extract of Spirulina containing Spirulina polysaccharides called Immulina has been developed that can enhance several immunological functions like activation of Natural Killer cells and the cells of the innate immune system to increase the production of antibodies, B-cells, T-cells, and interferon-gamma (IFN-γ).    
Spirulina being an immunostimulant, can serve as an excellent nutritional supplement for persons with compromised immunity like elderly or people suffering from a disease like HIV, cancer, and infections. 
A study was conducted on 40 older individuals who did not have any history of major chronic diseases.
They were given Spirulina supplementation for three months, and after the end of the study, increased hemoglobin concentrations and white blood cell count were observed.
This proves the potential of Spirulina in treating immunosenescence. 
In another study conducted on HIV patients, supplementation with Spirulina was found to improve the immune response by elevating levels of immune cells and reducing the viral load after six months of treatment. 
What does this Mean? Spirulina boosts the synthesis of various immune cells and components and prevents diseases and infections.
16. Spirulina is Beneficial for Individuals with Allergic Rhinitis
Allergic rhinitis or hay fever is a respiratory disease which occurs when the immune system overreacts to certain allergens present in the air.
This causes inflammation in the nose resulting in sneezing, coughing, eczema, runny nose or itchy and watery eyes.
Patients treated with conventional drugs often face the risk of side effects. Thus natural remedies are being explored.
In studies conducted on allergic individuals, Spirulina supplementation was able to modulate the immune response and decrease the levels of interleukins, which cause inflammation in the nose to occur.
What does this Mean? Spirulina reduces inflammation of nasal pathway and helps in relieving many symptoms in individuals with allergic rhinitis.
17. Spirulina Contributes to Prevention and Treatment of Cancers
Cancer occurs due to the uncontrolled and abnormal division of body cells, which then leads to the formation of tumours.
Inflammation and oxidative stress are known to induce tumorigenesis.
They can cause cellular damage and DNA injury. This can bring about alterations in DNA and result in the development of cancerous cells.
The treatment is done using several drugs and chemotherapy that have serious side effects.
Natural anti-cancer agents not only prevent cancer but can also provide safer treatment measures.
The microalgae Spirulina, its peptides, and the active ingredient C-phycocyanin are have been shown to possess potent anti-cancer propensities.
They have anti-inflammatory and antioxidant properties that can inhibit various inflammatory mediators, remove toxins, lower the oxidative stress, prevent the proliferation of cancerous cells and identify and kill cancerous cells without damaging the healthy body cells.    
The chemopreventive effects of Spirulina have been widely studied.
Spirulina has been found to show anti-cancer activity in various types of cancers namely- prostate cancer , pancreatic cancer  , breast cancer , skin cancer , ovarian cancer , colorectal cancer , stomach cancer , colon cancer  , oral cancer , liver cancer  , vulvar cancer , lung cancer   and leukaemia.
Recent research has shown that immunotherapy can assist in the treatment of cancer. Boosting the immune response could stimulate the immune cells to identify and kill cancerous cells.
We have mentioned how Spirulina acts as an excellent immunostimulant (See Section 18). Polysaccharides from Spirulina can activate the production of Interferon-gamma (IFN-γ) cells, which further inhibit tumour formation.
Thus, it has the potential to be used in cancer immunotherapy. 
Spirulina has also been found to protect against toxicity caused by cancer treatments like radiation, chemotherapy, and drugs.
What does this Mean? With its excellent anti-inflammatory, antioxidant and immune-boosting properties, Spirulina prevents cellular damage, toxicity and tumour formation. Its anti-cancer activity has been studied in many types of cancers. It also protects against the toxic effects of chemotherapeutic treatments.
(Read more 5 Benefits of Spirulina in cancer)
18. Spirulina aids in Oral Submucous Fibrosis
Oral submucous fibrosis causes the mucosal membranes of the oral cavity to get inflamed.
It is caused usually by tobacco and betel nut chewing and if left untreated, can cause oral cancer.
Symptoms include ulcers and pigmentation in oral mucosa, pain, stiffness, burning sensation with difficulty in eating and opening the mouth.
Studies report that Spirulina can ease several symptoms of this disease like improvements in mouth opening, burning sensation, ulcer formation, and erosions.
One study even stated that when compared to aloe vera, Spirulina brings about more significant changes in the subjects.
What does this Mean? Spirulina can assist in the conventional treatment of oral submucous fibrosis by improving mouth opening, burning sensation and reducing the formation of ulcers and erosions.
19. Spirulina Keeps in Check Skin Disorders
With immune-boosting properties, Spirulina promotes early wound healing and wound closure.
Skin cream incorporated with Spirulina extract has shown promising results in this regard, with the potential to be used in biomedical and cosmeceutical industries. 
The protein C-phycocyanin from Spirulina shows anti-melanogenic effect. This means it could decrease the production of melanin in skin cells, which otherwise can cause hyperpigmentation and skin conditions like Melasma. 
Prolonged or excessive exposure to the Ultraviolet (UV) rays from the sun can cause skin damage, skin ageing, pigmentation, and cancer.
Extracts from Spirulina have been shown to protect the skin from DNA damage, collagen destruction and skin ageing caused by harmful UV-B rays and preserve cell viability. 
To protect the skin from harmful effects of UV rays, the body induces inflammatory response which leads to the production of reactive oxygen species. This can further lead to tumour development and skin cancer.
Pretreatment with Spirulina with its anti-inflammatory, anti-oxidant and anti-tumour effects decreases the production of toxins and prevents tumour formation. 
What does this Mean? Spirulina can contribute to the maintenance of a healthy skin by fastening wound healing and protecting from hyperpigmentation, UV-induced damage and skin cancer.
20. Spirulina Delays Ageing and Age-Related Conditions
Aging or senescence weakens the body and its organ systems. It affects the overall health and well-being of an individual.
Almost all the major bodily processes and functions like immunity, nutrition, digestion, cognition, and skin health are affected.
Spirulina has been identified as an excellent dietary supplement for the elderly and prevention of ageing. This is because of the following reasons:
- It is incredibly nutritional and can help overcome nutritional deficiencies
- It boosts immunity and protects from infections and diseases like cancer 
- Promotes skin health, wound healing and prevents the skin from UV damage 
- Protect against age-related neurodegenerative disorders 
- Improves memory and cognition  
- Enhances hearing and auditory response and protects against oxidative stress-induced hearing loss, tinnitus and cochlear damage  
- Improves lipid profiles and antioxidant status 
What does this Mean? Spirulina can delay the ageing process and age-related disorders by improving the nutritional status, immune response, skin health, neurological health, memory, hearing capacity and metabolic profile.
21. Spirulina Protects Against Microbial Infections
Microbes including bacteria, fungi and virus cause several deadly diseases and infections in humans. Spirulina shows microbicidal activity against a wide variety of bacterial, fungal and viral strains:
Spirulina inhibits the growth of several Gram-positive (Staphylococcus aureus, Bacillus subtilis, Bacillus pumulis) and Gram-negative (E. coli, Pseudomonas aeruginosa, Proteus vulgaris) bacteria.
These bacteria are known to infections of the skin, gastrointestinal, respiratory and urinary tracts.
It can also change the concentration of several microbes present in the gut like those of the Lactobacillus, Bifidobacterium and Clostridium species.
Change in the gut microbiota composition by Spirulina can prevent the occurrence of various gastrointestinal and metabolic diseases. 
Viruses are the most difficult microbes to treat. Spirulina is one natural food which shows anti-viral activity against several viruses.
The polysaccharide Calcium-Spirulan in Spirulina inhibits several enveloped viruses which are usually hard to treat due to their protective envelopes.
It targets all the major processes in a virus life and inhibits both, the absorption or penetration in the host body, and replication inside the host body after penetration. 
The dominant viral strains inhibited by Spirulina include Herpes Simplex Virus type 1, HIV-1, Influenza A virus, mumps virus, measles virus, hepatitis C virus, Epstein-Barr virus, enterovirus-71, human cytomegalovirus and foot, and mouth disease virus.     
It aids extensively in following viral infections:
It causes the most common type of respiratory infection and flu. Treatment with vaccines is difficult due to the emergence of resistant strains.
Scientists have found that extracts from Spirulina can inhibit viral plaque formation, even by resistant strains of influenza viruses. 
Spirulina can further reduce the lethal effects and lung inflammation caused by the virus, by suppressing the activation of nuclear factor κ-B, which brings about inflammation. 
Immulina, a commercial extract of Spirulina can activate the innate immune responses to protect against infections from Influenza A (H1N1) virus. 
Thus, it has been identified as a safe and effective therapeutic agent to manage influenza outbreaks.
Herpes Simplex virus-1
Calcium Spirulan inhibits the attachment and penetration of HSV-1, HSV-2 and human herpesvirus eight into the host cells.
Human Immunodeficiency Virus (HIV)
This virus is responsible for causing one of the deadliest diseases of our times, AIDS. It weakens the immune system and makes the body susceptible to infections and diseases.
Spirulina shows antiretroviral activity by inhibiting the replication of the HIV-1 virus. 
It has been shown that regular consumption of Spirulina in diet can not only prevent viral infection but also decrease the viral load in infected individuals. 
It can improve insulin sensitivity caused by the use of antiretroviral drugs. 
What does this Mean? Spirulina can protect against a wide range of bacterial and fungal infections. It is also quite effective against various viruses including HIV, Herpes Simplex, hepatitis C and measles virus.
(Read more 5 Benefits of Spirulina in Herpes Simplex)
22. Spirulina can Prevent Several Neurodegenerative Disorders
The primary cause of neurodegenerative diseases is inflammation and oxidative stress in the brain cells.
Neuroinflammation causes toxicity to build up in the brain which then damages and injures the neurons and others types of brain cells.
Spirulina supplementation has been shown to reverse and prevent these effects due to its anti-inflammatory and antioxidant nature.
Spirulina has neuroprotective effects and helps in the following neurological conditions:
Neurotoxicity: Spirulina decreases the production of reactive oxygen species and development of oxidative stress in the brain.
Parkinson’s disease: The major cause of this condition is inflammation, imbalance of antioxidant enzymes and reduced dopamine levels in the brain.
Memory loss: Spirulina increases the levels of antioxidants and decreases the deposition of Amyloid-β proteins in the brain, which otherwise can damage cells of the hippocampus region and result in cognitive dysfunction.
Stroke: Spirulina improves blood pressure levels, vascular health, and lipid profile. It also prevents blood clot formation in the arteries. Thus, it protects the brain from the risk of stroke and cerebral ischemia. 
What does this Mean? Spirulina prevents neuroinflammation and neurotoxicity and thus, can prevent memory loss, stroke, Parkinson’s and Alzheimer’s diseases.
23. Spirulina Can Prevent some eye Diseases
Spirulina benefits in the following eye disorders:
This condition occurs due to the growth of new blood vessels in the corneal tissue which negatively affects vision transparency and acuity.
Topical application of polysaccharides derived from Spirulina can reduce inflammation and various factors and enzymes responsible for the formation of blood vessels.
They also inhibit proliferation, migration and tube formation in the eye tissue. Thus, they have a therapeutic application in corneal diseases which include neovascularisation and inflammation. 
Cataract and Macular Degeneration
Deficiency of a pigment called zeaxanthin in human eyes can cause diseases like cataract and age-related macular degeneration.
The algal food Spirulina has a high zeaxanthin content.
Thus, a study was conducted on fourteen healthy individuals, who were given 4-5g Spirulina daily for 45 days.
It provided them with about 2.6-3.7 mg zeaxanthin. After the study period, it was found that Spirulina supplementation increased the concentrations of the pigment in the body significantly.
It was concluded that Spirulina contains a highly bioavailable form of zeaxanthin and thus, can be used as a dietary supplement to prevent cataract and macular degeneration. 
What does this Mean? Due to its anti-inflammatory effect and high levels of zeaxanthin, Spirulina can prevent corneal neovascularization, cataract and macular degeneration.
24. Spirulina Benefits in Chronic Obstructive Pulmonary Disease
The chronic obstructive pulmonary disease is characterised by persistent breathing problems caused by disrupted airflow in the lungs. Symptoms include severe coughing, shortness of breath and sputum production.
Tobacco smoke is the main culprit which causes toxicity and oxidative stress to develop.
The disease is usually is accompanied by several other health conditions like diabetes, heart ailments, lung cancer, and microbial infections. 
In a study, the effects of Spirulina were examined in 30 individuals with chronic obstructive lung disease.
Results were studied after 30 days and 60 days of treatment which revealed that Spirulina could decrease levels of cholesterol and several toxins.
It also increases the concentration of antioxidants like vitamin C and glutathione. 
It has also been found that Spirulina, taken along with carvedilol can prevent lung inflammation and other pathological conditions that arise from smoking and nicotine intake and reduce the risk COPD. 
What does this Mean? Spirulina improves the lipid profile and antioxidant status in Patients with the Chronic Obstructive Pulmonary Disease.
25. Spirulina can Improve male and Female Fertility
Diabetes and oxidative stress are two of the many factors which affect female fertility.
Oxidative stress can deteriorate oocyte quality and reduce the reproductive ability in females. We have already seen that Spirulina is a potent antioxidant that can ameliorate oxidative stress.
Studies have found that the protein C-phycocyanin from Spirulina can decrease the formation of toxins, reactive oxygen species and oxidative stress in ovaries.
Thus, it can prevent oocyte fragmentation and restore impaired reproductive capability.
Spirulina can also increase reproductive performance, gestation length, fertility rate and survival rate of the fetus. 
Toxicity caused by heavy metals like arsenic and cadmium from contaminated water, soil and smoking can negatively affect testicular tissues.
It can decrease concentrations of zinc, antioxidants and male hormones. It can also further reduce sperm count and motility.
Spirulina, being an excellent antioxidant can prevent the development of toxicity in the male reproductive organs.
Studies have shown that Spirulina can attenuate the development of oxidative stress, testicular damage and sperm abnormalities caused by arsenic and cadmium intoxication.
However, these are preclinical studies, and further research is required to confirm these effects in humans.
What does this Mean? Spirulina can prevent oxidative stress in both male and female organs and improve reproductive performance.
26. Spirulina can Enhance Exercise Performance
Use of Spirulina among athletes and trainers is increasing, as it is believed to improve endurance, exercise performance and reduce fatigue.
There are some studies which prove this fact. 
A study conducted on nine trained males, who were given Spirulina supplementation for four weeks revealed that Spirulina supplementation has ergogenic and antioxidant effects.
It increased the antioxidant capacity and fat oxidation while decreasing fatigue levels. A significant increase in overall exercise performance was observed. 
International Journal of Food Sciences and Nutrition reports another study where 3g per day intake of Spirulina improved exercise output, performance and physical and mental fatigue in men. 
What does this Mean? Spirulina can benefits trainers, bodybuilders and athletes by decreasing fatigue and increasing exercise performance.
27. Spirulina can Prevent Exercise-Induced Muscle Damage
Rigorous or long-term exercising can cause inflammation damage to muscle cells.
Studies have shown that Spirulina can prevent muscular damage and extend the time of fatigue and exhaustion. 
Due to its anti-inflammatory effects, it suppresses inflammation and its mediators like prostaglandins and interleukins. Thus, it can improve muscle function and prevent injury. 
What does this Mean? Spirulina has protective effects against muscular damage caused by exercise.
Safety of Spirulina Consumption
- The United States Pharmacopeial Convention, which reviews the safety of many dietary supplements and their ingredients, has given Spirulina Class A safety rating and approved it as a dietary ingredient, after considering the various human trials and animal studies conducted on in this algal food. 
- Consumption of Phycocyanin, extracted from Spirulina, has also been classified as safe at a dosage of ~1g per day by the US Food and Drug Administration. 
- Many studies have ascertained the safety and tolerability of Spirulina and reported that it does not cause any toxicity or liver damage.   
Dosage of Spirulina
- There is no particular dosage of Spirulina in a health condition. One should consult with a medical practitioner for appropriate dosage amount and duration, especially if on medications like immunosuppressants, antihypertensive and lipid-lowering drugs. 
- Spirulina can be taken as a dietary supplement in the form powder, pills, tablets or flakes, as it is available commercially. Taking 4-5 tablets of 500 mg each per day is considered a standard dose. 
- A heaping teaspoon of about 15 g Spirulina contains about 100 mg of phycocyanobilin. Thus, two heaping teaspoons daily can be taken to improve antioxidant status. 
- Spirulina powder can be incorporated into soups, smoothies, soy milk, fruit juices, yogurt, wheat flour, cornflour, ice cream, snacks, baby food formulas, cereals and dough used for preparing bread, biscuits, and pasta. This will facilitate the intake and acceptability of Spirulina which otherwise is difficult to consume for some due to its taste, odour or appearance.   
Precautions to be taken with Spirulina
- One should consult healthcare professional before starting to take Spirulina, especially if on medications, as Spirulina can have adverse drug interactions.
- The water in which Spirulina is grown determines its quality and purity. Consumption of Spirulina grown in contaminated waters can result in toxicity and liver damage.
- It is imperative that one takes branded and high-quality supplements of Spirulina. Contaminated supplements may contain microcystins, arsenic, lead, cadmium and other toxins which may cause more harm than benefit.     
- Spirulina is known to boost the immune system. Thus, it is not advisable for use by persons with autoimmune diseases like rheumatoid arthritis, multiple sclerosis, and lupus, as it could further stimulate the overactive immune response. 
- Spirulina contains phenylalanine and is thus also not recommended for individuals with phenylketonuria as they are unable to metabolise this amino acid.
- Children, pregnant and breastfeeding women should consult with a doctor before taking Spirulina. 
- Spirulina can sometimes cause gastric problems, insomnia and allergic reactions like skin rashes, blisters, anaphylaxis in some individuals.     It can also be risky for people with seafood allergies if grown in salty waters.
Spirulina has the potential to be used as a nutritional and therapeutic dietary supplement due to its anti-inflammatory, anti-oxidant, anti-cancer, anti-diabetic, immune-boosting, blood pressure-regulating and lipid-lowering properties.
It can benefit in many inflammatory conditions like arthritis, allergic rhinitis, and inflammatory bowel disease.
It can help in the treatment and prevention of metabolic syndrome, diabetes, obesity, cancer, cardiovascular ailments, microbial infection, liver abnormalities, skin problems, eye disorders, neurodegenerative diseases, and age-related conditions.
It further assists in male and female fertility, oral submucous fibrosis, chronic pulmonary obstructive disease and muscle damage caused by exercise. Spirulina has something in store for people of all age groups and health conditions.
If taken with precautions, it is most likely to provide you with improved health and well-being.