SUGAR ALCHOLS (POLYOLS)

Sugar alcohols, also known as polyols has been in use for decades as an alternative to sugar. They are classified as carbohydrates and occur naturally in fruits and vegetables although they now widely consumed in sugar-free and reduced-sugar foods. Just as sucrose, the sweetness of sugar alcohols varies from 25% to 100%. When eaten in sugar-free foods, sugar alcohols are slowly absorbed by the body where it is converted into energy using almost zero insulin. Sugar alcohols pass into the bloodstream partially but mostly through the small intestine, while a small percentage passes through the large intestine, after being fermented by colonic microbes. Sugar-free products that contain sugar alcohols are gums, candy, ice cream, baked food, and fruit spreads; oral hygiene products like toothpaste, mouthwashes, and breath mints; medicines like cough syrups, and lozenges; and in sports nutrition products like protein powders, pre-workout supplements, and low-carb products. All sugar alcohols are recognized as safe, regulated by the Food and Drug Administration, FDA in the United States and other similar organizations worldwide, as well as approved as food additives in other products like cosmetics by other health authorities. Based on their chemical structures, sugar alcohols can be classified into three groups;

• Monosaccharide-derived polyols (e.g., Sorbitol, Mannitol, Xylitol, and Erythritol)
• Disaccharides-derived polyols (e.g., Isomalt, Lactitol, and Maltitol)
• Polysaccharide-derived mixture (e.g., Hydrogenated starch hydrolysates mixtures)

SORBITOL

This is manufactured by hydrogenating – adding hydrogen, to dextrose (glucose) produced from cornstarch. Sorbitol is present in some fruits and is about 60% as sweet as sucrose, and considered to have 2.6cal per gram. FDA regulates the amount of Sorbitol permitted in any food, which must not exceed good manufacturing process. If for any reason the amount of Sorbitol in the food reaches 50grams (1-3/4 ounces), then the food must be labeled with, “Excess consumption may have a laxative effect.” Sorbitol can be found in both hard and soft candies, flavored jam, jelly spreads, baked foods and baking mixes, gum, and cough syrups.

MANNITOL

This sugar alcohol is manufactured from fructose, also gotten from cornstarch through hydrogenation. This process alters the fructose structure to sugar mannose, hence becoming mannitol. Naturally, mannitol is found in fruits, leaves, strawberries, celery, onions, pumpkins, and mushrooms, and is about 60% as sweet as sucrose, and considered to have 1.6cal per gram. The FDA regulates this calorific value and the quantity to be added to any food. Therefore any food that will contain mannitol addition of 20 grams (less than 3/4 of an ounce) must be labeled with the statement, “Excess consumption may have a laxative effect.” Mannitol can be used in hard and soft candies, confections and frostings, chewing gum, and cough syrups.

MALTITOL

The hydrogenation of maltose, a glucose-glucose disaccharide that is derived from cornstarch produces Maltitol. It is about 90% as sweet as sugar and therefore can serve as a direct sugar replacement. It can also be used in same food category as Sorbitol and Mannitol.

HYDROGENATED STARCH HYDROLYSATE

This is a polyol produced by the partial hydrolysis of starch gotten from corn as well as further hydrogenation of the various starch fragments or dextrins. Once a product contains more of hydrogenated dextrins than Sorbitol or Maltitol, then it is known as hydrogenated starch hydrolysate (HSH). Depending on the composition, HSH is about 20%-50% of sugar. This is why an HSH product containing more of Maltitol would be sweeter than that containing Sorbitol. Hydrogenated starch hydrolysate can be blended with other sweeteners, both caloric and artificial, and can serve the same purpose that other common sugar alcohols serve in a product.

XYLITOL

This is a polyol that is just as sweet as sugar. It is a manufacturer’s choice in producing sugar-free chewing gums, candies and chewable vitamins because it has a mint flavor and gives a cooling effect when compared to other sugar alcohols. Xylitol has the approval of FDA to be added to special diets meant for a diabetic patient.

ISOMALT

Isomalt is not as sweet as sugar, and do not produce a cooling effect in the mouth like other polyols. It is manufactured from sugar where the fructose portion of glucose is converted to equal amounts of Sorbitol and Mannitol. Hence, it is a mixture of two disaccharides, glucose –Sorbitol and glucose- Mannitol. Isomalt is considered to have 2cals per gram and can be heated with no change in texture or loss in sweetness because of the presence of its glucose-fructose bond. This polyol is used in making hard and soft candies, chocolates, ice cream, jams and preservatives, fillings and fondants, baking items, chewing gum and cough syrups.

LACTITOL

Lactose is a rich by-product of cheese and processed dairy foods. Lactitol is slightly less than half as sweet as sugar, with two calories per gram. This sugar polyol is often mixed with artificial sweeteners and can be used in reduced-sugar or sugar-free products, frozen dairy desserts, candies, and chocolate confections. Recent laboratory studies suggest that Lactitol can promote the growth of two bacteria necessary for the growth of the large intestines.

ERYTHRITOL

This is the newest form of sugar alcohol and is produced through fermentation of cornstarch unlike the hydrogenation of the other polyols. With 70% sweetness levels of sucrose and mild cooling effect in the mouth, Erythritol is used more for confectioneries, baked products, chewing gum, and beverages.

Sugar alcohols are quite useful in various ways that are beneficial to our health. 

• They do not affect Blood Sugar or Insulin – Sugar alcohols have a low glycemic index, which is a measure of how food can quickly raise the blood sugar levels. Foods that are high in glycemic index are normally associated with obesity and other health problems. However, most sugar alcohols rarely affect the blood sugar levels and as such recommended as an excellent alternative to sugar for people that suffer metabolic syndrome, pre-diabetes or diabetes.
• They are helpful for improving dental health – Tooth decay has been attributed to excess sugar consumption. This is because some bacteria in the mouth feed on the sugar, thereby multiplying and secreting destructive acids which destroy the enamel that would have protected the teeth. Xylitol, Sorbitol, and Erythritol are all effective towards improving dental health and protects against tooth decay. It is a known fact that some bacteria found in the mouth feed on Xylitol, they, however, do not metabolize the sugar alcohol, thus enabling the Xylitol to clog their metabolic machinery and inhibit their growth. This is why sugar alcohols are used in chewing gums and toothpaste.

IN CONCLUSION

If you plan to substitute sugar and other sweeteners in your diet, sugar alcohol is what you need. They have a negligible effect on blood sugar level and highly recommended for people with metabolic syndrome or diabetes.

Note: Over consumption of sugar alcohols can cause gastric distress. I recommend using erythritol as studies suggest it does not have the same gastric effect as the other sugar alcohols.