What is Stevia? A Closer Look at the Sweetener
Stevia is a zero-calorie sweetener derived from the leaves of the Stevia rebaudiana plant, native to South America. The sweet components, called steviol glycosides, are extracted and purified to create the stevia sweeteners found in many food and beverage products. While crude stevia leaf and extracts are not approved for sale as sweeteners in the U.S., highly purified steviol glycosides (≥95%) have been approved by the U.S. Food and Drug Administration (FDA) and are considered "Generally Recognized as Safe" (GRAS).
Potential Side Effects of Stevia
When consumed in moderate quantities, highly purified stevia is generally considered safe for most people and rarely causes adverse side effects. However, some individuals may experience issues related to the product's formulation or pre-existing sensitivities.
Digestive Issues
One of the most frequently reported side effects is gastrointestinal discomfort. This is often caused not by the steviol glycosides themselves, but by added ingredients, such as sugar alcohols like erythritol, sorbitol, and xylitol. When consumed in large amounts, these sugar alcohols can cause symptoms such as:
- Bloating and gas
- Nausea and cramping
- Mild diarrhea
Allergic Reactions
Allergic reactions to stevia are extremely rare. The primary concern relates to cross-reactivity for individuals with allergies to plants in the Asteraceae family, which includes ragweed, daisies, and chrysanthemums. Highly purified stevia products, however, are processed to remove the proteins that trigger allergic responses, making the risk very low. Symptoms of a reaction might include itching in the mouth or throat, swelling, or hives.
Drug Interactions
Stevia's potential effects on blood sugar and blood pressure mean it can interact with certain medications. Individuals on the following medications should consult a doctor before using stevia consistently:
- Antidiabetic drugs: Since stevia may help lower blood sugar, combining it with diabetes medication could cause blood glucose levels to drop too low.
- Antihypertensive drugs: Stevia has blood pressure-lowering properties, which could enhance the effect of medications used to treat high blood pressure, leading to blood pressure that is too low.
- Lithium: Stevia has a diuretic effect, which could potentially affect how the body excretes lithium.
Comparison Table: Stevia vs. Sugar and Sugar Alcohols
| Feature | Stevia (Purified Extract) | Sugar (Sucrose) | Sugar Alcohols (e.g., Erythritol) |
|---|---|---|---|
| Calories | Zero | ~16 calories per tsp | Fewer than sugar |
| Glycemic Index | Zero (no impact on blood sugar) | High (can cause blood sugar spikes) | Low (less impact than sugar) |
| Aftertaste | Can have a slightly bitter or licorice-like taste | None (neutral) | Can have a cooling sensation |
| Digestive Impact | Often benign, but additives like sugar alcohols can cause issues | Generally none, unless consumed in excessive amounts | Can cause bloating, gas, and diarrhea in large quantities |
| Best Use | Drinks, baking (with adjustments), moderate everyday use | Baking, general sweetening (in moderation) | Confectionery, sugar-free gum, products for diabetics |
Unsafe Forms and Potential Concerns
It is important to differentiate between highly purified steviol glycosides and unrefined stevia products. The FDA does not recognize whole stevia leaves or crude extracts as safe for use in food, as there is insufficient safety data. Concerns have been raised about potential risks associated with these unpurified forms, though they are not approved for commercial food use. Some early studies on less-refined stevia products raised concerns about fertility and hormonal effects, but modern, large-scale studies on the high-purity extracts approved for sale have not found evidence to support these claims.
What the Experts Say: Regulatory Approvals
Worldwide regulatory bodies have affirmed the safety of highly purified stevia extracts. The Joint FAO/WHO Expert Committee on Food Additives (JECFA), the FDA, and the European Food Safety Authority (EFSA) have all established an Acceptable Daily Intake (ADI) level for steviol glycosides. This indicates that moderate, regular consumption is not linked to long-term health risks like toxicity, cancer, or organ damage.
Conclusion: The Bottom Line on Stevia Side Effects
In conclusion, highly purified stevia extract is a safe, zero-calorie sweetener for most people when consumed within established acceptable daily intake limits. The potential side effects commonly associated with stevia, such as digestive upset, are most often caused by added ingredients like sugar alcohols rather than the stevia extract itself. While allergic reactions are rare, individuals with allergies to related plants should exercise caution. Those with diabetes or blood pressure issues should consult a doctor due to possible drug interactions. For the average consumer looking to reduce sugar intake, purified stevia remains a viable and safe alternative.
For more detailed information on sweeteners, visit: FDA Guidance on Sweeteners
Considerations for Different Stevia Users
- For diabetics: While pure stevia does not affect blood sugar, it's crucial to check labels for additives like dextrose or maltodextrin that can impact glucose levels.
- For those with digestive sensitivity: Pay close attention to ingredients lists and consider a pure stevia extract without sugar alcohols to minimize bloating and gas.
- For pregnant or breastfeeding women: While purified stevia is generally considered safe, there is less definitive research. It is best to consult a healthcare provider for personalized advice.
By being an informed consumer and choosing highly purified products, most people can safely enjoy the benefits of stevia without experiencing negative side effects.
