Sugar alcohols are organic compounds, usually obtained from sugars. Despite the name, there is no ethanol in them. It is a white, water-soluble crystalline powder, similar to sugar, naturally found in fruits in small quantities. The most popular ones are xylitol, maltitol, sorbitol, erythritol.
Sugar alcohols have a very similar taste to sugar, are slightly less or the same sweet, but are significantly lower in calories. Sugar alcohols are characterized by a “cool” aftertaste.
The effect on blood sugar varies with sugar alcohol, but is significantly lower than sucrose’s. Some sugar alcohols’ glycemic index is as low as 0-3 (erythritol, glycerol, mannitol), others have a stronger impact on blood sugar levels. For comparison, sugar’s glycemic index is 63.
Another extraordinary feature of sugar alcohols is that they are indigestible to mouth bacteria and therefore do not cause tooth decay. Even the opposite, researches have shown that sugar alcohols have a positive effect on the microflora.
There is also the dark side of this advantage: our body does not have enzymes to fully digest sugar alcohols, so they travel to the intestines where it often cause side effects: abdominal pain, diarrhea, and discomfort. So it is important not to exceed a daily allowance of 65 g. Studies have shown that sugar-alcohol induced side effects are short term only and have no long term concequence.
Generally speaking, sugar alcohols are very controversial and everyone should decide whether or not to use them according to individual reaction and tolerance. Based on existing studies, except for possible diarrhea, there is no significant risk of using sugar alcohols. Sugar alcohols are considered safe.
But safe – does not mean healthy. Like every food additive, made in a lab rather than naturally occurring, should be treated with caution and not be used in excess.
Xylitol is one of the most popular sugar alcohols, also known as birch sugar, has traditionally been extracted from birch by breaking the tree’s structural fibers. Now it also comes from vegetable waste, wood, cotton seed, corn.
The sweetness of xylitol, in comparison with sugar, is 1:1, it has 60% of sugar calories, glycemic index: 13. It has a minty cooling aftertaste. Due to this and previously mentioned properties not to be digested by mouth bacteria, xylitol is often used in chewing gum and toothpastes. The maximum recommended daily dose is 0.3 g/kg body weight.
Xylitol is sufficiently well researched and considered safe. Nowadays it is often produced from genetically modified corn, so it is better to choose one made from birch. Xylitol is extremely toxic to dogs.
Maltitol, made from sugar maltose, is one of the most popular sugar alcohol, widely used in sugar-free products. This is due to the similarity of its chemical and flavor characteristics to regular sugar.
But maltitol is not so innocent and is considered the most aggressive of all sugar alcohols. Its sweetness, compared to sugar, is 1:0.9, it has 59% of sugar’s calories, but its glycemic index is very high – 45, close to sugar (63).
Despite the fact that it is one of the most common substitutes for sugar, its effect on blood sugar can be very high. Maltitol is also commonly associated with side effects typical of sugary alcohols: diarrhea, abdominal, abdominal pain.
It is best to avoid maltitol.
Sorbitol, industrially produced from dextrose, has 60% sweetness of sugar, slightly more calories, glycemic index – 9.
The body receives sorbitol not only with food, human cells produce it too. When too much sorbitol is absorbed inside the cells, it can have a negative effect. If you eat more than 30 g of sorbitol, you may get stomach ache, nausea, and diarrhea. Sorbitol removes water and salts from the body, which may be dangerous. It can trigger irritable bowel syndrome, interfere with absorption of fructose.
Sorbitol should better be avoided in the diet.
Erythritol is naturally found in fruits and vegetables. It is produced by fermentation of glucose. It is very low in calories (94% less sugar than sugar) and has 80% of sugar sweetness.
Erythritol has no effect on blood sugar or insulin levels, its glycemic index is 0. Safe amount is 0.7g/1 kg.
Researches do not indicate any major health problems associated with the use of erythritol up to the recommended dose. Based on many clinical studies and long-term observations in different age groups, erythritol is named as the safest sugar alcohol, followed by xylitol, which gets the silver.
The most agresive sugar alcohols are: maltitol, glucitol, mannitol, sorbitol.