Erythritol is a popular sugar replacement, especially for those monitoring carbohydrate intake. The Glycemic Index (GI) ranks foods based on how quickly they raise blood glucose levels after consumption, using pure glucose (GI 100) as the reference point. Erythritol is categorized as a non-nutritive sweetener because it provides almost no calories or absorbable carbohydrates. The most significant finding is that this compound possesses a Glycemic Index of zero.
Defining Erythritol and Sugar Alcohols
Erythritol is classified as a polyol, a type of carbohydrate commonly known as a sugar alcohol. Despite the name, this compound does not contain ethanol and is neither sugar nor alcohol in the conventional sense. It is a four-carbon organic compound found naturally in small quantities in various fruits, such as grapes, pears, and watermelon, as well as in fermented foods.
Commercial erythritol is produced on a large scale through a fermentation process. This process typically begins by extracting glucose, often from cornstarch. Specific yeast strains, such as Moniliella pollinis, are then used to ferment the glucose, converting it into erythritol.
Once processed, erythritol is purified and crystallized into a white, granular powder that resembles table sugar. It provides a mild sweetness, generally rated as 60% to 70% the sweetness of sucrose. Erythritol is favored among sugar alcohols for its clean taste and minimal aftertaste, although it can produce a slight cooling sensation in the mouth when dissolved.
Why Erythritol Has a Glycemic Index of Zero
The zero rating on the Glycemic Index is a direct result of how the body handles the erythritol molecule. Unlike traditional sugars, which are broken down by digestive enzymes before absorption, erythritol is absorbed rapidly in the small intestine. However, the human body does not possess the necessary enzymes to metabolize this compound for energy.
Because it is not metabolized, erythritol bypasses the body’s main carbohydrate pathway. It is not converted into glucose, which is the mechanism that triggers a rise in blood sugar and a subsequent insulin response. The lack of glucose conversion ensures the sweetener has no measurable impact on blood glucose levels.
Up to 90% of ingested erythritol is absorbed into the bloodstream from the small intestine. From the bloodstream, it circulates briefly before being quickly excreted. The majority of the compound leaves the body unchanged, primarily through urine.
This process of absorption without metabolism or conversion to glucose gives erythritol its zero-calorie status for labeling purposes. While it technically contains a trace amount of energy at about 0.24 calories per gram, this is significantly lower than the four calories per gram found in sugar. The rapid and complete excretion of the molecule ensures it does not affect blood glucose or insulin levels.
Practical Comparisons to Other Sweeteners
Erythritol’s GI of zero places it in a category with other non-caloric sweeteners, but it performs better than some other sugar alcohols. Sucrose, or standard table sugar, has a GI of about 65 and delivers four calories per gram, causing a significant blood glucose spike. Non-nutritive alternatives like stevia and sucralose also have a GI of zero, but they are hundreds of times sweeter than sugar and are used in much smaller quantities.
Other polyols, such as maltitol, have a GI that can range from 35 to 52, which is high enough to affect blood sugar, especially in individuals with impaired glucose tolerance. Xylitol, another common sugar alcohol, has a low GI of approximately 7 to 13 but still provides 2.4 calories per gram. Erythritol’s GI of zero makes it a better choice for those focused on strict blood sugar management.
The combination of a zero Glycemic Index and negligible net carbohydrates makes erythritol a suitable sugar replacement for certain dietary approaches. People following ketogenic, low-carb, or diabetic diets often use it because it allows for sweetness without compromising glucose control.