The human body associates sensory cues with metabolic consequences. Exposure to sweet-tasting sugars – even in the absence of ingestion – triggers physiological responses that are associated with carbohydrate digestion, absorption and metabolism. These responses include the release of insulin and incretin hormones, which work to reduce blood glucose. For this reason, non-nutritive sweeteners (NNS) have been posited to trigger similar physiological responses and reduce postprandial blood glucose concentrations. The first part of this review presents a brief overview of sweet taste receptor activation in the oral cavity and gastrointestinal tract and the ensuing physiological responses related to glucose homeostasis. The second part of this review contains a systematic literature review that tested the hypothesis that NNS use improves glucose regulation postprandially. Studies were grouped based on sweet taste receptor stimulation paradigms, including pre-ingestive stimulation, ingestion of NNS alone, co-ingestion of NNS with foods, and using NNS as preloads to influence subsequent blood glucose excursions. In summary, the review found that NNS triggered physiological responses, albeit inconsistently, yet failed to significantly lower blood glucose levels in almost all studies.
This systematic review by Tucker and Tan examined the effects of low calorie sweeteners on acute postprandial glucose homeostasis and confirmed the findings of previous publications showing that low calorie sweeteners have no effect on acute glycaemic control. The review concluded that sweet taste receptor activation from low calorie sweeteners does not play a significant role in acute glucose homeostasis and that, weighing the totality of the evidence, low calorie sweeteners do not affect acute postprandial glucose homeostasis when ingested alone, or when added to energy or carbohydrate-matched foods/ drinks, or when delivered as preloads.
This information is important to health care professionals and the general public in considering the potential benefits of using low calorie sweeteners as a means to reduce sugar intake, without affecting glycemic control.