Sweeteners or sugar substitutes are ingredients used to sweeten and, in some cases, enhance the flavour of foods. Some sweeteners are much sweeter than table sugar, and smaller amounts are needed to achieve the same level of sweetness as sugar in food. People may choose to use sweeteners instead of sugar for various reasons. For example, sweeteners contribute only a few or no calories to the diet and generally will not raise blood sugar levels. Sweeteners are widely used in foods and beverages marketed as "sugar-free" or "diet". Consumers can identify whether a product has a sweetener by looking for the sweetener’s name or E number in the ingredient list on the product label.

Aspartame

The United States Food and Drug Administration (FDA) stated that aspartame, a commonly used sugar substitute, is safe to consume. This was in response to a recent assessment by the World Health Organization (WHO) that raised the possibility of a link between aspartame and liver cancer. The FDA emphasizes that aspartame has been thoroughly studied and its scientists have no safety concerns if it is used under approved conditions. The International Agency for Research on Cancer (IARC), a WHO body, established a possible link between aspartame and one type of liver cancer, hepatocellular carcinoma. Dr. Mary Schubauer-Berigan, an IARC staff member, however, acknowledged that the evidence is limited, and the studies may have some flaws that affected the results. Schubauer-Berigan stressed that further research is needed to determine whether aspartame can actually cause cancer in humans. The FDA spokesperson clarified that the classification of aspartame as “probably carcinogenic to humans” does not mean that there is a proven connection with the development of cancer.

Health Canada and the European Food Safety Authority also deemed aspartame safe at the currently allowed levels. Furthermore, the Joint Expert Committee on Food Additives (JECFA), an international group of scientists from the WHO and the UN, said that the evidence for a link between aspartame and cancer is not convincing. The JECFA continues to recommend a daily intake limit of 40 milligrams per kilogram of body weight. The United States Department of Health and Human Services supports the JECFA’s authority in formulating public health recommendations on the safety of aspartame. They argue that the JECFA reviews both public and private data, while the IARC only considers public data, thus their review is not complete. The FDA proposes a slightly higher recommendation of 50 milligrams per kilogram of body weight for the daily consumption of aspartame. In summary, while the WHO classification raises concern about the possible link between aspartame and cancerous diseases, the FDA, Health Canada and the JECFA maintain that the consumption of aspartame is safe within the approved limits. Further research is needed to clarify the potential risks associated with the use of aspartame.

Erythritol

According to a recent study published in Nature Medicine, there is a correlation between the consumption of erythritol, a calorie-free sweetener, and the risk of heart attack and stroke. Erythritol belongs to the family of sugar alcohols and occurs naturally in certain fruits and vegetables. Small amounts are also synthesized by the body. Sugar alcohols have a chemical structure similar to table sugar but are less sweet. Erythritol, for example, achieves 70% of the sweetness of sugar and is considered zero-calorie. It has no lingering aftertaste, does not spike blood sugar, and has less of a laxative effect than some other sugar alcohols. It is commonly used as a sweetener in various processed foods and beverages.

In the study, researchers analyzed blood samples from 1157 patients and found that those with higher erythritol levels in their plasma had two-fold higher risk for heart attack or stroke. Further experiments revealed that erythritol promotes platelet aggregation and blood clot formation. Increased blood clotting can elevate the risk of heart attack and stroke. However, these findings are observational and do not prove that erythritol directly causes blood clot formation. Additional research is needed to examine the long-term effects of artificial sweeteners. In the meantime, it is advisable to reduce erythritol consumption. Health Canada, along with the U.S. Food and Drug Administration (FDA) and European Food Safety Authority (EFSA), consider sugar alcohol consumption safe, but excessive intake may lead to digestive issues.

Sucralose

Sucralose, a commonly used artificial sweetener, is often found in foods and beverages. However, its effects on the body are not fully understood. According to a new research by the Francis Crick Institute, consuming large amounts of sucralose reduces activation of T cells in subcutaneous cancer mouse models and bacterial infection mouse models. It also results in decreased T cell function in models of T cell-mediated autoimmune. T cells are a type of white blood cell that assists the immune system in fighting diseases. The study suggests that this effect might also suppress the immune response in humans and could potentially be used to treat people with autoimmune disorders, like type 1 diabetes.

It’s important to note that the doses tested were much higher than what people typically consume in their regular diets, and further research is needed to see whether these effects can be reproduced in humans. During the experiment, mice were fed sucralose at levels equivalent to the acceptable daily intake recommended by the European Food Safety Authority (EFSA) and the U.S. Food and Drug Administration (FDA) (15 mg per kilogram of body weight and 5 mg per kilogram of body weight, respectively). The researchers hope their findings can guide personalized dietary advice for individual patients and find elements of our diet that doctors can exploit for treatment. While the results don’t show harmful effects of sucralose for humans, they may lead to the consideration of higher therapeutic doses for patients. Further research is necessary to explore whether there are other cell types or processes that are similarly affected by this sweetener.

According to a recent publication by researchers from the North Carolina State University and the University of North Carolina at Chapel Hill, the sucralose-6-acetate, an intermediate generated during the manufacturing process of sucralose and its breakdown in the intestines, may be genotoxic and can damage DNA. The study, based on in vitro experiments on human blood cells and intestinal epithelial cells, demonstrated that sucralose-6-acetate increases the expression of genes associated with inflammation, oxidative stress, and cancer. Additionally, it enhances the permeability of the intestinal wall. The study's corresponding author expressed concerns about the potential health effects of sucralose and sent her investigation to the European Food Safety Authority (EFSA). Sucralose is a widely used artificial sweetener approved for various food categories in Europe, including carbonated beverages, chewing gum, cereals, sauces, and jams. Its sweetening power is up to 650 times higher than table sugar.

Consumers can easily identify sucralose on product labels by its code “E-955” among food additives. The European Scientific Committee on Human Food established an acceptable daily intake (ADI) for sucralose of 15 mg per kilogram of body weight. However, EFSA is currently reviewing the safety of sucralose and other sweeteners, the re-evaluation is expected to complete in the course of 2024. During this review, new data and scientific knowledge will be considered, which could lead to updates in the ADI or changes to the legislation. In addition to potential risks, sucralose is recognized for its role in maintaining tooth mineralization and reducing glycaemic responses after a meal. Based on the results of the re-evaluation, the European Commission and national authorities will decide whether any necessary restrictions or limitations are needed regarding the currently permitted uses.

Non-sugar sweeteners

The World Health Organization (WHO) has released a new guideline on non-sugar sweeteners (NSS), which do not recommend their use to control body weight or reduce the risk of non-communicable diseases. The recommendation is based on the findings of a review which found no long-term benefits of NSS in reducing body fat in adults or children. The review also indicated potential undesirable effects from long-term use of NSS, such as an increased risk of type 2 diabetes, cardiovascular diseases, and mortality in adults. The WHO Director for Nutrition and Food Safety, emphasized the importance of reducing free sugars intake, such as consuming food with naturally occurring sugars, like fruits, or unsweetened food and beverages. The recommendation applies to everyone except people with pre-existing diabetes and includes all synthetic and naturally occurring or modified non-nutritive sweeteners.

The International Sweeteners Association (ISA) expressed concerns about the guidelines, stating that they should have been based on the comprehensive set of available evidence. ISA believes that the recommendation is not scientifically rigorous and may result in undesirable health outcomes for some individuals. They argue that low/no calorie sweeteners have enabled food and beverage manufacturers to reshape their products and comply with public health recommendations for sugar reduction. ISA also expresses concern over the lack of recognition for the well-established benefits of low/no calorie sweeteners in sugar and calorie reduction. Coherent policies based on rigorous scientific evaluation and higher-quality research are necessary to address the complex challenges of reducing non-communicable diseases. While this guidance does not apply to individuals living with diabetes, it could mislead those who need to regulate their carbohydrate and sugar intake.

Daily intake of sweeteners and levels of sweetness compared to table sugar

Acceptable daily intake (ADI) of sweeteners in the EU and USA are the following:

The levels of sweetness of different sweeteners compared to table sugar are the following: