Sugar alcohols

Sugar alcohols have been a popular alternative to sugar for decades. They look and taste like sugar, but they provide fewer calories and have fewer negative health effects. In fact, many studies show that sugar alcohols can lead to improved health. This article looks at sugar alcohols and their effects on health.

What are sugar alcohols?

Sugar alcohols are a category of sweet carbohydrates. Because sugar alcohols are partially resistant to digestion, they act much like dietary fiber. They are also a type of FODMAP (fermentable oligo-, di-, mono-saccharides and polyols), which can cause digestive discomfort and bloating in some people. As the name suggests, sugar alcohols are a kind of hybrid of sugar molecules and alcohol molecules. Despite the "alcohol" part of the name, sugar alcohols do not contain ethanol - the alcohol compound that makes you drunk. Sugar alcohols are therefore also safe for dry alcoholics. Some sugar alcohols occur naturally in fruit and vegetables. However, most sugar alcohols are produced from other types of sugar such as glucose from corn starch. As sugar alcohols have a similar chemical structure to sugar, they activate the tongue's sweet receptors. Unlike artificial and low-calorie sweeteners, sugar alcohols provide calories, albeit fewer calories than pure sugar.

Summary: Sugar alcohols are a category of sweet carbohydrates that occur naturally or are made from other sugars. Sugar alcohols are widely used as sweeteners.

Common types of sugar alcohols

Several types of sugar alcohols are used as sweeteners in food production. These sugar alcohols differ in taste, calorie content and health effects.

Xylitol

Xylitol is the most commonly used and best-studied sugar alcohol. It is a commonly used ingredient in sugar-free chewing gum, sweets and oral care products such as toothpaste. Xylitol is about as sweet as sugar, but provides 40% fewer calories. Apart from the fact that xylitol can cause digestive problems when consumed in large quantities, this sugar alcohol is well tolerated (1).

Erythritol

Erythritol is another sugar alcohol that has an excellent taste. Erythritol is produced by fermenting the glucose contained in corn starch and has about 70% of the sweetening power of sugar, while providing only 56% of the calories of sugar. Together with the low-calorie sweetener stevia, erythritol is the main ingredient in the popular Truvia sweetener blend. Erythritol does not have the same side effects on the digestive system that most sugar alcohols have, as erythritol does not reach the colon intact in significant amounts. Instead, this sugar alcohol is absorbed into the bloodstream and then excreted unchanged in the urine (2).

Sorbitol

Sorbitol has a soft mouthfeel and a cool taste. Sorbitol has about 60% of the sweetening power of sugar and provides about 60% of the calories of sugar. This sugar alcohol is a common ingredient in sugar-free foods and beverages. Sorbitol has very little effect on blood sugar and insulin levels, but can cause digestive discomfort (3).

Maltitol

Maltitol is made from the sugar maltose and has a taste that is quite similar to real sugar. Maltitol has about 90% of the sweetening power of sugar with about half the calories. Even though products containing maltitol are advertised as 'sugar-free', the body absorbs some of this sugar alcohol, leading to a significant rise in blood sugar levels (4). If you suffer from diabetes, you should be careful with low-carb products sweetened with maltitol and make sure you monitor your blood sugar levels carefully.

Other sugar alcohols

Other sugar alcohols commonly found in foods include mannitol, isomaltitol, lactitol and hydrogenated starch hydrolysates.

Summary: Many different sugar alcohols are found in the modern diet. These include xylitol, erythritol, sorbitol, maltitol and many others.

Glycaemic index and influence on blood sugar levels

The glycemic index (GI) is a measure of how quickly foods raise blood sugar levels. Consumption of foods that have a high GI has been linked to obesity and numerous metabolic health issues (5, 6).

The figure below compares the GI of different sugar alcohols with sucrose - ordinary white table sugar (7).

Figure 1: Glycemic index of some sugar alcohols compared to table sugar (sucrose) As can be seen, some sugar alcohols have a negligible effect on blood glucose levels, which is virtually zero for erythritol and mannitol. For people suffering from metabolic syndrome, prediabetes or diabetes, most sugar alcohols - apart from perhaps maltitol - can therefore serve as excellent alternatives to sugar.

Summary: Most sugar alcohols have little or no effect on blood sugar and insulin levels - with the exception of maltitol.

Sugar alcohols can improve dental health

Tooth decay is one of the well-documented side effects of excessive sugar consumption. Sugar serves as food for certain bacteria in the mouth, which then multiply and secrete acids that dissolve the protective enamel of the teeth. In contrast to sugar, sugar alcohols such as xylitol, erythritol and sorbitol can even protect against tooth decay (8). This is one of the main reasons why sugar alcohols are so popular in many types of chewing gum and toothpaste. Xylitol is well known for its positive effects on dental health and has been extensively studied in this regard (9, 10). Bacteria in the oral cavity ingest xylitol as supposed food, but are unable to metabolize this sugar alcohol, causing it to block their metabolic machinery and inhibit their growth (11). Erythritol has not been studied as extensively as xylitol in this regard, but a three-year study of 485 schoolchildren concluded that erythritol may provide better protection against tooth decay than xylitol and sorbitol (12).

Summary: Xylitol, erythritol and sorbitol lead to improvements in dental health. Xylitol has been the best studied in this regard, but there is evidence that erythritol may be the most effective.

Other benefits

Sugar alcohols have a number of other potential benefits that are worth mentioning.

Prebiotics: Sugar alcohols may serve as food for the "friendly" bacteria in the gut and have similar prebiotic effects as dietary fiber (13, 14, 15).
Bone health: Many studies conducted with rats suggest that xylitol may increase bone volume and mineral content, which should protect against osteoporosis (16, 17).
Skin health: Collagen is the primary structural protein in skin and connective tissue. Studies in rats have shown that xylitol can increase collagen production (18, 19).
Summary: Sugar alcohols may serve as food for "good" gut bacteria and may have beneficial effects on skin and bone according to animal studies. Digestive problems

The main problem with sugar alcohols is that they can cause digestive problems, especially when consumed in large quantities. The body cannot digest most of these sugar alcohols, so they pass intact into the large intestine where they are metabolized by intestinal bacteria. If you consume a lot of sugar alcohols in a short period of time, you may experience bloating, a distended stomach and diarrhea. If you suffer from irritable bowel syndrome or are sensitive to FODMAPs, then you may want to avoid sugar alcohols altogether. Sorbitol and maltitol seem to have the most adverse side effects in this regard, while erythritol and xylitol cause the fewest adverse symptoms (20).

Summary: When consumed in large quantities, most sugar alcohols can cause significant digestive problems. The effect depends on the individual and the type of sugar alcohol consumed.

Xylitol is toxic to dogs

Xylitol is well tolerated by humans but highly toxic to dogs. When dogs eat xylitol, their bodies mistake it for sugar and begin to produce large amounts of insulin. When insulin levels rise, the cells begin to pull sugar from the bloodstream. This can lead to severe hypoglycemia and can be fatal (21). For this reason, all products containing xylitol should be stored out of the reach of dogs. This effect appears to be exclusive to xylitol. Only xylitol - and no other sugar alcohol - appears to have this effect.

Summary: Xylitol is toxic to dogs and should therefore be kept out of the reach of dogs.

Which sugar alcohol is the healthiest?

Of all the sugar alcohols, Erythritol seems to be the best option. Erythritol provides almost no calories, has no effect on blood sugar levels and causes significantly fewer digestive problems than other sugar alcohols. Erythritol is also good for teeth and will not harm your dog. In addition, this sugar tastes great - and is basically nothing more than sugar without the calories.

Summary: Erythritol is generally considered to be the healthiest sugar alcohol. Erythritol is calorie-free, does not raise blood sugar levels and is less likely to cause digestive problems than other sugar alcohols.

Conclusion

Sugar alcohols are popular, low-calorie sweeteners. They are not artificial sweeteners. They are partially resistant to digestion, although certain sugar alcohols such as maltitol can cause an increase in blood sugar levels. Although they are well tolerated, larger amounts of some sugar alcohols such as sorbitol can cause a bloated feeling and diarrhea. Erythritol appears to have the least side effects and may also be a good choice for people who are intolerant to FODMAPs.

References

https://www.healthline.com/nutrition/sugar-alcohols-good-or-bad