Allulose: A natural sweetener that lowers glucose levels?

Allulose is a rarer form of sugar first identified in wheat leaves in the 1940s. Since then it remained seldom used and under-researched.

That was until the 1990s, when Ken Izumori, a professor in the Faculty of Agriculture at Kagawa University, Japan, came along. Izumori discovered a microorganism in soil near the university that converted fructose into allulose, with the help of an enzyme.

It's taken another 20-30 years of research, but allulose is now slowly gaining popularity as a sweetener, or alternative to sugar, in the US and South Korea, where it has been approved for commercial use.

Allulose (also known as D-allulose and D-psicose) is still described as rare because it is found in only small quantities in figs, raisins, kiwis, wheat, maple syrup and molasses.

It's said to be about 70% as sweet as conventional sugar (sucrose) but has only 10% of the calories. In fact, you might see it advertised as calorie-free, good for weight-management, or beneficial for people with type 2 diabetes.

Are the claims supported by scientific evidence? We take a look.

Is allulose a zero-calorie sweetener?

The US regulatory body Food and Drug Administration (FDA) has approved the use of allulose in foods as "generally recognized as safe."

But the European Union, Canada and other countries consider allulose as a novel food that has yet to be sufficiently assessed for its safety.

That's why scientists are still assessing the effects of allulose on our bodies.

Recent studies show that the body does absorb allulose, but it does not metabolize it, meaning it could well be glucose- and calorie-free.

In other words, the body does not recognize that allulose contains energy in the form of calories and is, therefore, "tricked" into excreting the majority of the calories.

This may make allulose useful for people who want to lose weight but who still want to enjoy an occasional sweet treat. It's the same reason why allulose could also be useful for those on a ketogenic diet too — a diet with as little carbohydrate as possible (sugar is a carbohydrate).

There is also evidence that allulose does not cause tooth decay, like sugar does.

Glycemic index: How does allulose compare to sugar?

There are also claims that allulose does not raise blood sugar levels.

The glycemic index (GI) ranks foods based on how quickly they are digested and increase blood glucose levels.

Pure sugar raises blood glucose levels by 65 on a scale from 0 to 100.

White bread has a GI of 100 — it takes a long time to digest white bread, and it raises blood glucose levels greatly.

However, evidence shows that allulose does not raise blood glucose levels at all.

Is allulose good for people at risk of type 2 diabetes?

Because allulose seems to have little or no impact on blood glucose, it could be an ideal sugar alternative for people with, or at risk of, type 2 diabetes.

Studies have found that even high doses of allulose did not cause glucose levels to fluctuate in people with diabetes or healthy people.

Some studies have found that eating allulose reduces glucose and insulin levels in people after meals, as well as decreasing the amount of glucose and insulin fluctuation in the blood.

This may be good news for people with diabetes, who have less effective insulin systems and can't regulate blood sugar levels effectively.

However, more evidence from larger clinical trial-type studies are needed back up the claim that allulose is beneficial for people with diabetes.

Does natural always mean healthy?

Allulose does not have a strong aftertaste, meaning it's a useful sweetener for commercial foods like chocolate.

"We lowered the calories [in our chocolate] by up to 40% by replacing sugar with something that is almost calorie-free," said Michelle Oten, founder of GOALZ, a company that only uses allulose to sweeten their products.

Oten said they wanted "something that's found in nature, not created in a lab by playing with molecules." But allulose's label of it being natural and healthy may be deceptive.

For example, there are indications that consuming large amounts of allulose may cause stomachache, diarrhea, bloating, or gas.

Table sugar is natural, just like allulose. It comes from sugar beet or sugar cane plants. In fact, it's possible to make allulose from fructose (fruit sugar) by changing its chemical form with enzymes.

The list of health concerns from eating sugar are long. To name just a few: Diabetes, heart disease, depression, tooth decay, bad skin, cancer. Natural isn't always healthy, then.

What about allulose as an alternative to sugar? Many regulators say it's not harmful to eat, especially compared to sugar. But more studies are needed to know whether allulose has a beneficial impact on health.

This article was written by Lilia Breytenbach during an internship in the DW science department, with support from Zulfikar Abbany and Fred Schwaller.

Sources:

Effects of D-allulose on glucose tolerance and insulin response to a standard oral sucrose load: Results of a prospective, randomized, crossover study, published by Franchi, F., et al. in the journal BMJ Open Diabetes Research & Care (2021) https://doi.org/10.1136/bmjdrc-2020-001939

Allulose in human diet: the knowns and the unknowns, published by Daniel H., Hauner H., Hornef M., Clavel T. in the British Journal of Nutrition (2022). doi: 10.1017/S0007114521003172.