"Does the Sweetener Allulose Have Side Effects?"
First there was sugar and high fructose corn syrup,
the original industrial sweeteners.
They were cheap, but had lots of empty calories,
and contributed to diseases
such as obesity, type 2 diabetes, cavities, and metabolic syndrome.
So then came the second-generation sweeteners, the artificial sweeteners,
the colored pastel packets: Nutrasweet, Splenda,
Sweet & Low. Practically zero calories,
but adverse effects have been described, cautions have been raised.
For example, artificial sweeteners were found to induce glucose intolerance
by altering the gut microbiome, thereby producing
the counterintuitive effect of inducing metabolic derangements.
They also taste kind of funny.
Enter the third-generation Sweeteners, sugar alcohols,
such as sorbitol, xylitol, and erythritol, low-calorie sweeteners,
however, their laxative effects can create difficulties,
which brings us to rare sugars like allulose, which are
natural sweeteners with low or zero calories and a sugar-like taste.
For those of you who haven't heard of allulose,
it's been through a bit of rebranding.
Just like rapeseed oil morphed into canola, forcing municipalities
to update their town slogans,
allulose used to be called psicose, a sugar you may not want to eat
in the shower.
The name "psicose" is derived from the antibiotic from which
it was isolated --- a strange origin story for a sweetener.
In the Frontiers of Bioengineering and Biotechnology, emphasis
is placed on the fact that allulose is a real and natural sugar
rather than artificial, but ironically if you look at a reference they cite,
it talks about how allulose is made, via functionalized
polyhydroxyalkanoate nano-beads
decorated with D-tagatose 3-epimerase (DTE)
produced in recombinant endotoxin-free branded bacteria.
And now technically allulose is a natural sugar, a so-called rare sugar,
which have been defined by the International Society of Rare Sugars
as sugars that are present in limited quantities in nature.
But recent technological advances, such as enzymatic engineering
using genetically modified microorganisms, now allow
manufacturers to produce otherwise rare sugars
like allulose in substantial quantities.
But small amounts have pre-existed in the food supply,
so the FDA granted it generally recognized as safe status,
but it's been like really small amounts, like a few
dozen milligrams, or a quarter of a quarter of a quarter of a teaspoon.
See, allulose is generated when fructose is heated.
That's why this poor guy kept breaking out in hives
eating such a strange variety of foods, because he happened
to be allergic to allulose, and allulose is created incidentally
in the process by which high fructose corn syrup is made.
So basing the safety of allulose on the fact that it's already been
present in the food supply isn't very convincing.
You don't know if it's safe until you put it to the test.
Unlike table sugar, allulose is safe for the teeth;
isn't apparently metabolized by cavity-causing bacteria
to make acid and build up plaque.
It doesn't raise blood sugars, even in diabetics.
It can be labeled as having zero calories, though technically
it may have like one and a half calories per teaspoon,
similar to what you see with erythritol.
Also like erythritol, it's only about 70% as sweet as table sugar
but has almost the same taste, performance,
and texture as regular sugar.
Are there any toxicities?
Allulose is considered a relatively nontoxic sugar.
What does that mean?
Well, in pets, we know a sweetener called xylitol can
be extremely dangerous to dogs.
As little as a half teaspoon in a 30-pound dog can be life-threatening,
whereas a similar dose of allulose apparently wouldn't be a problem,
though like over half cup at a time could make them sick.
This was a single dose study though.
The long-term safety of allulose was tested over a period
of a few months and didn't seem to cause any harmful effects at a dose
of about one and a half teaspoons a day for healthy 30-pound dogs.
In fact, their cholesterol actually went down,
leading the investigators to suggest clinical studies to see
if it's something vets should start prescribing for overweight pooches.
What about in people?
When the dose of allulose was gradually increased
to identify the maximum single dose for occasional ingestion,
no cases of severe gastrointestinal symptoms were noted
until a dose of 0.4 g/kg of bodyweight was reached,
which could be about 7 teaspoons, with severe symptoms
of diarrhea noted once you get up around 9 teaspoons.
And you say, "who could eat that much sugar at a time anyway?"
A single can of Coke has 10 teaspoons,
and a bottle of Mountain Dew has nearly twice that.
So allulose is clearly not suitable as a standalone sweetener
for sugary beverages.
In terms of the daily upper limit given in smaller doses
throughout the day, once you hit around 17 teaspoons a day,
depending on your weight, people start getting
severe nausea, abdominal pain, headache, diarrhea.
So people should probably stay under single doses
of about 7 teaspoons,
and not exceed around 15 for the whole day.
The average American may be getting 17 teaspoons
of added sugar a day, so it's certainly not something
the food industry can completely switch over to.
In this way, allulose is close to xylitol in terms of
maximal single dose,
whereas the average-weight man in the US could get away with
14 teaspoons of erythritol at a time,
and the average woman, 15 teaspoons.
Still not enough to sweeten a bottle of Coke, but offers
a little more leeway for sweetening tea
or sprinkling on a grapefruit or something.
Allulose is claimed to provide health benefits
though, compared to erythritol.
Forth generation sweeteners like allulose are said to have
as an advantage: additional functions.
We'll find out if that's true, next.