Understanding the Different Forms of Stevia
Stevia is a plant-based, zero-calorie sweetener extracted from the leaves of the Stevia rebaudiana plant. Its sweetness comes from compounds called steviol glycosides. However, the "stevia" you see in the supermarket is not a one-size-fits-all product. The healthiest option depends on its level of processing and what it's mixed with.
Whole Green Leaf Stevia
This is the least processed and most natural form of stevia. It's simply the dried and ground leaves of the stevia plant, which results in a greenish powder.
- Pros: In its whole form, stevia retains all its natural compounds, offering a milder, more balanced sweetness. It is often preferred by those who follow a holistic or Ayurvedic approach to health. Some studies suggest whole leaf extracts may have benefits related to blood sugar and cholesterol, but research is less extensive than for purified forms.
- Cons: The FDA has not approved whole leaf stevia for use as a commercial food additive due to insufficient safety research. It is available as a dietary supplement or can be grown at home, but its flavor can be more pronounced and have a bitter or licorice-like aftertaste due to compounds other than the purest glycosides.
Purified Stevia Leaf Extract
This form is made by extracting the sweet steviol glycosides from the leaves, filtering, and purifying them. The FDA has granted "Generally Recognized as Safe" (GRAS) status to highly purified steviol glycosides, provided they contain at least 95% steviol glycosides. The most common pure extract is Rebaudioside A (Reb A).
- Reb A: The most abundant and widely used glycoside, Reb A is about 250–300 times sweeter than sugar. It is more expensive than less refined forms but offers a cleaner taste, though some still detect a bitter aftertaste, especially at high concentrations.
- Reb M and Reb D: These are newer, less abundant steviol glycosides known for having the most sugar-like taste with minimal to no bitter aftertaste. Because they are harder to extract, products containing high percentages of Reb M or Reb D are typically more expensive.
Stevia Blends
These are the most common type of stevia product found on supermarket shelves, sold under various brand names. Stevia blends combine a small amount of purified stevia leaf extract (usually Reb A) with other sweeteners or bulking agents.
- Pros: Blending helps to improve the texture and mask the lingering aftertaste associated with some pure stevia extracts. They are formulated to be measurable like sugar for baking and general use.
- Cons: These products often contain fillers like erythritol, dextrose, or maltodextrin. Erythritol, a sugar alcohol, can cause digestive discomfort in sensitive individuals. Recent studies have also linked higher erythritol blood levels to an increased risk of heart attacks and strokes. Dextrose and maltodextrin are sugars that can spike blood glucose levels, which defeats the purpose of choosing a sugar-free sweetener, especially for diabetics.
Comparison of Stevia Types
| Feature | Whole Green Leaf Stevia | Purified Stevia Leaf Extract (Reb A, Reb M) | Stevia Blends |
|---|---|---|---|
| Processing Level | Least processed; dried and ground leaves | Highly purified extraction; 95%+ steviol glycosides | Highly processed; includes fillers and additives |
| FDA Status | Not approved as a food additive | GRAS (Generally Recognized as Safe) | GRAS (components like Reb A) |
| Sweetness | Mild and balanced; contains multiple glycosides | High intensity (200-400x sweeter than sugar) | Variable; high intensity due to Reb A, plus fillers |
| Taste Profile | Earthy, often with a licorice-like aftertaste | Generally clean, but some may detect a bitter aftertaste | Variable; can have an artificial or chemical taste |
| Additives | None | None | Often contains erythritol, dextrose, or maltodextrin |
| Digestive Impact | May cause some bloating in sensitive individuals | Generally minimal | Can cause bloating and gas from sugar alcohols |
| Cost | Typically less expensive per volume | Varies; Reb M extracts are more expensive than Reb A | Varies widely by brand and ingredients |
Making the Healthiest Choice
For the average consumer focused on health, the choice comes down to weighing the benefits of purity versus flavor and convenience. The most scientifically-backed and safest option for widespread use is a high-purity stevia leaf extract, particularly those containing Reb A, Reb M, or a combination.
The Best Options
- High-Purity Reb M or Reb D: For the cleanest, most sugar-like taste without the bitterness, look for extracts with high concentrations of Reb M or Reb D. These are the most expensive but provide the best flavor profile, reducing the need for other sweeteners to mask the taste.
- Pure Reb A Extract: A more affordable and widely available option is a pure Reb A extract. While it can have a slight aftertaste, it is considered safe and is a reliable zero-calorie sweetener. The aftertaste is much less pronounced than crude stevia.
- Whole Leaf Powder (as a supplement): If you are more interested in the natural, unprocessed form and are not pregnant or have a medical condition, whole green leaf stevia can be a good option for use as a dietary supplement. It retains more of the plant's compounds but is not FDA-approved for commercial food use.
What to Avoid
To ensure you're getting the healthiest stevia, it's crucial to read the ingredients list and avoid products that use a lot of additives. Steer clear of:
- Stevia Blends with Additives: Products containing erythritol, dextrose, or maltodextrin can cause unwanted digestive side effects or blood sugar spikes. A pure extract or a blend with a proven safe filler is a better choice.
- Crude or Unapproved Stevia: The FDA has not approved crude stevia or unprocessed whole leaves for commercial food products due to a lack of safety research. These are best avoided unless you are using them as a supplement with medical guidance.
Conclusion: Prioritizing Purity Over Processing
Ultimately, the healthiest kind of stevia is one that prioritizes purity and minimally processed extraction. While the whole green leaf is the most natural form, its safety for widespread commercial use is not fully established. Therefore, high-purity stevia leaf extracts, particularly those rich in Reb M or Reb A, are the safest and healthiest choice for most people. By choosing a pure extract and avoiding blends with questionable additives like sugar alcohols or fillers, you can enjoy the sweetness of stevia without compromising your health. The key takeaway is to always read the ingredient list, opting for a product with the fewest, purest ingredients possible.
Choosing the Healthiest Stevia: Your Quick Guide
- Check the Label: Always read the ingredients list to ensure you are buying pure stevia leaf extract and not a blend with added fillers like erythritol or dextrose.
- Prioritize Purity: High-purity extracts (95% or more steviol glycosides) are considered safest by regulatory bodies like the FDA.
- Opt for Reb M or Reb A: For the best taste and a clean profile, look for extracts with high concentrations of Rebaudioside M (Reb M) or Rebaudioside A (Reb A).
- Be Wary of Blends: Be cautious of products that mix stevia with other sweeteners, as these can contain unwanted additives that cause digestive issues or affect blood sugar.
- Consider the Source: If you prefer the least processed form and are not pregnant, whole green leaf stevia is an option, but note it is not FDA-approved for commercial use.
- Consult a Professional: If you have specific medical conditions, particularly diabetes or hypertension, it is wise to consult a doctor before incorporating stevia regularly.
Frequently Asked Questions
What makes some stevia taste bitter? Some stevia products contain a higher concentration of the steviol glycoside, stevioside, which has a bitter aftertaste. Higher-purity extracts, especially those rich in Reb M, are specifically processed to minimize this bitterness.
Is it safe to consume stevia daily? Yes, purified stevia leaf extract is considered safe for daily consumption within the acceptable daily intake (ADI) levels set by health organizations. However, the same may not be true for blends containing fillers or excessive additives.
Can diabetics use stevia safely? Yes, pure stevia has a glycemic index of zero and does not raise blood sugar levels, making it a safe sugar alternative for people with diabetes. However, diabetics must carefully check the label on stevia blends, as some additives like maltodextrin can affect blood glucose.
Is whole leaf stevia healthier than purified extract? While whole green leaf stevia is less processed, it is not considered safer or healthier than purified extract by regulatory bodies like the FDA due to a lack of research. Purified extracts have undergone extensive safety testing and are widely approved for food use.
Can stevia cause digestive problems? Pure stevia itself is not known to cause digestive issues, but many commercial blends contain sugar alcohols like erythritol, which can lead to bloating, gas, and stomach upset in some individuals.
What are Reb A, Reb M, and Reb D? These are specific steviol glycosides, or sweet compounds, found in the stevia plant. Reb A is the most common and affordable, while Reb M and Reb D are prized for their clean, sugar-like taste and lack of bitterness, though they are more expensive to produce.
What's the best stevia for baking? For baking, a pure granulated or powdered stevia extract is recommended. Avoid blends with sugar alcohols if you are sensitive to them, and be aware that stevia is much sweeter than sugar, so you will need to adjust the amount accordingly. Pure stevia adds sweetness but not bulk, so recipes may require modification for texture.
