Overview
About Tagatose
Tagatose is a rare sugar, a ketose isomer of galactose that occurs naturally in tiny amounts in dairy and some fruits and is manufactured from lactose for commercial use.
It tastes close to sucrose, around ninety per cent as sweet with a very similar mouthfeel and no cooling effect, and it browns properly in baking, which sets it apart from most sugar replacements. The trade off is what happens after you swallow it: most of a tagatose dose is not absorbed in the small intestine and passes to the colon to be fermented, which is why it grades as a genuine fermentable load rather than an inert sweetener.
Sensitivities
How Tagatose scores
Watch for
What trips people up
- Graded moderate on FODMAPs and on SIBO fermentation, and unlike most sweetener grades that is mechanistic rather than precautionary. The unabsorbed fraction really is fermented in the colon, producing gas and, at higher doses, osmotic loosening.
- It is not the same as allulose, though the two are often shelved together as rare sugars. Allulose is absorbed in the small intestine and then excreted in urine largely unchanged, so it is much gentler on the gut. Tagatose is not absorbed and ferments. If you tolerate allulose, do not assume tagatose behaves the same way.
- It is manufactured from lactose, which is worth knowing for anyone avoiding dairy for allergy rather than for lactose. The finished product is a purified monosaccharide with no milk protein, but the origin is dairy.
- Dose escalates the effect sharply. Small amounts in a formulated product are usually unremarkable; using it spoon for spoon in place of sugar in a home recipe is a much larger load.
- It has a genuine prebiotic effect, which is a benefit or a problem depending entirely on whether you have SIBO.
Diet fit
Where it fits
Swap ideas
More alternatives
FAQ
Common questions about Tagatose
Is tagatose the same as allulose?
No, and the difference is the most practical thing on this page. Both are rare sugars that taste close to sucrose with few calories, so they get shelved together, but they behave completely differently once swallowed. Allulose is absorbed in the small intestine and then excreted in the urine largely unchanged, which is why it is comparatively gentle on the gut. Tagatose is mostly not absorbed and travels to the colon, where bacteria ferment it. That is why tagatose carries a real FODMAP grade and allulose does not. Tolerating one tells you nothing about the other.
Does tagatose cause bloating?
It can, and the mechanism is straightforward. The majority of a tagatose dose is not absorbed in the small intestine, so it arrives in the colon intact and is fermented by gut bacteria, producing gas. At higher doses the unabsorbed sugar also draws water into the bowel, which loosens stool. This is the same general behaviour as a polyol like sorbitol, even though tagatose is not a polyol. Small amounts in a commercial product are usually fine; substituting it cup for cup for sugar in home baking is where people run into trouble.
Is tagatose suitable for diabetics or vegans?
It has a low glycaemic impact, because the small absorbed fraction is metabolised in the liver by a route that does not raise blood glucose much, which is the basis for its use in low glycaemic products. Anyone managing diabetes should still treat that as a reason to test rather than to assume. On the vegan question the answer is less clean than most sweeteners: commercial tagatose is manufactured from lactose, a milk sugar, so although the finished product contains no milk protein, its origin is dairy and strict vegans may want to check with the manufacturer.
References
Read the background
Ratings reflect the Triggerbites ingredient database and may vary with portion size and preparation.