Stevia is recognized globally as a superior natural sweetener and a significant medicinal plant, particularly valued for its potent sweetness without the caloric content of sugar. The following is a long explanation of Stevia rebaudiana (Bertoni) Bertoni, based on its established characteristics and use, including its relevance in the context of global medicinal plants.
Herb's Introduction
Stevia rebaudiana (Bertoni) Bertoni is a perennial herb belonging to the Asteraceae family (the daisy or sunflower family). It is commonly known as Stevia, Sweet Leaf, or Honey Herb. This plant is indigenous to the mountainous regions of Paraguay and Brazil, where the native Guaraní people have utilized it for centuries, referring to it as kaa he’ẽ (sweet herb). Historically, they used its leaves to sweeten local beverages, such as mate tea, and for various traditional medicinal purposes, including regulating blood glucose levels. The plant gained worldwide recognition after its primary sweetening compounds, the steviol glycosides, were isolated in the early 20th century. Today, Stevia is cultivated globally and is the foundation for virtually zero-calorie sweetener products that are up to 300 times sweeter than sucrose (table sugar), making it a cornerstone in the functional food and natural health industries.
Name in Different Countries
Due to its global cultivation and historical importance, Stevia rebaudiana has acquired numerous common names across different languages, reflecting its primary characteristic—sweetness. Language Name Meaning/Significance English Stevia, Sweet Leaf, Sweet Honey Leaf Direct reference to its intense sweet taste. Guarani caa êhê (or ka'a he'ẽ) "Sweet herb" or "Sweet grass," its original indigenous name. Sanskrit Madhu patra "Honey leaf." Thai หญ้าหวาน (ya wan) "Sweet grass." Persian شیرینبرگ (shirin-barg) "Sweet leaf." Japanese ステビア (sutēbia) Japanese phonetic rendering of Stevia. Chinese 甜叶菊 (tiányè jú) "Sweet leaf chrysanthemum" (referring to its family). Export to Sheets The plant is also known as Estèvia (Catalan), Stévie sladká (Czech), Honigkruid (Dutch), 스테비아 (Korean), and Cỏ ngọt (Vietnamese).
Terminology
The defining characteristics and biological actions of Stevia are intrinsically linked to the chemical compounds found within its leaves, collectively known as steviol glycosides (SG). Steviol Glycosides (SG): This is the chemical class of compounds responsible for the sweetness. The plant produces over 30 different steviol glycosides, all sharing a core molecule called Steviol (the aglycone). Stevioside: This is typically the most abundant steviol glycoside in the leaves, providing intense sweetness (around 200–300 times sweeter than sugar). Rebaudioside A (Reb A): Often considered the most desirable compound because it is generally the sweetest (up to 450 times sweeter) and possesses the least bitter aftertaste compared to stevioside. Non-Nutritive Sweetener: A common term used in nutritional science, meaning it provides intense sweetness with virtually no caloric contribution or nutritional value in a standard serving size. E960: The European Union classification number for purified steviol glycosides when used as a food additive.
Availability
While historically confined to South America, Stevia rebaudiana is now a commercial agricultural crop grown worldwide, primarily in sub-tropical and mildly tropical regions, but also in greenhouses in temperate climates due to its intolerance to frost. Global Cultivation: Major producers include Paraguay, Brazil, China (which quickly became the largest commercial exporter), Japan, Thailand, India, Vietnam, and Indonesia. Regional Context (Nepal): Stevia is considered a significant Medicinal and Aromatic Plant (MAP) globally. In the Himalayan region, including Nepal, its cultivation has been explored and established on an experimental and small-commercial basis, particularly in hilly areas with warm, moist, and sunny conditions, positioning it as a potentially valuable cash crop within Nepal’s growing MAPs sector. Commercial Forms: It is highly available globally as dried whole leaves, crude leaf powder, liquid extracts, refined white powder (pure Reb A/Stevioside), and tablets.
External Look
Stevia rebaudiana is a relatively compact and bushy plant that can be described as a small herbaceous perennial shrub. Size and Structure: It typically reaches a height of 30 to 75 centimeters (1 to 2.5 feet). Its stems are soft and highly branched, developing from a strong, shallow rootstock in frost-free environments. Leaves: The leaves are the primary source of the sweetening compounds. They are elongated, lanceolate, or oval-shaped, up to 8 cm long, and arranged oppositely along the stem. The leaves are typically bright to dark green and may have fine hairs on their surface, sometimes giving them a look similar to mint leaves. Flowers: The plant produces small, inconspicuous, and typically non-fragrant white or cream-colored flowers with light purple accents. These small flower heads (capitula) are grouped into terminal clusters. In commercial cultivation, the flowering tops are often trimmed, as the onset of flowering can reduce the sweetness content in the leaves. Fruit/Seeds: The fruit is a thin, ribbed, spindle-shaped achene (a small, dry fruit) equipped with a feather-like, hairy tuft (pappus), which aids in wind dispersal.
Healing Properties
Beyond its primary role as a sugar substitute, Stevia possesses several valuable medicinal properties attributed to its chemical composition, which includes steviol glycosides, diterpenoids, and polyphenols. Hypoglycemic Action: Stevia has a profound hypoglycemic effect, meaning it helps to lower and regulate blood sugar levels. Crucially, it has a glycemic index (GI) of zero and does not cause insulin spikes, making it an ideal remedy for early-onset diabetes and safe for managing blood glucose. Studies suggest it can even improve insulin sensitivity. Anti-hypertensive: The herb is known to help lower blood pressure levels, offering potential benefits for individuals with hypertension (high blood pressure). Antimicrobial and Anti-caries: Stevia exhibits antimicrobial activity. When used as a sweetener, it is anti-plaque and anti-caries (cavity-preventing) because the steviol glycosides are non-fermentable and do not feed the oral bacteria responsible for tooth decay, unlike regular sugar. Antioxidant Activity: Stevia leaves are rich in antioxidants, including high levels of phenolic compounds (like chlorogenic acid). These compounds help reduce oxidative stress and promote overall cellular health. Anti-inflammatory: Specific diterpenoids found in the leaves, such as manoyl oxide, have demonstrated anti-inflammatory and anti-parasitic actions.
Advantages
Stevia rebaudiana holds several compelling advantages over both traditional sugar and artificial sweeteners: Zero Calories and Carbs: It is virtually free of calories and carbohydrates, supporting weight-loss diets and providing a non-nutritive way to enjoy sweetness. Natural Origin: It is derived directly from a plant, appealing to consumers seeking whole, natural ingredients over synthetic artificial sweeteners. Suitable for Diabetics: Its complete lack of impact on blood glucose and insulin makes it a safe, effective, and recommended alternative for diabetics and hypoglycemics. High Stability: Stevia extracts are exceptionally heat-stable (stable up to 198°C), making it suitable for use in high-temperature applications like baking, cooking, and canning without losing its sweetening power or altering its chemical structure. Promotes Dental Health: It actively helps prevent tooth decay, contributing to better oral hygiene.
Uses
The uses of Stevia rebaudiana span from traditional herbal medicine to modern industrial food production. Sugar Substitute (Food and Beverage): This is its most widespread use, replacing sugar in coffee, tea, soft drinks, juices, chewing gum, candies, chocolates, yogurts, and baked goods. Purified extracts like Reb A are the industry standard for commercial products. Medicinal Sweetener: The dried leaf or crude powder is used to sweeten medicinal decoctions and herbal teas, particularly for diabetic or weight-conscious individuals who must avoid sugar or honey. Traditional Medicine: In its native regions, it is used traditionally as a remedy for diabetes, hypertension, and digestive issues, and sometimes applied externally to aid wound healing. Nutraceutical and Pharmaceutical: The purified glycosides and other compounds (like phenols) are incorporated into health supplements, mouthwashes, and health drinks for their antioxidant, antimicrobial, and blood-pressure-lowering effects.
Using way
Stevia can be consumed in various forms, depending on the desired intensity, purity, and application: Using Dried Leaves (Crude Form): This is the simplest and most traditional method. A few dried, crushed, or whole Stevia leaves can be directly added to a cup of hot water or herbal tea and allowed to steep. This method retains the maximum array of beneficial plant compounds but may introduce a slight herbal or licorice-like aftertaste. The dried leaf can also be ground into a homemade powder. Refined Stevia Powder: This form is highly purified and concentrated, consisting mostly of Stevioside or Reb A. It is used in precise quantities for baking and general sweetening. Due to its intense sweetness, conversion charts are necessary (e.g., approximately 1 teaspoon of refined powder can replace 1 cup of sugar). Stevia Liquid Extract (Fluid): This is a highly concentrated solution of steviol glycosides, often extracted using water or food-grade alcohol. A few drops are sufficient to sweeten a glass of liquid, making it a convenient and portable option for sweetening beverages. Tablets: Small, dissolvable tablets are used as a zero-calorie substitute for sugar cubes in coffee or tea, offering maximum convenience and portion control.
Conclusion
Stevia rebaudiana represents a remarkable fusion of traditional botanical knowledge and modern functional food science. As a natural, non-nutritive sweetener, it addresses critical global health challenges by offering a safe, highly potent alternative to sucrose for managing diabetes, obesity, and hypertension. Its array of additional healing properties, including antioxidant, antimicrobial, and dental protective effects, solidifies its position not merely as a sugar substitute but as a valuable medicinal plant. The increasing commercial cultivation of Stevia worldwide, including in key regions like Nepal, highlights its economic and health significance as a sustainable resource for promoting healthier dietary practices globally.
