Polyols, also known as sugar alcohols, are organic compounds found in many food products. They share structural similarities with both sugars and alcohols, yet possess distinct properties. These compounds play a significant role in consumer goods.
Defining Polyols
Polyols are carbohydrates featuring multiple hydroxyl (-OH) groups, characteristic of both sugars and alcohols. Unlike typical sugars, polyols have a hydrogen atom and a hydroxyl group attached to each carbon atom along a carbon chain, which gives them a different metabolic pathway. These compounds occur naturally in a variety of fruits and vegetables, such as apples, pears, peaches, and plums, as well as in mushrooms and seaweed.
Beyond their natural presence, polyols are also produced on an industrial scale through the hydrogenation of sugars. Common examples of polyols include xylitol, erythritol, sorbitol, mannitol, maltitol, lactitol, and isomalt. Each of these polyols has a different level of sweetness compared to sucrose (table sugar), with erythritol being about 70% as sweet as sugar and often used as a bulking agent.
Everyday Uses
Polyols serve various purposes across a wide range of consumer products, with their primary application being as sugar substitutes in foods and beverages. Their lower caloric content, typically ranging from 0.2 to 3 calories per gram compared to sugar’s 4 calories per gram, makes them appealing for reduced-calorie formulations. Additionally, polyols are considered non-cariogenic, meaning they do not contribute to tooth decay.
These compounds are commonly found in sugar-free chewing gums, candies, chocolates, and other confectionery items, where they provide sweetness without promoting cavities. Beyond sweetness, polyols also function as humectants, helping products retain moisture, which is particularly useful in baked goods and some cosmetic formulations. For instance, sorbitol is often used in baked goods to maintain freshness and improve texture.
Polyols also act as bulking agents, adding volume and texture to products where sugar has been reduced or removed, contributing to a mouthfeel similar to that of full-sugar products. You might encounter polyols in oral care products like toothpaste and mouthwash, where they contribute to flavor and moisture retention. Some pharmaceuticals also incorporate polyols as excipients, which are inactive ingredients that help with the formulation and delivery of medications.
How Polyols Interact with the Body
When consumed, polyols are only partially absorbed in the small intestine, unlike most sugars, which are almost completely absorbed. This incomplete absorption is a key reason for their lower caloric value, as a significant portion passes through the digestive system without being fully metabolized. Because they are not fully absorbed, polyols generally have a minimal impact on blood glucose and insulin levels, making them suitable for individuals managing their blood sugar, such as those with diabetes.
The unabsorbed polyols then travel to the large intestine, where they can be fermented by gut bacteria. This fermentation process produces gases, which can lead to common digestive effects like bloating, gas, and abdominal discomfort, especially when polyols are consumed in large quantities. Furthermore, polyols can draw water into the colon due to their osmotic properties, which may contribute to a laxative effect in some individuals. The specific type and amount of polyol consumed can influence the severity of these gastrointestinal symptoms, with some polyols like erythritol being less likely to cause digestive upset compared to others like sorbitol or mannitol.