Medicinal Herb Uses Of Stevia

South American natives have been using the leaves of the stevia rebaudiana plant as a sweetener for centuries. More recently, scientists have begun studying the plant for its medicinal effects in vitro, on animals and in human trials. The results from these studies show that stevia has the potential to treat and help prevent several serious diseases such as high blood pressure and diabetes.

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" in 1997 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" in January 2004 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.

Hypertension

After previous animal studies showed that stevioside has an antihypertensive effect, researchers at Taipei Wan Fang Hospital created a double-blind placebo-controlled study to test this effect on human subjects. This study group consisted of Chinese hypertensive subjects with diastolic blood pressure between 95 and 110 mmHg, with 60 subjects given active treatment and 46 given a placebo treatment. Each subject took capsules containing either stevioside stevia (250 mg) or a placebo three times a day and were followed up at monthly intervals for a year. After three months, the systolic and diastolic blood pressure of the stevia group decreased significantly, with the effects persisting throughout the entire year of treatment.

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.