New systematic review of clinical trials confirms benefits of low/no calorie sweeteners when compared to sugars
- A new systematic review of controlled clinical trials found that low/no calorie sweetened beverage consumption has a neutral impact on blood glucose and endocrine responses, contrary to effects seen with sugar-sweetened beverages
- The (lack of) impact of low/no calorie sweetened beverages on glycaemic responses was similar to water
- The new study supports the use of low/no calorie sweetened beverages as an alternative replacement strategy for sugar-sweetened beverages
When people drink a sugary beverage, blood glucose and insulin levels rise. In contrast, consuming a low/no calorie sweetened drink has no effect on postprandial glycaemic responses. This has been shown in dozens of studies published over the last four decades, and further confirmed in systematic reviews of available randomised controlled trials (RCTs).1,2,3 However, questions are still raised about sweeteners’ overall impact on endocrine (hormonal) responses, or the potentially different effect that individual sweeteners or blends of sweetness could have, or even about how the pattern of intake (e.g., consumed alone or with other foods) could affect blood glucose control.
The new study by Zhang and colleagues4 sheds light into the above questions by examining the impact of beverages sweetened with single or blends of low/no calorie sweeteners on glucose and endocrine responses. It also compares these effects with the impact of water and of sugar-sweetened beverages.
What did the new study show?
The study by Zhang et al is a systematic review and network meta-analysis of 25 studies containing data from 36 acute feeding trials involving 472 participants.4 As the presence of other nutrients (e.g., carbohydrates) and timing of consumption can independently affect glycaemic responses, three patterns of intakes were analysed: (i) low/no calorie sweetened beverages consumed alone, without other food/beverage, (ii) low/no calorie sweetened beverages consumed together with other food/beverage (i.e. added energy and nutrients as carbohydrates), and (iii) low/no calorie sweetened beverages consumed as a preload prior to other food/ beverage.
The study results showed that, when consumed alone, beverages with either single or blends of low/no calorie sweeteners had no effect on postprandial glucose or insulin levels, or on endocrine responses (i.e., glucagon-like peptide 1 (GLP-1), gastric inhibitory polypeptide (GIP), peptide YY (PYY), ghrelin, leptin, and glucagon). The (lack of) effect was similar to what was found with water consumption, whereas sugar-sweetened beverages increased postprandial glucose, insulin, and incretin responses. Similar outcomes were found when low/no calorie sweetened beverages were consumed together with additional energy (calories) from carbohydrates, or when given as a preload, prior to added energy/ carbohydrates.
Why are these findings important?
The results of this new study strengthen our confidence to the available body of evidence that consistently supports a neutral effect of low/no calorie sweeteners on postprandial glucose, insulin and endocrine responses1-4, similar to water and contrary to effects of sugary beverages. The authors conclude that these findings provide support for low/no calorie sweetened beverages as an alternative replacement strategy for sugar-sweetened versions.
In addition, these findings are based on a comprehensive analysis and synthesis of all available data. To draw evidence-based conclusions in nutrition research, we rely on systematic reviews, such as the study by Zhang et al4, that use explicit methods to comprehensively search, critically appraise, and synthesise all the available literature that address a pre-defined clinical question on a particular topic. Another strength of this study is the use of a network meta-analysis, which provided more precise estimates than single direct or indirect estimates and increased the information size.
Why is this important for people living with diabetes or prediabetes?
Humans’ appetite for sweet taste is innate.5 So, it is only natural that people living with diabetes or prediabetes would also desire to consume something sweet. The new study reassures people with diabetes that, contrary to sugars, low/no calorie sweeteners do not affect glycaemic responses and can therefore be used in food and beverages to provide them with a wider choice of sweet-tasting options with no or fewer sugars so that they do not feel deprived.
Diabetes-related organisations worldwide have issued clinical practice and nutritional guidelines supporting the use of low/no calorie sweeteners in diabetes management. For example, the American Diabetes Association (ADA) reconfirmed in its 2023 update of nutritional recommendations6 that: “The use of non-nutritive sweeteners as a replacement for sugar-sweetened products may reduce overall calorie and carbohydrate intake as long as there is not a compensatory increase in energy intake from other sources. There is evidence that low- and no-calorie sweetened beverages are a viable alternative to water.” The findings of this new study further support these recommendations.