Diabetes and the use of sugar substitutes

As the prevalence of diabetes continues to rise in Canada, managing blood glucose levels remains a primary concern for individuals with this condition. Among the various dietary modifications recommended for people with diabetes, the use of sugar substitutes has gained significant attention. Artificial sweeteners, sugar alcohols and steviol glycosides—what are the differences?Sugar alcohols, artificial sweeteners and steviol glycosides are not the same, although they are used as sugar substitutes in various food products. As there has been a lot of press regarding the safety of sugar alternatives, it is important to highlight their key differences.Sugar Alcohols1What they are: Sugar alcohols, also known as polyols, are a type of carbohydrate. Despite the name, they do not contain alcohol.Examples: Sorbitol, xylitol, erythritol, maltitol, mannitol.Calories: They contain fewer calories than regular sugar (about 1.5–3 calories/gram compared to 4 calories/gram for sugar).Impact on blood glucose: Sugar alcohols have a lower glycemic index than sugar, so they cause a slower, more gradual rise in blood glucose levels.Usage: Commonly found in sugar-free candies, chewing gums and some baked goods. They can also be used in “diabetic-friendly” products.Side effects: Consuming large amounts can cause digestive issues, such as bloating, gas and diarrhea.Artificial Sweeteners1What they are: Artificial sweeteners are synthetic substances that provide sweetness without the calories of sugar.Examples: Aspartame, sucralose, saccharin, acesulfame potassium (Ace-K).Calories: They are usually calorie-free or have very few calories.Impact on blood glucose: They do not raise blood glucose levels, making them popular in diet drinks and products aimed at people managing diabetes.Usage: Found in diet sodas, sugar-free desserts, and tabletop sweeteners (e.g., Splenda, Equal).Side effects: Some people may experience headaches, digestive issues or other sensitivities, though these are relatively rare.Steviol Glycosides1What they are: Derived from the leaves of the Stevia rebaudiana plant, Stevia is 200–300 times sweeter than sugar.Stevia-based sweeteners, examples: Stevia, Truvia, Krisda, Pure Via.Calories: They are usually calorie-free or have very few calories.Impact on blood glucose: They do not raise blood glucose levels.Usage: Found in tabletop sweeteners and are also added to drinks, breakfast cereals, yogurt, fillings, gum, spreads, baked products and snack foods.Side effects: Some Stevia products contain added sugar alcohols and may cause gastrointestinal symptoms. Stevia is also known to be a vasodilator and should be used with caution in those with chronic low blood pressure and/or those taking blood pressure medications.Benefits and Considerations of Artificial Sweeteners in Diabetes ManagementFor individuals with diabetes, artificial sweeteners offer several potential benefits:Weight managementBy providing sweetness without the calories, artificial sweeteners have been intended to support weight loss or maintenance efforts, which are often critical in managing type 2 diabetes.Although they were originally thought to reduce insulin resistance and obesity, data in animal models and humans suggest that the effects of artificial sweeteners may actually contribute to metabolic syndrome and the obesity epidemic as they lead to decreased satiety, alter glucose homeostasis, and are associated with increased caloric consumption and weight gain.2 Studies have also demonstrated the potential for artificial sweeteners to change the host microbiome and as a result, worsen glycemic control owing to changes in the gut microbiota; however, there is currently no unanimous consensus on this effect due to conflicting studies.3No effect on glycemic controlHuman meta-analyses have reported that artificial sweeteners do not result in weight loss or improved glucose control.4 Artificial sweeteners are included in many sweet foods and were anticipated to be a “sugar” substitute in patients with diabetes.5 However, substituting sugar-sweetened food and beverages with those that have been artificially sweetened may not be as beneficial as once thought.6 There is a general concern that the use of artificial sweeteners may lead to overconsumption of sweet foods and beverages, under the assumption that these are “healthy” or “free” foods. This could inadvertently lead to an increase in caloric intake from other sources.Cardiovascular riskA growing body of evidence suggests that artificial sweeteners in general, but especially sugar alcohols like erythritol, appear to promote or foster an enhanced clotting risk. A 2023 study demonstrated that erythritol is both associated with incident MACE (major adverse cardiovascular event) risk and fosters enhanced thrombosis.7 Another study in 2024 reinforced this finding.8 In 2023, the World Health Organization issued a warning that artificial sweeteners such as aspartame and stevia (which is often blended with erythritol) were linked to a greater risk of type 2 diabetes, cardiovascular disease and death in adults.9 Based on these and other studies, including the use of another sugar alcohol, xylitol,10 people with an increased risk of heart disease or blood clotting should avoid the sugar alternatives erythritol and xylitol entirely.Link to cancerThere has been controversy as to the relationship between artificial sweeteners and cancer over the years. A 2021 meta-analysis of case control studies examining the relationship between the use of artificial sweeteners and cancer found that there is no sufficient evidence to show whether the use of artificial sweeteners increases or decreases the risk of cancer.11 A recent hazard and risk assessment on the use of aspartame by the World Health Organization classified aspartame as possibly carcinogenic to humans (Group 2B, 3rd highest out of 4 classifications) on the basis of limited evidence for cancer in humans (specifically hepatocellular carcinoma).12 More data from large clinical trials are needed to clarify the relationship between artificial sweeteners and cancer. Current evidence suggests that they are safe when consumed within acceptable daily intake (ADI) levels, but more research is needed to fully understand their long-term effects. ADIs for various artificial sweeteners are available at: https://www.diabetes.ca/DiabetesCanadaWebsite/media/Managing-My-Diabetes/Tools%20and%20Resources/sugars-and-sweeteners.pdf?ext=.pdf.Talking with patients about sugar substitutesAs trusted healthcare professionals, pharmacists have an important role in educating patients about the safe use of sugar substitutes. Here are some key points to consider when counselling patients with diabetes:Encourage patients to choose a sugar substitute based on their taste preference, cooking needs, and any specific health conditions (e.g., avoiding aspartame in phenylketonuria).Advise patients to use sugar substitutes in moderation, emphasizing that they are a tool to complement, not replace, a healthy diet. Encourage a focus on whole, nutrient-dense foods.Educate patients on reading food labels, to identify hidden sources of sugar substitutes and to be aware of the quantities consumed in order to avoid exceeding the ADI level.Suggest that patients monitor their blood glucose levels after consuming products with sugar substitutes to understand their personal glycemic response, as individual reactions may vary.Keep abreast of the latest research and guidelines on sugar substitutes, as the landscape of diabetes management is continually evolving.SummaryGiven the mixed evidence on their health effects, there is a clear need for further research to fully elucidate the role of sugar substitutes in metabolic health and their suitability as part of dietary interventions for patients with diabetes.Shelley Diamond is a pharmacist and co-founder of www.diabetescarecommunity.ca, an extensive online resource for Canadians living with diabetes, their families and healthcare professionals.References:Diabetes Canada. Sugars and sweeteners. (accessed September 22, 2024).Pearlman M, Obert J, Casey L. The association between artificial sweeteners and obesity. Curr Gastroenterol Rep 2017;19(12):64.Conz A, Salmona M, Diomede L. Effect of non-nutritive sweeteners on the gut microbiota. Nutrients 2023;15(8):1869.Iizuka K. Is the use of artificial sweeteners beneficial for patients with diabetes mellitus? The advantages and disadvantages of artificial sweeteners. Nutrients 2022;14(21):4446.Evert AB, Dennison M, Gardner CD, et al. Nutrition therapy for adults with diabetes or prediabetes: a consensus report. Diabetes Care 2019;42:731-54.Nichol AD, Holle MJ, An R. Glycemic impact of nonnutritive sweeteners: a systematic review and meta-analysis of randomized controlled trials. Eur J Clin Nutr 2018;72:796-804.Witkowski M, Nemet I, Alamri H, et al. The artificial sweetener erythritol and cardiovascular event risk. Nat Med 2023;29:710-8.Witkowski M, Wilcox J, Province V, et al. Ingestion of the non-nutritive sweetener erythritol, but not glucose, enhances platelet reactivity and thrombosis potential in healthy volunteers – brief report. Arterioscler Thromb Vasc Biol 2024;44(9):2136-41.World Health Organization. Use of non-sugar sweeteners: WHO guideline. May 15, 2023. (accessed September 4, 2024).Witkowski M, Nemet I, Li XS, et al. Xylitol is prothrombotic and associated with cardiovascular risk. Eur Heart J 2024;45:2439-52.Liu L, Zhang P, Wang Y, et al. The relationship between the use of artificial sweeteners and cancer: a meta-analysis of case-control studies. Food Sci Nutr 2021;9:4589-97.World Health Organization. Aspartame hazard and risk assessment results released. July 14, 2023. (accessed September 1, 2024).