History
Ancient South American people used the leaves of the stevia plant to sweeten their cuisine, such as mate, a drink. Conquistadors found out about it when they invaded South America in the 1500s. Credit for the discovery of stevia is attributed to an Italian doctor, Dr. Moises Santiago Bertoni, though the plant had been used by Paraguay's indigenous population since early times. Tribespeople of the Guarani nation would pull off the leaves and simply chew them for sweetness, as well as use the leaves to sweeten their naturally bitter mate tea and make medicinal poultices. Settlers were introduced to stevia by Spanish researchers, and soon the substance was in daily use throughout the region (including nearby Brazil and Argentina). Beginning in 1971, Japan began using stevia as a regular food additive. Now, stevia makes up almost half the sweetening market.Stevia is grown in Asia and South America, in Israel and experimentally in Ontario. Within Asia it is grown in Thailand, Malaysia, Korea, China and Taiwan. In South America it is cultivated in Uruguay, Peru, Paraguay, Brazil and Columbia.
The plant from which stevia is extracted, with the scientific name of Stevia rebaudiana Bertoni, native to Paraguay. It has been cultivated there by the indigenous population (specifically, the Guarani tribe of the region between the Uruguay and lower Paraguay Rivers) since ancient times. The Guaranis call the plant 'Ka'a he'é in ne'e Guaraní (Kaa he-he, colloquially). The leaf of the stevia plant is also known by the names sweet leaf and sugarleaf.
The plant from which stevia is extracted isn't particularly showy. When full-grown, the plant develops into a large, bushy shrub. Its flowers are small, delicate and white, clustered on the ends of the stalks. Its green, non-descript leaves are the source of stevia's claim to fame. They contain a compound that has a delicious, refreshing taste that on average is about 300 times sweeter than cane sugar.
Stevia is a flowering herb. It has small, oblong leaves with hairs, and its flowers grow in bunches ranging from two to six together. The average width of a stevia plant is 2 feet, and the average height of a stevia plant is 2 to 3 feet depending on soil content. Of the all the species in the Stevia genus, Stevia rebaudiana is the sweetest. It also is difficult to grow from seed. Plants in the Stevia genus are native to South America and Central America. Species can be found in semi-arid, tropical and subtropical climates, and have been known to grow as far north as Texas, New Mexico and Arizona.
Benefits
The human body doesn't have the capability to metabolize stevia's sweet glycosides, so they pass right through the body without providing calories or adversely affecting levels of blood glucose. Of course, this makes stevia a boon for folks with diabetes, pre-diabetes, blood pressure issues or excess weight. Notably, this isn't the only benefit to stevia's nutritional index. Stevia's leaf and essential oil also contains vitamins C and A, fiber, potassium, protein, iron, phosphorus, calcium, sodium, magnesium, zinc, rutin and antioxidant flavonoids.The stevia plant's main uses are as a sugar and artificial sweetener replacement and dietary supplement. Extracts of stevia are made for culinary uses; though in high concentrations create an aftertaste that can be bitter. These extracts can be as high as 300 times sweeter than sugar.
In the medical practices of the Guarani tribes, stevia was used for a variety of ailments, including high uric acid levels, hypertension, heartburn and obesity.
Lowers Blood Sugar
Traditional medicine has long valued stevia in treating diabetes. The "Encyclopedia of Common Natural Ingredients used in Foods" says that at least one of the components of the stevia herb (a substance called stevioside) improves the action of insulin and glucose metabolism and helps control high blood sugar levels in type-2 diabetes.Lowers Blood Pressure
Citing multiple scientific studies, both the Preventive Medicine Research Institute report and Zhion Health, stevia acts like medications known as vasodilators, widening blood vessels to lower both systolic and diastolic blood pressure, without producing significant toxicity or side effects. However, stevia's safe use along with other blood pressure medications--as is true of all medically potent herbs--should only be attempted with regular monitoring and in consultation with a physician.Eliminates Fats and Sodium
Andreas Moritz, author of the "Timeless Secrets of Nutrition and Health" article on the Natural News website, writes that stevia's medicinal properties can be viewed as replacement therapy to displace sugar in dietary sweets and snack foods with a zero-calorie sweetener for diabetes or obesity treatment. This may reduce cravings, ingestion of high-calorie fats and high sodium snack foods. These savings also help lower blood pressure, blood sugar and possibly cholesterol and preservatives and other common fast food additives. However, satisfying a sweet tooth, even with stevia, may sabotage diets which would be better served by changing dietary tastes altogether.Antimicrobial
A study at Japan's Fukushima Medical University investigated stevia's effects on the anti-human rotavirus, or HRV, and found that the stevia helped to blockade the virus from attaching to cells. A separate Japanese study published in "The Journal of Microbiology, Immunology and Infection" showed that a fermented aqueous extract from stevia killed the food-borne pathogenic bacteria Escherichia coli without significantly harming the friendly intestinal bacteria, Bifidobacteria or Lactobacilli.Antioxidant
Indian scientists looked at the in vitro potential of ethanolic leaf extract from stevia as a natural antioxidant. The study, performed at Dr. H.S. Gour University, found that the stevia extract scavenged a superoxide anion, or toxic component of the immune system, that can lead to free radical damage, and inhibited other free radicals as well, including hydroxyl radical and nitric oxide. The results led the researchers to conclude that stevia has a significant potential for use as a natural antioxidant agent.Diabetes
A study in Denmark published in the journal "Metabolism" reported on research into the treatment on diabetics using stevioside, a component of the stevia plant. Patients were given a test meal supplemented with either 1 g of stevioside or 1 g of maize starch, and blood samples were drawn at 30 minutes before and for 240 minutes after ingestion of the test meal. Compared to the control/maize group, stevia reduced the glucose response curve by 18 percent and increased the insulinogenic index by approximately 40 percent. The study showed that stevia reduces postprandial blood glucose levels in type 2 diabetic patients with beneficial effects on glucose metabolism.Immunity
Immunomodulators are substances that don't boost immunity, but rather normalize it, and several research projects have tried to use this effect to develop an effective treatment for various immune system ailments. Scientists at the Indian Institute of Integrative Medicine looked at stevia as a potential immunomodulator, using different doses on treated mice versus a control group and found marked immune-protecting properties such as stimulating humoral and cellular immunity and white blood cell function.Theories/Speculation
A study was conducted in the late '60s by a Purdue University researcher (Professor Joseph Kuc) to determine the truth of rumors he'd heard about stevia's traditional use as a contraceptive. The rats in the study indeed showed that stevia had a contraceptive effect - but, notably, they were given an extremely high dose of stevia (an amount nearly impossible for a human to duplicate in one's diet) in a concentrate that entirely replaced their drinking water.Stevia can possibly help with high blood sugar, obesity and hypertension. Also, stevia has been found to reduce egg shell breakage in chicken eggs when it is added to chicken feed, thus suggesting stevia as an osteoporosis treatment.
Though it is consumed around the world, stevia has been banned for consumption in the United States by the FDA since the 1990s, unless labeled as a supplement. This means that when selling stevia, it cannot be legally called a sweetener. This ruling is controversial, as it contradicts the guidelines the FDA itself had set down: the generally recognized as safe (GRAS) designation.
Despite this ruling, in 2008 the FDA approved the products Truvia and PureVia, both of which are derived from the stevia plant, using the GRAS designation.
Extracts from the herb are up to 300 times sweeter than sugar, and today stevia has become popular around the world as a natural alternative to sugar. In America, it is marketed as a health supplement under the brands Rebiana, Truvia, and PureVia.
Compounds
Stevia's long-lasting sweet taste is due to two glycosides: stevioside and rebaudioside A. These compounds are intensely sweet, but are not converted into glucose within the body; they are also heat stable and acid stable. In addition, the World Health Organization has issued a statement that no carcinogenic substance can be found in either compound, making stevia a safer alternative to other sweeteners like saccharin.Clinical Use
Stevia has been used in Brazil and Paraguay for centuries as an addition to stomach-soothing medicinal teas. As it is relatively new to the American clinical scene, physicians are now testing stevia for its reputed ability to lower blood pressure and alleviate heart disease; recent research has found stevia to be useful in treating hypertension and obesity. In addition, scientists have found that eggshell breakage can be reduced significantly by adding stevia powder to chicken feed, suggesting that stevia expedites calcium formation.Glucose Substitute
For people with diabetes, hypoglycemia, or other metabolic conditions, stevia is a valuable substitute for sugar in an everyday diet. Steviosides pass through the body without being digested or metabolized, and thus stevia is an effective aid for the regulation of blood sugar. It also enhances glucose tolerance, making it even more attractive to diabetics.
Agricultural Use
In Japan and other Asian countries, stevia has been used for a variety of purposes for decades, and Japanese farmers have even begun manufacturing fertilizer from the stevia plant. Crops produced with this fertilizer are said to be fresher and better-tasting; they are also reputedly more nutritious. Stevia is said to dramatically increase the rate of fermentation without any unpleasant side effects, and thus the herb could have great potential for use in composting.Other Benefits
Stevia has many other health benefits. When used orally, in mouthwash, stevia has antibacterial qualities, and toothpaste manufacturers have begun to add stevia to their products. Stevia has the same antibacterial effect when used externally, in poultices and ointments: it is useful in the treatment of skin conditions such as eczema and acne, and it speeds the healing of wounds.Dangers
Stevia is typically used in small quantities to sweeten beverages, which poses no obvious harm to consumers. However, scientists worry that if stevia is used by global companies such as Coca-Cola or Pepsi, consumption may increase and potentially cause dangerous side effects. Both companies have developed their own stevia products, Truvia and PureVia, respectively.According to CSPI, European scientists have found that stevioside reduces sperm production and could cause infertility in males. In addition, the effect of stevia on the female reproductive system remains unresolved.
CSPI also reports that large amounts of stevioside consumption has been shown to interfere with the absorption of carbohydrates in animals. Moderate use (one to two times per day) is considered to be safe. More research on the effects of stevia is needed to determine long-term health effects.
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