Nonnutritive sweeteners (NNS) provide a sweet taste similar to sugar with minimal to no caloric content. They are widely used in food and beverage products as an alternative to traditional sugar, allowing consumers to enjoy sweetness without significant caloric intake.
Understanding Nonnutritive Sweeteners
Nonnutritive sweeteners (NNS) are sweetening agents that deliver a higher intensity of sweetness compared to caloric sweeteners like sucrose, while offering little to no calories. Unlike nutritive sweeteners that are metabolized for energy, many NNS pass through the digestive tract largely unchanged. They achieve their sweet taste by binding to sweet-taste receptors, triggering the perception of sweetness even at very low concentrations. Due to their intense sweetness, only small amounts are needed to sweeten products, minimizing caloric contribution. Before they can be used in food products, NNS undergo rigorous evaluation and require approval from regulatory bodies, often receiving “Generally Recognized As Safe” (GRAS) status or approval as food additives.
Exploring Common Nonnutritive Sweeteners
Common nonnutritive sweeteners include:
Aspartame: A synthetic sweetener, approved by the U.S. Food and Drug Administration (FDA) since the 1980s, approximately 200 times sweeter than sugar.
Sucralose: Marketed as Splenda, a chlorinated derivative of sucrose, about 600 times sweeter than sugar; it is not metabolized by the body.
Saccharin: Discovered in 1878, one of the first nonnutritive sweeteners, 200 to 700 times sweeter than sugar.
Acesulfame Potassium (Ace-K): A synthetic sweetener approved in 1988, 130 to 200 times sweeter than sucrose.
Stevia: Derived from the Stevia rebaudiana plant, a natural-derived sweetener containing steviol glycosides, with some compounds like rebaudioside A being over 300 times sweeter than sucrose.
Monk Fruit Extract (Mogrosides): From the monk fruit, a small green melon native to Southeast Asia, 100 to 250 times sweeter than table sugar.
Erythritol: A sugar alcohol, found naturally in some fruits, provides about 70% of sugar’s sweetness with only 10% of the calories.
Reasons for Choosing Nonnutritive Sweeteners
Nonnutritive sweeteners are chosen for several reasons, primarily due to their ability to provide sweetness without adding significant calories. This caloric reduction can support weight management efforts by helping individuals decrease their overall energy intake. Substituting NNS for caloric sweeteners, such as in diet beverages, may contribute to lower weight regain during weight maintenance.
Another significant motivation for their use is blood sugar control. Since NNS typically do not raise blood glucose or insulin levels, they are considered suitable for individuals managing diabetes or those concerned about insulin sensitivity. They offer a sweet option that does not impact carbohydrate intake in the same way as traditional sugars. Nonnutritive sweeteners also offer dental health advantages, as they do not contribute to tooth decay because oral bacteria cannot metabolize them to produce acids that harm tooth enamel. Additionally, for many, the simple preference for a sweet taste without the associated sugar concerns plays a role in their selection.
Evaluating Health Effects and Safety
The health effects and safety of nonnutritive sweeteners are subjects of ongoing scientific investigation and public discussion. Regulatory bodies, such as the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA), evaluate these sweeteners thoroughly before approving their use, considering short- and long-term toxicity, carcinogenicity, and reproductive toxicity studies. They establish an Acceptable Daily Intake (ADI), which is the amount of a substance that can be consumed daily over a lifetime without posing appreciable health risk. For most approved NNS, consumption within these ADI limits is generally considered safe for the general population.
Research on the impact of NNS on weight management has yielded varied results. While some randomized controlled trials suggest that substituting NNS for sugar-sweetened beverages may modestly aid short-term weight loss, particularly when part of broader lifestyle interventions, observational studies have sometimes shown associations between NNS consumption and higher body weight or increased incidence of obesity. The debate continues regarding whether NNS truly facilitate long-term weight loss or if compensatory eating behaviors occur.
Concerns about the influence of NNS on blood glucose levels and the gut microbiome are also areas of active research. Some studies, particularly in preclinical models, propose that NNS might affect glucose responses or alter the gut microbiome composition. However, human studies have shown inconsistent results, with many not detecting significant effects on gut hormones or glucose absorption. For instance, a 2019 review indicated that there is not enough evidence linking noncaloric sweeteners with adverse effects on gut microbiota when consumed within ADI limits.
Regarding cancer concerns, major health organizations like the FDA and EFSA have generally deemed approved NNS safe at Acceptable Daily Intake levels. The World Health Organization (WHO) and the Joint Expert Committee on Food Additives (JECFA) recently assessed aspartame, classifying it as “possibly carcinogenic to humans” (Group 2B) based on limited evidence for liver cancer in humans. However, JECFA reaffirmed the ADI of 40 mg/kg body weight, concluding that the evidence of an association between aspartame consumption and cancer in humans is not convincing at commonly used doses. This highlights the need for more and better studies with longer follow-up periods to fully understand potential long-term effects.