If you're trying to drop some pounds, artificially sweetened foods and drinks can seem like a silver bullet — you get to savor all the sugary sweetness with none of the calories. But if something sounds too good to be true, it usually is. A new study published in the journal Nature found that fake-sweet foods could raise your blood sugar even more than the real deal.
Scientists were so surprised they repeated the study four times, just to be sure. But the results were the same. When mice were given artificially sweetened water or sugar water, those drinking the fake-sweet water had much higher blood sugar levels, regardless of their diet. The scientists gave the mice the equivalent to what humans get in about four cans of soda a day. Use of the artificial sweeteners seemed to change the composition of microorganisms living in the gut.
After the mice were given antibiotics to clear their guts of bacteria, their blood sugar settled back to normal levels.
Then the researchers tested humans. Four hundred people who consumed synthetic sweeteners proved to have different guts from those who did not. They also showed higher blood sugar levels and a precursor for Type 2 diabetes.
According to the researchers, common sweeteners such as saccharin, sucralose and aspartame may increase blood sugar levels by drastically changing the composition of the trillions of microorganisms that reside in our intestines. They are critical to maintaining the immune systems and helping with nutrition absorption.
Why mock sugars are so shocking to stomachs remains unknown. More studies are needed to better understand these findings. In any case, sugar — real or otherwise — is best taken in small doses.
Nature. 2014 Oct 9;514(7521):181-6. doi: 10.1038/nature13793. Epub 2014 Sep 17.