Stevia has become a popular sugar substitute for many looking to reduce their calorie intake and manage conditions like diabetes. Derived from the leaves of the Stevia rebaudiana plant, its purified extracts are considered generally safe for consumption by the Food and Drug Administration (FDA). However, the safety of stevia is not universal, and several groups of people need to be cautious or avoid it altogether. The risks often stem from the sweetener's biological effects and interactions with other substances.
Medical Conditions and Drug Interactions
Certain medical conditions and medications can interact negatively with stevia, making its use potentially hazardous. It is critical for individuals with pre-existing health concerns to consult a healthcare professional before incorporating stevia into their diet.
People with Diabetes
While often marketed towards diabetics, stevia must be used with care. Pure stevia extract itself does not affect blood glucose levels significantly, but many commercial stevia blends contain additives that can. Dextrose and maltodextrin, common fillers, have high glycemic indexes and can cause blood sugar spikes. Furthermore, stevia has blood sugar-lowering effects, which can cause hypoglycemia (blood sugar dropping too low) when combined with diabetes medications. Close monitoring and medical supervision are necessary for people with diabetes using this sweetener.
Individuals with Low Blood Pressure
Stevia is known to have a blood pressure-lowering effect, which can be beneficial for those with hypertension. However, for individuals who already have low blood pressure (hypotension), consuming stevia could cause blood pressure to drop to unsafe levels, leading to symptoms like dizziness and fatigue. Those taking blood pressure medication should also be aware that stevia can amplify the drug's effects.
Patients on Lithium
Stevia acts as a diuretic, meaning it increases the rate at which the body expels water and electrolytes. For patients taking the medication Lithium, this diuretic effect can reduce how efficiently the body clears lithium, potentially causing a dangerous build-up of the drug. It is crucial to discuss stevia use with a healthcare provider if you are on Lithium.
Those with Kidney Concerns
While early concerns suggested stevia might harm kidneys, more recent studies suggest it may offer renoprotective benefits. Despite this, the whole-leaf and crude forms of stevia have not been evaluated for safety and are not FDA-approved, with some concerns about potential harm to the kidneys, reproductive system, and cardiovascular system. Patients with existing kidney disease should consult a doctor before using stevia, especially unrefined versions.
Allergies and Sensitivities
Allergies to the Asteraceae Family
Stevia is part of the Asteraceae/Compositae family, which includes common plants like ragweed, chrysanthemums, and daisies. People with known allergies to these plants may have a higher risk of developing an allergic reaction to stevia. Symptoms can include swelling, hives, or breathing difficulties.
Sensitivity to Sugar Alcohols
Many popular stevia products are not pure stevia. They are often blended with sugar alcohols like erythritol, which can cause digestive problems in some people. These symptoms can include bloating, gas, nausea, stomach pain, and diarrhea. For those who experience these issues, it is essential to check the ingredient list for sugar alcohols and choose a pure stevia product instead.
Special Populations
Pregnant and Breastfeeding Women
Regarding pregnancy and lactation, there is a distinct difference in safety between purified and crude stevia. The FDA considers high-purity steviol glycoside extracts (like Reb-A) safe when used in moderation, though comprehensive human research is limited. However, the whole-leaf and crude stevia extracts are not approved by the FDA due to safety concerns and should be avoided entirely during pregnancy and breastfeeding. Pregnant or nursing women should consult a doctor before using any stevia products.
Infants and Young Children
Infants under 12 months should not consume any sweeteners, including stevia. For older children, a concern is inadequate calorie intake from frequent consumption of stevia-sweetened foods and beverages, as children need sufficient calories for healthy growth and development.
Stevia and Your Health: A Comparison
| Feature | Pure Steviol Glycosides | Stevia Blends (with fillers) | Regular Sugar (Sucrose) |
|---|---|---|---|
| Source | Highly-purified plant extract | Plant extract + additives (e.g., sugar alcohols) | Plant extract (cane/beet) |
| Calories | Zero | Variable (often low) | High (4 kcal/gram) |
| Glycemic Index | Zero | Variable (can be high) | 65 |
| Taste Profile | Sweet, sometimes with a bitter aftertaste | Sweet, potentially with digestive side effects | Sweet, clean taste |
| Potential Health Risks | Low risk for most in moderation | Gastrointestinal issues, blood sugar spikes | Weight gain, dental issues, diabetes risk |
Understanding the Different Forms of Stevia
When deciding whether to use stevia, it's crucial to understand the form you are consuming. Stevia is available in several forms, but not all are created equal in terms of safety and FDA approval.
- High-Purity Steviol Glycosides (Reb-A): This is the refined stevia extract approved by the FDA and considered safe for consumption. These products are readily available under various brand names.
- Crude Stevia Extracts: These are less processed forms that the FDA has not approved due to insufficient safety data. They may contain other compounds and are unregulated for food use.
- Whole-Leaf Stevia: This is the most natural, unprocessed form of the stevia plant leaf. It is not FDA-approved for food use due to concerns about potential health effects, especially regarding kidneys, reproduction, and the cardiovascular system.
Conclusion
While purified stevia extract is a safe alternative to sugar for many, it is not a suitable choice for everyone. Individuals with conditions such as hypotension or certain medication regimens should be cautious and seek medical advice. Pregnant or breastfeeding women, as well as those with allergies to related plants, also need to be careful. The potential side effects from common additives like sugar alcohols in many stevia blends further emphasize the need for consumers to read labels and be informed. Before making a switch, especially if you have pre-existing health conditions or are taking prescription medications, a consultation with a healthcare provider is the safest course of action. For more information on the various types of stevia and their safety, a good resource is the Memorial Sloan Kettering Cancer Center's overview.
