Stevia is a popular, calorie-free sweetener derived from the leaves of the Stevia rebaudiana plant, which is native to South America. Its rise in popularity has led many people to question its safety, particularly concerning adverse reactions. This article explores whether a person can be allergic to Stevia, detailing the differences between a true allergic reaction and other sensitivities.
Understanding Stevia: Source and Processing
Stevia is a plant that belongs to the Asteraceae family, which also includes common plants like daisies and ragweed. The sweet taste comes from naturally occurring compounds in the leaf called steviol glycosides, such as Rebaudioside A (Reb A) and stevioside.
The type of Stevia found in most commercial products is a highly refined extract of these glycosides, not the whole leaf. This refinement isolates the sweet compounds while removing most plant proteins that could potentially trigger an allergic reaction. The U.S. Food and Drug Administration (FDA) has granted a “Generally Recognized As Safe” (GRAS) status to these highly purified steviol glycosides. However, the FDA has not approved the use of the whole Stevia leaf or crude extracts, citing a lack of safety data.
Allergic Reactions vs. Non-Allergic Sensitivities
When a person reacts to Stevia, it is important to distinguish between a true allergy and a non-allergic sensitivity. A true allergy is an immune system response involving the production of Immunoglobulin E (IgE) antibodies against a specific protein. These IgE-mediated reactions are typically rapid and can be severe. However, they are extremely rare with highly refined Stevia products due to the removal of most proteins during processing.
More common are non-allergic sensitivities, which do not involve the immune system but often result in uncomfortable physical symptoms. These reactions are frequently linked to the other ingredients mixed with the steviol glycosides in commercial blends. Many Stevia products use bulking agents, such as sugar alcohols like erythritol or dextrose, which can cause digestive upset. Therefore, a reaction to a Stevia-based product may actually be a sensitivity to one of its additives rather than the Stevia extract itself.
Recognizing Symptoms and Identifying Risk Factors
A true, IgE-mediated allergic reaction to Stevia would manifest with classic symptoms of hypersensitivity. These can include hives, itching, or swelling of the mouth, tongue, or throat, known as angioedema. In rare, severe cases, an allergy could lead to difficulty breathing, wheezing, or a sudden drop in blood pressure, which are signs of anaphylaxis.
Symptoms of a more common non-allergic sensitivity are usually concentrated in the digestive system. These may include gas, bloating, abdominal discomfort, or nausea, often attributable to the sugar alcohols used as fillers. If a person suspects a true allergy, they should consult an allergist who can perform a skin prick test or a blood test to confirm IgE antibody levels, though such testing for Stevia is not routine.
The primary risk factor for an allergic reaction to Stevia is a pre-existing allergy to other plants in the Asteraceae family. This grouping includes ragweed, chrysanthemums, marigolds, and daisies, and a sensitivity to one may result in cross-reactivity. Individuals with a ragweed allergy may have a higher potential for a reaction, particularly if consuming less refined or crude Stevia extracts. Because of the extensive purification, the risk of cross-reaction to the highly refined steviol glycosides is considered low.