Artificial sweeteners and other sugar substitutes are widely used to reduce added sugar and calories, but their metabolic effects can vary depending on the compound. A newly developed sweet protein called sweelin is being investigated as another potential way to provide intense sweetness with little effect on blood glucose or insulin.
Developed by Israeli biotechnology company Amai Proteins, sweelin is a sweet protein reported to be approximately 3,500 times sweeter than sucrose by weight. Early clinical research suggests that, in healthy adults, a sweelin-sweetened drink produced substantially smaller short-term glucose and insulin responses than a drink containing dextrose.
What makes sweet proteins different
Sweet proteins are naturally occurring proteins found in several tropical plants. Unlike sucrose and other caloric sugars, they can produce an intensely sweet taste in very small quantities.
Sweelin was developed using a naturally occurring sweet protein as a starting point. Amai Proteins uses computational protein design and fermentation-based production to create a version intended to have characteristics suitable for commercial food manufacturing.
Because only small quantities are required to produce sweetness, the ingredient can potentially reduce the amount of added sugar needed in certain foods and beverages.
The company describes sweelin as a water-soluble powder with stability characteristics that allow it to be incorporated into a range of products. Amai has also reported that the ingredient can replace substantial amounts of sugar in some formulations, including certain baked and processed foods.
However, sugar contributes more than sweetness to food. It can affect texture, volume, browning, moisture and other properties, meaning that the amount that can be replaced depends on the formulation rather than on sweetness intensity alone.
A small clinical trial examined metabolic responses
Researchers investigated sweelin in a small double-blind, randomized clinical trial conducted at Tel Aviv Sourasky Medical Center and funded by Amai Proteins.
The study included 19 healthy adults who consumed three differently sweetened beverages on separate occasions.
One beverage contained sweelin, another contained stevia and a third contained dextrose. Dextrose is glucose and therefore provides a useful comparison for assessing the physiological response to a carbohydrate that directly raises blood glucose.
Blood samples were collected over 120 minutes following consumption of each beverage. Researchers measured glucose, insulin and glucagon-like peptide-1, or GLP-1, a gastrointestinal hormone involved in glucose regulation and other physiological responses to food.
The glucose and insulin responses following sweelin were substantially smaller than those following dextrose and were more similar to the responses observed with stevia.
According to the study, the overall glucose response to sweelin was 31 times lower than the response to dextrose, while the insulin response was 81 times lower.
Sweelin also did not produce a detectable increase in GLP-1 under the conditions examined.
What the findings do — and do not — show
The results provide preliminary evidence that sweelin itself produces little acute glucose or insulin response in healthy adults.
That could make sweet proteins interesting as ingredients in products designed to reduce added sugar. However, the findings should not yet be interpreted as evidence that sweelin improves glucose control in people with diabetes or prediabetes.
The 19 participants were healthy adults rather than people with diabetes, prediabetes or obesity. The experiment also followed participants for only two hours after consuming the test beverages.
Consequently, the study cannot establish whether regular sweelin consumption improves HbA1c, insulin sensitivity, body weight or long-term cardiovascular and metabolic outcomes.
The finding involving GLP-1 also requires careful interpretation. A lack of measurable GLP-1 stimulation is not inherently an advantage or disadvantage. GLP-1 has several physiological functions, and the study primarily demonstrates that sweelin did not produce a detectable acute GLP-1 response under the experimental conditions.
Regulatory status in the United States
Sweelin has also progressed through an important US regulatory process.
In 2024, the US Food and Drug Administration responded to a Generally Recognized as Safe, or GRAS, notice concerning the sweet protein and indicated that it had no questions regarding the notifier’s conclusion under the proposed conditions of use.
A “no questions” response to a GRAS notice should not be described as conventional FDA approval of the ingredient. Rather, it means the agency did not question the company’s conclusion that the substance was generally recognized as safe for its specified intended uses based on the information submitted.
This regulatory distinction is important when describing novel food ingredients to consumers.
Why food manufacturers are interested
Sweet proteins are attracting attention partly because food manufacturers are looking for ways to reduce added sugar without sacrificing sweetness.
High consumption of added sugars is associated with adverse cardiometabolic outcomes, and dietary recommendations generally encourage limiting added sugar intake.
An ingredient that provides substantial sweetness at extremely low concentrations could therefore be useful in product reformulation.
However, replacing sugar with a sweet protein does not automatically make a food nutritionally beneficial. The overall nutritional profile still depends on the complete formulation, including calories, saturated fat, fiber, sodium and other ingredients.
Similarly, the metabolic response to sweelin consumed alone in a controlled beverage cannot necessarily predict the physiological response to a complex food containing the ingredient.
Important questions remain
The clinical findings are encouraging but preliminary.
The trial involved only 19 participants, examined acute responses for two hours and was funded by the company developing the ingredient. These factors do not invalidate the results, but they make independent replication particularly important.
Longer studies would be needed to evaluate regular consumption and outcomes involving appetite, body weight, glucose regulation and other aspects of metabolic health.
Research involving people with type 2 diabetes, prediabetes or obesity would also be necessary before claims can be made about potential benefits for these groups.
Questions about long-term gastrointestinal tolerance and other effects of repeated consumption will become increasingly relevant if the ingredient enters a wider range of foods.
The study reporting the acute metabolic responses to sweelin was published in the peer-reviewed journal Food Chemistry. Its results provide an early indication that this intensely sweet protein can deliver sweetness without producing the glucose and insulin response observed with dextrose in healthy participants.
Whether those properties translate into meaningful long-term health advantages remains unknown. Larger independent studies will be needed before sweelin can be considered more than a potentially useful ingredient for reducing sugar in certain foods and beverages.