Stevia - Sweetleaf

Common Names: Stevia, Sweetleaf, Sugarleaf, Honey leaves, Sweet herb of Paraguay, Stevia rebaudiana, Stevia rebaudian, Stevia sugarleaf, Stevia plant, Stevia sweetener, Global: Stevia, English: Sweetleaf, Latin: Stevia rebaudiana, Origin: Paraguay

Latin Name: Stevia rebaudiana

Origin: Asia, Europe, South America

Short Introduction

After a lengthy approval process, Stevia is now readily available in herbal shops, health food stores, and pharmacies. It can be purchased as a powdered extract, in capsules, or even as a live plant. Stevia is not well-suited to indoor cultivation; it prefers to be grown outside in a sheltered spot with partial shade, protected from the wind. However, if you choose to grow Stevia indoors (especially in colder climates), the best location is an east-facing windowsill in a regular flower pot.

Stevia thrives in the temperate climate, needing no special greenhouse or garden. The more warmth and light the plant receives, the greater the concentration of its active compounds. Exposure to cold may kill the plant. With proper care, one plant can yield up to 0.5 kg of dried leaves. Stevia attracts pests and slugs, so plant care is essential. The leaves can be used dried, fresh, or even frozen.

Wild Stevia plants in mountainous regions produce fewer seeds and typically propagate more efficiently through vegetative means. Over the years, Stevia has undergone numerous experiments to enhance production efficiency in Canada and other western countries, but today, it is most widely cultivated in East Asia (especially China, Taiwan, Korea, Thailand, Malaysia), as well as in South America (Brazil, Colombia, Peru, Paraguay, Uruguay) and Israel. In Japan, Stevia has been grown since 1971, with annual harvests reaching 15,000 to 20,000 tons of dried leaves. In Europe, Germany and Bulgaria are major growers.

Stevia seeds require light to germinate, so they should not be buried in soil. The substrate should remain moist but not waterlogged, as excess moisture may rot the seeds. Germination occurs best at a constant air temperature of around 22–25°C (72–77°F). The ideal time to harvest Stevia is just before flowering; otherwise, the plant will automatically dry out and the leaves will shrivel.

The active compounds in Stevia are very stable at high temperatures and can be used in various beverages and baked goods. Stevia is ideal for sweetening teas, diet foods, desserts, and pastries. It helps eliminate bacteria that cause oral health problems and prevents tooth decay. Stevioside is 200–300 times sweeter than sugar, with zero calories, making it suitable for weight loss diets and especially for people with diabetes.

Detailed Description

One of the healthiest natural sweeteners used worldwide.

Botanical Information

Stevia is a perennial herb with roots suitable for overwintering, originating from the mountainous tropics of northern Paraguay. It grows to a height between 50 and 100 cm, with small, vibrant green, opposite, lance-shaped leaves. Its white flowers are grouped into delicate clusters (corymbs). Originally an annual plant, selective breeding has transformed Stevia into a commercial perennial, and it is now propagated vegetatively via cuttings, root cuttings, and runners.

Origin and Distribution

Stevia comes from the mountain plains of Paraguay, where the Guaraní people were the first to consume its leaves with mate as a sweetener and use it in traditional medicine for heartburn, diabetes, and as a mouthwash. Stevia spread across South America to Brazil, Colombia, Peru, and Uruguay, with further production in East Asian countries, especially China, Taiwan, Korea, Thailand, and Malaysia. In Europe, Germany and Bulgaria are leading producers, while Israel also grows Stevia.

Usage / Dosage

In the 1980s, early studies questioned Stevia's safety, with some suggesting that steviol and its derivatives could be mutagenic and increase cancer risk. However, these findings were later refuted due to flawed methodology and have been disproved. Modern animal studies, using improved methods, demonstrate that Stevia compounds help increase insulin sensitivity in peripheral tissues, likely by stimulating insulin receptor production and boosting insulin output in both healthy and diabetic animals, thereby potentially reducing symptoms of diabetes.

In 2006, the World Health Organization and national health authorities reviewed Stevia’s safety and toxicity profiles. The results indicate that Stevia's constituents are safe, beneficial for people with type 2 diabetes and hypertension, and not mutagenic or toxic. Long-term use records from Japan and South America, since the 1970s, show Stevia is used as part of anti-cancer treatment protocols.

Stevia owes its sweetness (up to 300 times sweeter than sugar) to several diterpene glycosides generally called steviosides. Important compounds include rebaudiosides C, D, and E, which are 1.0–1.5 times sweeter than stevioside itself, dulcoside, and steviolbioside. These glycosides are commonly used around the world to sweeten drinks and are present in powdered sweetener blends for confectionery, preserved foods, toothpaste, and chewing gum industries.

Stevioside does not raise blood sugar levels; it works to stabilize glucose both in the liver and peripheral tissues. Thus, Stevia is recognized as a non-caloric sweetener, ideal for diabetics, hypoglycemics, and individuals with metabolic syndrome. It supports pancreatic function and its compounds are gentle on peripheral tissues.

Some people benefit from Stevia’s potential to reduce tissue damage in those with hypertension, improve digestion, reduce dietary fat absorption, and enhance muscle mass. Stevia compounds are also involved in cellular repair metabolism, increasing energy levels, and stimulating mental activity.

Stevia demonstrates mild antibacterial and antiviral effects in laboratory settings. In traditional medicine, Stevia extract is used to relieve tooth pain and bleeding gums. Later dental studies found that native populations using Stevia rarely suffer from gum pain and bleeding. This is because certain oral bacteria associated with periodontitis, decay, and plaque are susceptible to Stevia’s antibacterial properties. Stevia can be used as a gargle or in mouthwash solutions.

Other traditional uses of Stevia include soothing heartburn. Its compounds reduce local pain, mildly decrease hydrochloric acid production in the stomach, calm the digestive system, and reduce intestinal gas formation.

Pure Stevia concentrate is used on insect bites, acne, eczema, and slow-healing wounds, helping to soothe and heal the skin. A gentle central stimulating effect may also help relieve persistent fatigue and chronic fatigue syndrome. Stevia compounds have also been shown to reduce cravings for tobacco and alcohol.

Active Compounds

Stevia’s clinically recognized active compounds are derivatives of steviol glycosides, namely steviosides. Key substances include rebaudioside C, D, E, stevioside, dulcoside, and steviolbioside. These are stable at heat, have a neutral pH, and do not ferment. With cyclamate and saccharin being identified as mildly carcinogenic, Stevia has gradually replaced them in Japan and now occupies 40% of their artificial sweetener market. In Japan, Stevia is also included in traditional nonalcoholic beverages, such as colas.

Traditional Dosage

As Stevia is up to 300 times sweeter than sugar, only a small amount is necessary for sweetening. It can be used to sweeten tea or pastries. One cup of granulated sugar can be replaced by 1 to 2 tablespoons of powdered Stevia leaves or 2 to 3 tablespoons of dried, crushed leaves.
The simplest way to use Stevia is to steep 2–3 chopped or crushed leaves with other fresh herbs in a teapot for about 15 minutes, then strain. For tablets, one 60 mg Stevia tablet is equivalent to one cube of beet sugar.