Spirulina's therapeutic uses
Spirulina, a type of blue-green algae, is often marketed for its potential therapeutic uses, including nutritional support and various health benefits. It is rich in protein, vitamins, minerals, and essential fatty acids, making it a nutritious supplement. Proposed benefits of spirulina include support for weight loss, immune function, liver protection, and cholesterol management, among others. Research has indicated that spirulina may have antioxidant and anti-inflammatory properties, potentially aiding in exercise performance and detoxification from heavy metals.
Despite these claims, scientific evidence remains limited and more studies are needed to confirm its effectiveness for many proposed uses. Safety concerns exist due to the potential for contamination with toxic substances, such as microcystins and heavy metals, which can occur if spirulina is sourced improperly. While some studies have suggested benefits for conditions like allergic rhinitis and type 2 diabetes, the overall safety and efficacy of spirulina, especially for vulnerable populations like children and pregnant women, have not been fully established. As with any supplement, it's important for individuals to consult healthcare professionals before incorporating spirulina into their regimen.
Spirulina's therapeutic uses
- DEFINITION: Natural plant product used to treat specific health conditions.
- PRINCIPAL PROPOSED USE: Nutritional support
- OTHER PROPOSED USES: Cancer prevention, fibromyalgia, hay fever, herpes, high cholesterol, hives, human immunodeficiency virus support, immune support, liver protection, weight loss, antioxidant, anti-inflammatory, blood sugar support, exercise support, oral health, heavy metal detoxification
Overview
The supplement known as spirulina consists of one or more members of a family of blue-green algae. The name was inspired by the spiral shapes in which these plants array themselves as they grow. Other blue-green algae products are also available on the market and are discussed in this article.
Spirulina grows in the wild in salty lakes in Mexico and in Africa. It reproduces quickly, and because the individual plants tend to stick together, it is easy to harvest. Records of the Spanish conquistadors suggest that the Aztecs used spirulina as a food source. Also, the Kanembu people of Central Africa harvested it from what is now called Lake Chad.
This plant contains high levels of various B vitamins, beta-carotene, other carotenoids, and minerals, including calcium, iron, magnesium, manganese, potassium, and zinc. It is also a source of gamma-linolenic acid (GLA). Spirulina is a rich source of protein (dried spirulina contains up to 70 percent protein by weight) but one would have to ingest many spirulina capsules to obtain a significant amount of protein this way. Spirulina also contains vitamin B12, a nutrient otherwise found almost exclusively in animal foods. However, the B12 in spirulina is not absorbable.
Double-blind, placebo-controlled trials proving spirulina is effective for various medical conditions exist. However, increased study is necessary. Further, significant safety concerns involve all forms of blue-green algae.
Requirements and Sources
People other than those living within 35 degrees of the equator or on the shores of alkaline lakes will have difficulty finding spirulina anywhere but in health food stores. Most such stores carry several brands of spirulina that has been dried and processed into powder or tablets.
Therapeutic Dosages
Researchers studying spirulina’s effects on health have used a variety of dosages, ranging from 1 to 8.4 grams (g) daily.
Therapeutic Uses
There is no question that spirulina is a nutritious food, but it is not inexpensive. Protein can be obtained much more easily and inexpensively from legumes, nuts, grains, and animal foods; iron from dark greens, prunes, and meat; and carotenes and vitamins from standard fruits and vegetables.
Spirulina might have other specific therapeutic uses beyond general nutritional support, but the evidence supporting these recommendations has been limited to a handful of double-blind, placebo-controlled trials. Manufacturers of spirulina supplements sometimes claim that the plant can reduce appetite and thereby help overweight individuals control their food intake. However, one small double-blind study of spirulina for weight loss failed to find a significant difference between spirulina and placebo treatment. One small double-blind trial did find evidence that a blue-green alga called Chlorella pyrenoidosa might be useful for fibromyalgia.
It is commonly stated that spirulina and related products can enhance immunity. However, most evidence supporting this statement is too weak to mean much; the one meaningful trial, a double-blind study of 124 healthy adults, failed to find that chlorella supplements enhanced the immune response to the influenza vaccine.
Evidence from animal studies, preliminary human trials, and one small double-blind, placebo-controlled study suggests that spirulina and other forms of algae might improve cholesterol profile. Very preliminary evidence hints that spirulina may help prevent cancer.
Test-tube and animal studies suggest that spirulina might have some activity against human immunodeficiency virus (HIV). Still, much more research needs to be done before it can be concluded that spirulina is helpful against HIV infection.
Highly preliminary evidence suggests that spirulina or other blue-green algae products may counter allergic reactions, such as hay fever and hives, help protect the liver from toxic chemicals, reduce blood pressure, and control symptoms of ulcerative colitis.
Despite widespread publicity regarding the use of spirulina in the treatment of attention deficit disorder, there is no evidence that spirulina is effective against the disorder.
Additional proposed therapeutic uses of spirulina include taking it for its antioxidant and anti-inflammatory properties, which may help protect against free radicals that cause chronic health conditions. Studies have indicated spirulina may help increase endurance and decrease muscle fatigue, benefiting exercise performance. Spirulina may help the body detoxify from heavy metals, such as arsenic and mercury. Finally, spirulina may benefit oral health by decreasing plaque and gingivitis. More scientific study is necessary to confirm spirulina's effectiveness for these uses.
Scientific Evidence
Although there are a number of double-blind, placebo-controlled trials of spirulina, increased scientific study remains necessary.
Fibromyalgia. Fibromyalgia is a common chronic condition, the main symptoms of which are specific tender points on various parts of the body, widespread musculoskeletal discomfort, morning stiffness, fatigue, and disturbed sleep. The cause of fibromyalgia is not known, and current treatments are far from completely satisfactory. A study suggests that the nutritious algae C. pyrenoidosa might be helpful. In this double-blind, placebo-controlled trial, thirty-seven people with fibromyalgia were given either placebo or chlorella supplements at a dose of 10 g daily. At the end of three months, the individuals were switched to the opposite group and treated for an additional three months. The results showed significant improvements in symptoms when participants used chlorella compared with placebo.
Weight loss. A double-blind, placebo-controlled trial investigated the possible weight-loss effects of spirulina. However, while individuals taking 8.4 g of spirulina daily lost weight, the difference between the spirulina and placebo groups was not statistically significant. Larger and longer studies are needed to establish whether spirulina is indeed an effective obesity treatment.
Throughout the twenty-first century, double-blind, placebo-controlled trials of spirulina for various health issues have increased. These studies found spirulina can benefit allergic rhinitis by reducing symptoms such as sneezing, itchy nose, and congestion. Studies also found spirulina beneficial for type 2 diabetes patients, as it improved blood sugar control among participants. Similar positive effects were found in studies of spirulina for exercise endurance and cholesterol management.
Safety Issues
Spirulina itself appears to be nontoxic. Studies in rats showed that high spirulina intake caused no weight reduction or toxicity symptoms in rats, nor did spirulina affect the rats’ ability to reproduce normally.
Nevertheless, there are areas of serious concern for consumers. Various forms of blue-green algae can be naturally contaminated with highly toxic substances called microcystins. Some states, such as Oregon, place strict limits on the concentration of microcystins allowed in blue-green algae products, but the same protections cannot be assumed to have been applied to all products on the market. Furthermore, the maximum safe intake of microcystins is not clear, and it is possible that toxic effects might build up when individuals use blue-green algae for a long time. Long-term use by children raises particular concerns, especially in light of the widely popularized, but unsubstantiated, belief that blue-green algae is useful for attention deficit disorder. Blue-green algae can also contain a highly toxic substance called anatoxin.
In addition, when spirulina is grown with the use of fermented animal waste fertilizers, contamination with dangerous bacteria can occur. There are also concerns that spirulina might concentrate radioactive ions found in its environment. Probably of most concern is spirulina’s ability to absorb and concentrate heavy metals such as lead and mercury if they are present in its environment.
One study of spirulina samples grown in several locations found them to contain unacceptably high levels of these toxic metals. However, a second study on this topic claimed that the first used an unreliable method of analyzing heavy-metal content and concluded that a person would have to eat more than 77 g daily of the most heavily contaminated spirulina to reach unsafe mercury and lead consumption levels. These researchers, however, went on to suggest that it is not prudent to eat more than 50 g of spirulina daily because the plant contains a high concentration of nucleic acids, substances related to DNA. When these are metabolized, they create uric acid, which could cause gout or kidney stones. This is of special concern to those who have already had uric acid stones or attacks of gout. The safety of the use of spirulina by pregnant and nursing women, young children, and individuals with kidney or liver disease has not been determined.
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