Sugar Alcohols: Keto's Hidden Enemy

Sugar alcohols are sugar compounds with a similar chemical structure to glucose but with an added hydroxyl group. They are often used as sugar substitutes in products labelled as sugar-free or no added sugar, as they are sweet but yield fewer calories and carbohydrates. While they can be a good option for people on the keto diet, who need to keep their blood sugar levels low, some sugar alcohols are better than others. Erythritol, for example, has a glycemic index of 0 and is well-tolerated by most people. On the other hand, maltitol has been shown to have negative side effects, including gastrointestinal issues and a more significant impact on blood sugar levels.

Sugar alcohols can cause digestive issues such as bloating, gas, stomach ache, and diarrhoea

Some people are more sensitive to sugar alcohols than others and may experience digestive issues even when consuming small amounts. Individuals with irritable bowel syndrome (IBS) or other inflammatory diseases are more likely to experience negative side effects such as bloating, gas, and diarrhoea.

The type of sugar alcohol also plays a role in the severity of digestive issues. Maltitol, for example, is known to have a potent laxative effect and is often listed as a warning on sugar-free products. On the other hand, erythritol is generally well-tolerated and causes fewer symptoms than other sugar alcohols.

The side effects of sugar alcohols are dose-dependent, meaning the more you consume, the more likely you are to experience digestive issues. Additionally, consuming sugar alcohols with other carbohydrates can worsen the symptoms.

It is important to note that sugar alcohols are not the same as artificial sweeteners like aspartame and saccharin. While both are manufactured, sugar alcohols have fewer calories and are not as sweet as artificial sweeteners.

To avoid digestive issues, it is recommended to consume sugar alcohols in moderation and be mindful of the type and amount you are consuming.

They can cause an increased risk of heart attack, stroke, and even death

Sugar alcohols are commonly used as sugar substitutes in products labelled as "sugar-free", "low-carb", "keto-friendly", or "diabetes-friendly". They are often marketed as having zero calories and carbohydrates, making them attractive to people on the ketogenic diet. However, the excessive consumption of sugar alcohols can lead to serious health risks, including an increased risk of heart attack, stroke, and even death.

Sugar alcohols, also known as polyols, are sugar compounds with a similar chemical structure to glucose but with an attached hydroxyl group (-OH), which gives them alcohol-like properties. They are only partially digested and absorbed in the small intestine, with the remainder being broken down by bacteria in the large intestine. This breakdown process can lead to the production of gas and a laxative effect, resulting in gastrointestinal (GI) disturbances such as bloating, stomach cramps, and diarrhoea. While these side effects are already concerning, recent studies have revealed even more alarming consequences of sugar alcohol consumption.

Research led by Dr Stanley Hazen, a physician-scientist who chairs the department of metabolic sciences at the Cleveland Clinic, has linked sugar alcohols to an increased risk of major adverse cardiovascular events. Specifically, the study found that circulating levels of xylitol and erythritol were associated with a heightened risk of heart attack, stroke, and death. While association does not equal causation, subsequent studies using blood, platelets, and non-human models have provided further evidence of the detrimental effects of these sugar alcohols.

The concern is that sugar alcohols may be inadvertently increasing the risk of heart attack and stroke in individuals who consume them, particularly those with diabetes who are already at a higher risk for major heart events. Dr Hazen's research suggests that just one scoop of keto-friendly ice cream, which can contain up to 30 grams of xylitol, is enough to agitate the platelets and make them more prone to forming clots. This increased risk of clotting can last for about four to six hours or until more xylitol-containing foods are consumed. When it comes to erythritol, the risk can persist for several days after consumption.

It is important to note that the potential dangers of sugar alcohols extend beyond the well-known GI issues. While these sweeteners may help reduce carbohydrate intake, their risks may outweigh the benefits. As with most foods, moderation is key, and it is advisable to focus on consuming whole foods instead of heavily processed products laden with sugar alcohols.

Sugar alcohols are not natural and are often manufactured in a lab

Sugar alcohols are often manufactured in a laboratory. While they do occur naturally in certain fruits and vegetables, most of the sugar alcohols used in food products are commercially made in a lab.

Sugar alcohols are a mixture of alcohol and sugar molecules. They are similar in structure to glucose but with an added hydroxyl group. This gives them a sweet taste, but they are digested differently from glucose. Because of this, they are only partially digested and yield fewer calories and carbohydrates. This makes them a popular choice for people on the keto diet, who are looking to reduce their sugar intake.

The most common sugar alcohols include erythritol, isomalt, maltitol, sorbitol, and xylitol. These are often used to sweeten sugar-free or diet products like gum, yogurts, ice cream, and salad dressings.

While sugar alcohols can be a helpful alternative to sugar, it's important to be aware of their potential risks. They can cause digestive issues, such as bloating, diarrhea, and stomach aches, especially when consumed in excess. Additionally, new research has linked them to an increased risk of heart attack and stroke.

They can be dangerous for animals, for example, xylitol is lethal to dogs

Sugar alcohols are not always safe for animals. For example, xylitol is highly toxic to dogs and can be lethal even in small quantities. Xylitol is a common sugar substitute found in sugar-free chewing gum, breath mints, candies, baked goods, and even some medications and skincare products. It is also known as birch sugar and is produced by processing the bark from birch trees or corncob remnants from ethanol plants.

When ingested by dogs, xylitol can cause a rapid and life-threatening drop in blood sugar, leading to hypoglycemia, vomiting, loss of coordination, seizures, and even death. As little as 500 mg of xylitol can sicken an average-sized dog and kill a smaller one. This amount is often found in just one stick of gum, making it easily accessible to dogs and extremely dangerous.

The toxicity of xylitol in dogs is due to their bodies' unique response to the substance. While xylitol consumption is considered harmless for humans, it triggers a dangerous chain reaction in dogs, leading to life-threatening toxicosis. Ingesting more than 0.1 g/kg of xylitol can cause hypoglycemia in dogs, while consuming over 0.5 g/kg can result in acute liver failure.

To prevent accidental poisoning, it is crucial for dog owners to be aware of the dangers of xylitol and to keep any products containing this substance out of their pets' reach. Always seek immediate veterinary attention if you suspect your dog has ingested xylitol, as rapid decontamination and treatment are essential for the dog's survival.

Sugar alcohols can cause weight gain

Sugar alcohols are often marketed as a healthier alternative to sugar, and while they do have some benefits, they can also cause weight gain.

Firstly, sugar alcohols are not as easily digestible as sugar. This means that they can cause digestive issues such as bloating, gas, and diarrhoea, especially when consumed in large quantities. These issues can be particularly problematic for people with irritable bowel syndrome (IBS) or other digestive sensitivities. The consumption of sugar alcohols can also have a laxative effect, which may be undesirable for some people.

Secondly, sugar alcohols can still contribute to weight gain, despite their lower calorie content. A study of college students found that consuming high levels of dietary erythritol was associated with weight gain, specifically increased belly fat. This may be due to the fact that sugar alcohols can still contain carbohydrates and calories, and if consumed in excess, can lead to a positive energy balance and subsequent weight gain. Additionally, the "Snack Well effect" is a risk of consuming sugar alcohols, where dieters may overindulge in sweet treats containing sugar alcohols because they are perceived as healthier options.

Furthermore, sugar alcohols can also have a negative impact on gut health. They are not well absorbed and can inhibit the growth of beneficial gut bacteria, reducing the health benefits associated with a diverse microbiome.

Therefore, while sugar alcohols may have some benefits in terms of reduced calorie intake, they can also contribute to weight gain and have other negative impacts on the body. It is important to consume sugar alcohols in moderation and be aware of their potential drawbacks, especially for individuals with digestive sensitivities or those trying to manage their weight.

Frequently asked questions