Understanding Sugar Alcohols
Both maltitol and erythritol belong to a class of sweeteners known as sugar alcohols, or polyols. They provide sweetness with fewer calories because they are not completely absorbed or metabolized by the body. The primary function of these sugar substitutes is to satisfy sweet cravings without the high caloric load or blood sugar spike associated with traditional sugar.
What is Maltitol?
Maltitol is a sugar alcohol made from the sugar maltose, which is derived from starch. It is approximately 75–90% as sweet as sugar and has a similar taste and texture, making it a popular choice for sugar-free candies and chocolates. However, this similarity comes with significant trade-offs regarding its effect on the body. Maltitol contains about 2.1 calories per gram and has a moderate glycemic index (GI) of around 35–52.
The Case Against Maltitol
Maltitol's major downside is its impact on the digestive system. Because it is only partially absorbed in the small intestine, the undigested portion travels to the large intestine where it is fermented by gut bacteria. This process can lead to significant gastrointestinal distress, including:
- Bloating
- Gas
- Cramping
- Diarrhea, often called a "laxative effect"
These side effects are dose-dependent, and the FDA requires products containing more than 50 grams of sugar alcohols to carry a warning label. Additionally, maltitol's moderate glycemic index means it can still raise blood sugar levels, which is a concern for individuals with diabetes or those following strict low-carb and keto diets.
What is Erythritol?
Erythritol is a sugar alcohol that is naturally found in some fruits and fermented foods. Commercially, it is produced by fermenting glucose with yeast. It is 60–80% as sweet as sugar but contains almost zero calories (0.24 calories per gram).
The Argument for Erythritol
Erythritol is widely praised for its minimal impact on blood sugar. It has a glycemic index of zero and is absorbed into the bloodstream before reaching the colon, meaning it does not get fermented by gut bacteria in the same way as maltitol. This results in significantly better digestive tolerance. For this reason, it has become a preferred sweetener for many on keto and low-carb diets. Other benefits include:
- Low calories: Nearly zero calories per gram.
- Dental health: Does not contribute to tooth decay.
- Antioxidant properties: Some studies suggest it has antioxidant effects.
The Recent Concerns About Erythritol
Despite its advantages, a recent study published in Nature Medicine and highlighted by the Cleveland Clinic raised concerns linking higher erythritol levels in the blood to an increased risk of heart attack and stroke. The study was observational, meaning it showed an association rather than causation, and the results are a subject of ongoing debate and further research. This information has introduced a note of caution for some consumers, particularly those with pre-existing cardiovascular risks.
Which is worse, maltitol or erythritol? A comparative analysis
When stacked against each other, the differences between these two sugar alcohols become clear. Erythritol is almost universally regarded as the better choice for managing blood sugar and avoiding digestive upset. However, recent safety concerns surrounding erythritol must also be considered.
Comparison Table: Maltitol vs. Erythritol
| Feature | Maltitol | Erythritol |
|---|---|---|
| Caloric Content | ~2.1 calories/gram | ~0.24 calories/gram |
| Glycemic Index | 35–52 (moderate) | 0 (negligible) |
| Digestive Tolerance | Poor; can cause significant gas, bloating, and diarrhea | Generally well-tolerated, minimal digestive issues |
| Blood Sugar Impact | Can cause a rise in blood sugar and insulin | No significant impact on blood sugar or insulin |
| Sweetness (vs. sugar) | 75–90% | 60–80% |
| Aftertaste | Minimal or none | Can have a cooling aftertaste |
| Best for Keto? | Not ideal due to higher GI and carbs | Preferred choice due to zero GI |
Conclusion
For most people aiming to control blood sugar or avoid digestive distress from sugar alcohols, erythritol is the clear winner. Its zero glycemic index and excellent digestive tolerance make it the superior choice for low-carb and ketogenic diets. In contrast, maltitol's moderate glycemic impact and pronounced laxative effects make it the worse of the two for many individuals, particularly those with diabetes or irritable bowel syndrome.
However, the recent cardiovascular concerns associated with erythritol suggest that caution and moderation are wise for all sugar alcohols, regardless of type. As always, consuming whole, unprocessed foods is the best strategy. For those who choose to use sweeteners, erythritol offers a more favorable profile for metabolic and digestive health, but staying informed on ongoing research is crucial.
