What are the drawbacks of allulose?

December 23, 2025 •

4 min read

According to research, high consumption of allulose can trigger gastrointestinal distress in some individuals, leading to bloating, gas, and diarrhea. This potential for digestive issues is one of several notable drawbacks of allulose, a low-calorie rare sugar that has gained popularity as a sugar substitute.

Quick Summary

Allulose's downsides include potential dose-dependent gastrointestinal issues such as bloating and diarrhea, a high market price, and a limited body of long-term human safety research. Individual tolerance varies, and starting with small amounts is recommended to minimize digestive discomfort.

Key Points

Gastrointestinal Issues: High doses of allulose can cause dose-dependent side effects like bloating, gas, and diarrhea due to poor absorption in the small intestine.
High Cost: Allulose is more expensive to produce than many other sweeteners, making it a pricier option for consumers, especially for regular use or baking.
Limited Long-Term Research: As a relatively new commercial sweetener, there is insufficient long-term human research to fully understand its health effects over many years.
Varying Tolerance: Individual tolerance to allulose varies; those with sensitive digestive systems, like IBS, may be more prone to discomfort.
Culinary Adjustments: It is about 70% as sweet as sugar and browns faster during baking, requiring adjustments to recipes to achieve the desired result.
Uncertain Metabolic Effects: While it has minimal impact on blood sugar, limited studies have raised theoretical concerns about potential metabolic changes at high doses, warranting further research.
Regional Approval: Allulose is approved in the US but not in some other major regions like Europe and Canada, which consider it a 'novel food' still under review.

Allulose: A Closer Look at the Downsides

Allulose, a naturally occurring rare sugar, has been praised for its low-calorie content and minimal impact on blood sugar, making it a popular choice for those on ketogenic diets or managing diabetes. However, like any sugar alternative, it is not without its drawbacks. The most common concerns revolve around its potential for causing gastrointestinal distress, its high price point, and the relative scarcity of long-term human studies confirming its widespread safety.

Gastrointestinal Side Effects and Intolerance

The most frequently reported drawback of allulose is its potential to cause digestive discomfort, especially when consumed in large quantities. This is because the body absorbs allulose differently from regular sugar. While some is absorbed in the small intestine, a significant portion passes into the large intestine largely unmetabolized. This process can lead to a number of unpleasant symptoms in susceptible individuals.

Bloating and Gas: The unabsorbed portion of allulose can undergo fermentation by gut bacteria in the large intestine. This fermentation process can lead to the production of gas, resulting in bloating and discomfort.
Diarrhea and Abdominal Pain: Consuming excessive amounts of allulose can draw water into the large intestine, causing loose stools and diarrhea. Studies have shown that these effects are dose-dependent, with symptoms becoming more severe at higher intake levels.
Nausea: In some cases, particularly with high daily intake, allulose consumption has been linked to feelings of nausea.
Varying Tolerance: An individual's tolerance for allulose can vary significantly. Factors like pre-existing digestive sensitivities, such as Irritable Bowel Syndrome (IBS), may increase the likelihood of adverse reactions. For this reason, experts recommend starting with small doses to assess personal tolerance.

High Cost and Availability

Despite its growing popularity, allulose remains a relatively expensive sweetener compared to table sugar and even other low-calorie alternatives. This is due in part to the commercial production process, which is more complex than refining table sugar. The cost can be a significant barrier for those who want to use it regularly, especially in larger quantities for baking. While prices can vary by brand and location, allulose is consistently one of the more expensive options on the market.

Limited Long-Term Human Research

Another important consideration is the lack of extensive, long-term human studies regarding allulose's effects. While the U.S. Food and Drug Administration (FDA) has given allulose a "Generally Recognized as Safe" (GRAS) status, this determination is based on the current available data. Other regions, like Canada and Europe, still classify allulose as a "novel food" and require more testing before broad approval.

Potential Metabolic Effects: Some animal and cell studies have raised theoretical concerns about potential metabolic side effects, such as decreased HDL cholesterol and increased inflammatory markers at high doses. However, the clinical significance in humans is not yet clear and requires more investigation.
Gut Microbiome Concerns: Though some studies suggest allulose may be beneficial for gut bacteria, others raise concerns that it could potentially promote the growth of certain opportunistic pathogens under specific conditions. More human research is necessary to fully understand the long-term impact on the gut microbiome.

Allulose vs. Other Sweeteners: A Comparison of Drawbacks

To understand the tradeoffs of choosing allulose, it is helpful to compare its drawbacks against other popular sweeteners. The following table highlights some key differences in their potential negative effects.


Feature	Allulose	Erythritol	Monk Fruit	Stevia
Gastrointestinal Issues	Dose-dependent; bloating, gas, diarrhea, abdominal pain, especially in large doses.	Can cause GI issues in some people, but generally better tolerated at moderate doses than other sugar alcohols.	Often blended with sugar alcohols (like erythritol), which can cause GI discomfort.	Pure stevia has minimal GI effects; blends may contain other ingredients that cause discomfort.
Aftertaste	Minimal to no aftertaste; flavor is considered very sugar-like.	May have a slight cooling effect in the mouth.	Can have a bitter or licorice-like aftertaste, especially in high concentrations.	Can have a distinct, bitter aftertaste for some people.
Cost	Considered relatively expensive compared to many other sweeteners.	Moderately priced, often more cost-effective than allulose for baking.	Varies widely; pure extract is expensive, but diluted forms are more affordable.	Tends to be more expensive per serving due to concentrated sweetness.
Research Limitations	Relatively new to the market; limited long-term human studies.	Long-standing history, but recent studies have raised concerns about links to cardiovascular events.	Less long-term research compared to more established sweeteners.	Widely studied and considered a safe choice.

Culinary Challenges

While allulose is celebrated for its performance in baking, it does present some culinary challenges. It is only about 70% as sweet as sugar, meaning you may need to use more of it to achieve the desired sweetness, which can exacerbate the risk of digestive issues. Additionally, allulose tends to brown more quickly than regular sugar, necessitating adjustments to baking temperatures or times to prevent scorching. For specific recipes, particularly frozen desserts, its properties can be a benefit by preventing icy crystallization, but this variability can be a learning curve for some home cooks.

Conclusion

In conclusion, while allulose offers compelling benefits as a low-calorie, non-glycemic sweetener, it is not a perfect sugar replacement for everyone. Its primary drawbacks are the potential for significant dose-dependent gastrointestinal side effects, its high market price, and the current limitations in long-term human research. Individuals considering allulose should start with small quantities to assess their personal tolerance, be mindful of the cost, and recognize that more data is needed to fully understand its long-term health implications. Moderation remains key, and consulting a healthcare professional is always advisable when making significant dietary changes, especially for those with pre-existing conditions or sensitive digestive systems.

To learn more about the metabolic properties of allulose, including studies on its effect on glucose and insulin, visit the National Institutes of Health (NIH) website.

Frequently Asked Questions

Yes, allulose can cause bloating, especially when consumed in high amounts. The unabsorbed rare sugar can ferment in the large intestine, leading to the production of gas and causing a bloated feeling.

Yes, allulose is significantly more expensive than regular table sugar. It is also often pricier than other popular low-calorie sweeteners due to its commercial production process.

Individual tolerance varies, but many people find allulose to be better tolerated in moderate doses compared to some sugar alcohols like erythritol. However, excessive consumption of both can cause digestive distress.

Allulose is not approved for general use in Europe because regulatory bodies, such as the European Food Safety Authority (EFSA), classify it as a "novel food." They require more testing and long-term data before it can be widely introduced into the food supply.

Individuals with sensitive digestive systems, including those with conditions like IBS, should approach allulose with caution. Starting with small amounts is recommended, as they may be more susceptible to gastrointestinal discomfort.

The long-term health effects of allulose are not yet fully understood due to a lack of extensive long-term human studies. While initial safety data is promising for moderate consumption, more research is needed to determine the effects of long-term, high-dose intake.

Allulose causes digestive problems because it is not fully absorbed by the body. The unabsorbed portion travels to the large intestine, where it can be fermented by gut bacteria, leading to gas and bloating. It can also draw water into the gut, causing a laxative effect.