Stevia Safety and the Acceptable Daily Intake (ADI)
Stevia, extracted from the Stevia rebaudiana plant, is a non-nutritive sweetener. It gets its sweetness from steviol glycosides. Globally, regulatory bodies have set an Acceptable Daily Intake (ADI) for high-purity stevia leaf extract (minimum 95% steviol glycosides). The ADI is 4 mg per kg of body weight per day, a level including a safety margin for lifetime use.
Calculating Your Stevia ADI
The ADI is based on steviol equivalents. For a 150-pound (70 kg) adult, the calculation is: $70\,kg \times 4\,mg/kg/day = 280\,mg$ of steviol equivalents daily. Consuming this amount from common sweeteners (approx. 21 mg steviol glycosides per packet) would require around 40 packets per day, far exceeding normal use.
Approved and Unapproved Forms of Stevia
Only highly purified steviol glycoside extracts have U.S. FDA Generally Recognized as Safe (GRAS) status.
Approved forms (GRAS status):
- High-Purity Steviol Glycoside Extracts: These are at least 95% pure (e.g., Reb A, Reb M) and safe for use.
Unapproved forms:
- Whole Stevia Leaves: Not FDA-approved for food due to insufficient toxicology data.
- Crude Stevia Extracts: Less refined extracts are also unapproved.
Comparison: Stevia vs. Other Sweeteners
| Feature | Stevia (Purified Extract) | Refined Sugar | Aspartame (Artificial Sweetener) |
|---|---|---|---|
| Source | Stevia plant leaves | Sugar cane or beet | Synthesized in a lab |
| Calories | Zero calories | ~16 calories per teaspoon | Minimal calories |
| Blood Sugar Impact | Does not raise blood glucose | Raises blood glucose significantly | Does not raise blood glucose |
| Aftertaste | Some may experience a slight bitter or licorice-like aftertaste | No aftertaste | Some describe a chemical aftertaste |
| Dental Health | Non-cariogenic (does not cause tooth decay) | Contributes to tooth decay | Non-cariogenic |
| Safety Status | GRAS (Generally Recognized as Safe) | Generally recognized as safe in moderation | FDA-approved for specific uses |
Potential Side Effects of Stevia
While pure stevia within the ADI is generally safe, mild side effects can occur.
- Some products with sugar alcohols may cause gastrointestinal issues.
- People with allergies to ragweed and related plants might be more sensitive.
- Stevia could affect blood sugar and pressure; monitoring is advised.
Stevia's Impact on Gut Health
Research shows that purified stevia has minimal impact on the gut microbiome. It doesn't appear to disrupt healthy gut bacteria like some artificial sweeteners.
Long-Term Safety and Conclusion
Health authorities like the FDA and JECFA support the long-term safety of high-purity steviol glycoside extracts within the ADI. Exceeding the ADI through typical use is unlikely. Raw and crude extracts aren't approved due to lack of safety data, but regulated purified products are considered safe.
Conclusion: Safe Stevia Consumption
High-purity stevia extract is generally safe within the ADI of 4 mg/kg/day. Choosing purified versions avoids potential side effects from additives. Consult a healthcare professional for health concerns. Purified stevia is a safe, well-tolerated sugar alternative. Further details on food additive safety are available from the {Link: FDA's Generally Recognized as Safe (GRAS) notice https://www.fda.gov/media/119340/download}.
