Understanding Monk Fruit Side Effects
Monk fruit, or luo han guo, is a small melon whose extract is used as a zero-calorie, zero-carbohydrate sweetener. The sweetness comes from compounds called mogrosides. While the pure extract is largely considered safe by the FDA, many commercial products are not purely monk fruit, which is where most potential side effects arise.
Gastrointestinal Issues from Fillers
One of the most significant causes of digestive discomfort is the addition of sugar alcohols, such as erythritol, to many monk fruit products. Erythritol is added to provide bulk and a more sugar-like texture since pure monk fruit is intensely sweet. However, when consumed in large quantities, sugar alcohols can cause gastrointestinal distress.
Common GI side effects from monk fruit products containing fillers include:
- Bloating
- Gas
- Diarrhea
- Stomach cramps
Cardiovascular Risk Linked to Erythritol
A February 2023 study published in Nature Medicine raised significant concerns about erythritol. The study linked high levels of erythritol in the blood with an increased risk of heart attack, stroke, and blood clot formation in individuals with pre-existing cardiovascular risk factors. This does not mean pure monk fruit extract is dangerous, but it highlights the importance of checking ingredient lists for blended sweeteners.
Allergic Reactions
Although rare, allergic reactions to monk fruit are possible. Monk fruit belongs to the gourd family (Cucurbitaceae), which also includes squash, melons, and cucumbers. Individuals with known allergies to these plants may have a higher risk of reacting to monk fruit.
Potential Stevia Side Effects
Stevia is derived from the leaves of the Stevia rebaudiana plant. Like monk fruit, the highly purified steviol glycosides found in most consumer products are FDA-approved and considered safe for consumption. The potential side effects are often related to the purity of the product or individual sensitivities.
Digestive Problems
Similar to monk fruit, many stevia-based sweeteners contain sugar alcohols, particularly erythritol, which can cause digestive symptoms like gas and bloating. While pure, high-purity stevia extract is generally not associated with these issues, the fillers are common culprits for those with a sensitive digestive system.
Allergic and Cross-Reactive Reactions
Some individuals with allergies to plants in the Asteraceae family, such as ragweed, daisies, or chrysanthemums, may experience a cross-reactive allergic reaction to stevia. Symptoms can include hives, swelling, or digestive upset.
Gut Microbiome Impact
Research on stevia's impact on gut bacteria is mixed and ongoing. Some animal studies have suggested that stevia might disrupt the gut microbiome, but recent human studies have not found significant changes with moderate use. This remains an area of active research.
Medication Interactions
Stevia may have a blood-pressure-lowering effect and can lower blood sugar levels. This can be a risk for individuals taking blood pressure or diabetes medications, as it could cause blood pressure or blood sugar to drop too low. Stevia may also interfere with the body's ability to excrete lithium.
Monk Fruit vs. Stevia: Side Effects Comparison
| Feature | Monk Fruit | Stevia |
|---|---|---|
| FDA Status | Highly purified extract is GRAS. | Highly purified extract is GRAS. Crude extracts are not approved. |
| Gastrointestinal Issues | Issues mostly tied to added sugar alcohols like erythritol. | Issues can arise from sugar alcohol fillers and in some individuals, the stevia itself. |
| Aftertaste | Generally has a less pronounced aftertaste than stevia, sometimes described as fruity. | Some people report a bitter or metallic aftertaste. |
| Erythritol Risk | Found in many blended monk fruit products, carrying the same cardiovascular risks. | Often blended with erythritol, posing the same risk. |
| Allergy Risk | Rare; cross-reactivity risk for those allergic to the gourd family (Cucurbitaceae). | Rare; cross-reactivity risk for those allergic to the Asteraceae (ragweed) family. |
| Drug Interactions | Limited research available; general medical advice is to consult a doctor, especially for underlying conditions. | Can interact with medications for diabetes, high blood pressure, and lithium. |
| Gut Microbiome | Early research is ongoing, but less evidence of disruption than with some artificial sweeteners. | Research is mixed; some studies suggest potential disruption, while recent human trials show no significant change. |
How to Safely Consume Monk Fruit and Stevia
- Read Labels Carefully: Always check the ingredients list for added fillers. Seek out products that are pure monk fruit or stevia extract to minimize potential side effects from sugar alcohols or other bulking agents.
- Start Small: Begin with a small amount to assess your body's individual tolerance, especially for digestive sensitivity or potential allergies.
- Use Moderation: Even pure extracts should be used in moderation as part of a balanced diet. Relying heavily on any single sweetener is not recommended.
- Consult a Professional: If you are pregnant, have underlying health conditions, or take specific medications, talk to your doctor before adding these sweeteners to your diet.
Conclusion: Choosing the Right Sweetener for You
Both monk fruit and stevia are generally safe for most people when consumed in moderation as highly purified extracts. However, the most commonly reported side effects—like digestive upset and the risk of blood clotting associated with erythritol—are typically caused by the fillers and additives found in many commercial blends. Stevia also carries specific risks for those with ragweed allergies and individuals on certain medications. The key to mitigating these side effects is to choose pure, single-ingredient products and always read the label. By doing so, you can enjoy the sweet taste of these natural alternatives with greater peace of mind.
For more information on erythritol and its effects on cardiovascular health, you can consult this CNN report: Erythritol, an ingredient in stevia, linked to heart attack, stroke risk in study.
