In the expanding world of sugar substitutes, allulose is a relative newcomer. It may look like regular table sugar (sucrose) and even taste like it (with about 70 percent of its sweetness), but major differences exist between these two white crystals.

Like other sugar substitutes, allulose offers the benefit of a sweet, sugar-like taste without significant calorie intake. However, there are still unanswered questions about the novel sweetener.

Sugar Consumption

Excessive consumption of added sugars is a global problem.

Worldwide, levels of sugar consumption soared to the point that the World Health Organization (WHO) made “a reduced intake of free sugars throughout the lifecourse” a “strong recommendation.”

It’s hard to overstate the magnitude and reach of this problem. Pointing out the association between the overconsumption of free sugars and the incidence of non-communicable diseases such as diabetes, obesity, and dental diseases (which are the leading causes of death worldwide), the WHO “conditionally” recommends bringing the total amount of free sugars consumed daily to below 5 percent of caloric intake. For a 2,000-calorie-per-day diet, this amounts to just 100 calories, or 6 teaspoons—a pittance compared to the 17 teaspoons of added sugar consumed by the average adult.

Despite some reductions in the consumption of sugar-sweetened beverages among certain demographics due to public education programs, trends in U.S. sugar consumption have moved upward over the past decade. It’s no wonder that the market for sugar substitutes—which offer the enjoyment of sugary sweetness without some of the problems associated with conventional sugar—has grown into a more than $7 billion industry as of 2023 and is still on the rise.

Added to the eight sugar substitutes that have U.S. Food and Drug Administration (FDA) approval, allulose has received GRAS (generally recognized as safe) designation by the FDA, and approval for use as a general-purpose sweetener.

Enter the Newcomer

Allulose (D-allulose or D-psicose) is a rare, naturally occurring sugar found in small amounts in certain foods, including figs, raisins, maple syrup, and molasses.

In 1994, Japanese scientist Ken Izumori found a way to use an enzyme to convert fructose into allulose. Since corn-derived fructose is readily available, the commercial production of allulose became possible, and interest in its potential health benefits sparked.

Although allulose doesn’t have several decades of research data behind it like ordinary sugar does, what is available shows promise, in particular for those who are living with Type 2 diabetes or obesity.

Annette Snyder, a registered dietitian with Top Nutrition Coaching, told The Epoch Times: “Allulose has a similar chemical structure as the simple sugar fructose, but small differences in its structure stop the body from using allulose like a simple sugar. Thus, it has much less impact on blood sugars and insulin levels. All told, the calories we do get from allulose are about 10 percent of what we’d get from table sugar (0.4 calories per gram versus 4 calories per gram).”

Potential Benefits

A study by Korean researchers, published in the January 2020 edition of Nutrients, divided 36 mice into four groups, feeding them either a normal diet, a high-fat diet (HFD), an HFD with 5 percent erythritol (a sugar substitute), or an HFD with 5 percent allulose (ALL), over 16 weeks.

At the end of the experimental period, the allulose-supplemented mice had lower body weight and body fat mass than those fed the high-fat or erythritol-supplemented diets. The researchers note that, although the precise mechanisms at play are not clearly understood, “our findings suggest that 5% dietary ALL led to an improvement in HFD-induced obesity by altering the microbiome community.”

While other studies using rodents have also demonstrated the ability of allulose to help produce weight and fat loss, only a small amount of research on human participants has been done. Another study published in Nutrients, examined the effect of low- (4 gram (gm), twice per day) and high-dose (7 gm, twice per day) allulose supplementation over 12 weeks, on 121 overweight or obese Korean participants aged 20–40. The study was double-blind, randomized, and placebo controlled. The placebo group received 0.012 gm of sucralose twice per day.

Compared to the placebo group, both the low-dose and high-dose allulose supplementation groups experienced decreased body fat percentage and body fat mass. The high-dose supplemented group also experienced significant decreases in abdominal and subcutaneous fat areas after 12 weeks when compared with the placebo group, indicating that the effects of allulose may be dose dependent (the anti-obesity effects may depend on the amount of allulose consumed).

Allulose may also offer potential benefits for managing blood glucose levels. A systematic review and meta-analysis published in April 2023 in the peer-reviewed journal PLOS ONE examined the effect on postprandial (post-meal) glucose levels when allulose is consumed with a carbohydrate-containing meal.

Although the number and size of human studies reviewed were small, the authors found that the presence of allulose reduces postprandial glucose levels in healthy people through various mechanisms, including a slower absorption of glucose and a suppression of glycemic responses after the consumption of carbohydrates, without causing hypoglycemia.

Because allulose does not appear to raise blood glucose or insulin levels, it is a potentially useful sugar substitute for those with diabetes or prediabetes. Also, unlike sugar, allulose is not metabolized in the mouth and does not cause tooth decay.

Snyder added: “Those seeking weight loss or better blood sugar control would be best suited for using allulose due to being lower in usable calories and significantly less impact on blood sugar. Those seeking to cut back on their added sugar intake for general health reasons could also benefit.”

Some Unknowns

Despite these encouraging findings and that allulose and allulose-containing foods such as beverages, pastries, and yogurts can now be found in some supermarkets in the United States, lingering questions remain.

Canada and the EU have not yet approved allulose as a food product for their citizens since it is still considered a “novel food ingredient” with limited use in the human food supply.

A 2018 Korean study examining the “Gastrointestinal Tolerance of D-Allulose in Healthy and Young Adults” determined that a maximum single dosage of 0.4 gm allulose per kilogram of body weight did not produce uncomfortable gastrointestinal symptoms in young and healthy Korean adults.

The same study recommended a maximum daily intake of 0.9 gm of allulose per kilogram of body weight. For a 150 lb (68 kg) person, this amounts to 27 gm per single dose, or 61 gm maximum per day. Since one teaspoon of allulose is 4 gm, this amounts to a maximum of approximately 7 teaspoons per dose, or 15 teaspoons total, per day.

If allulose is consumed in amounts exceeding these doses, little is known about the effects on humans aside from an increased risk of diarrhea and other gastrointestinal troubles, but there is some cause for concern.

Laboratory-based in vitro studies have found that certain pathogenic bacteria, in particular Klebsiella pneumonia, can use allulose as a substrate.

The German Federal Institute for Risk Assessment (BfR) evaluated whether the use of allulose as a human food ingredient could pose a health risk and determined that more research is needed before it could be accepted, largely because of the substrate concern.

The BfR report determined that “if humans regularly consume foods which introduce new amounts of Dallulose in the human body, a growth advantage may be expected for allulose utilizers among the species K. pneumoniae in human carriers.”

The report raises questions that still need to be addressed, such as whether regular consumption of allulose causes it to collect in certain areas of the body and whether it negatively affects the occurrence or infectiousness of the Klebsiella bacteria.

While the use of allulose offers potential benefits, especially for those with Type 2 diabetes or obesity, some questions remain about its safety when consumed in large quantities.

Snyder noted, “Allulose is generally safe to use, with the usual caveat ‘in moderation.’”