Stevia

This member of the Aster family has a long history of native use in Paraguay as a sweetener for teas and foods. It contains a substance known as stevioside that is 100 to 300 times sweeter than sugar, but provides no calories. In the early 1970s, a consortium of Japanese food manufacturers developed stevia extracts for use as a zero-calorie sugar substitute. Subsequently, stevia extracts became a common ingredient in Asian soft drinks, desserts, chewing gum, and many other food products. Extensive Japanese research has found stevia to be extremely safe. However, there have not been enough U.S. studies for the FDA to approve stevia as a sugar substitute. Without identifying it as such, stevia is nonetheless widely used by savvy manufacturers to sweeten commercial beverage teas and other products. Although stevia is best known as a sweetener, it may also help reduce blood pressure, according to one large double-blind trial.

Although some people have claimed that stevia can help regulate blood sugar, the evidence for such an effect is negligible. This dietary supplement is primarily useful as a sweetening agent. New evidence suggests that stevia may also be helpful for hypertension.

Hypertension A 1-year double-blind study of 106 individuals given stevia extract found evidence of a significant reduction in blood pressure beginning at 3 months. In the treated group, the average blood pressure at the beginning of the study was about 166/102. By the end of the study, this had fallen to 153/90. In contrast, no significant reductions were seen in the placebo group.

Stevia is sold as a powder to be added to foods as needed for appropriate sweetening effects. It tastes slightly bitter if placed directly in the mouth, but in liquids this is generally not noticeable, and most people find the taste delightfully unique. In the hypertension study mentioned above, stevia was given as a standardized extract supplying 250 mg of stevioside 3 times daily.

Neither animal tests nor the extensive Japanese experience with stevia have uncovered any significant adverse effects. However, safety in young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established.