While there are many types of sugar substitutes out there, this post will focus on the sugar alcohols. First, what are sugar alcohols? Molecularly, sugar alcohols are sugars (glucose, fructose, etc.) that have their double-bonded oxygen hydrogenated. If you can’t picture that, it’s okay, here’s what it looks like: =O becomes -OH
While this may not seem like a significant change to us, it makes quite a difference in the sweetness and the fermentability of the sugar. After the hydrogenation, sugar alcohols are less sweet and incapable of being fermented by the bacteria in your mouth, not to mention they don’t produce as much energy as regular sugar (aka: they’re lower in calories). For diabetics, sugar alcohols and the ketogenic diet are recommended to prevent spikes in blood sugar. Lots of perks to replacing sugar with sugar alcohols!
Now the downsides. The problem with not being real sugar is that these substitutes don’t react like sugar. Sugar alcohols don’t brown, so you can forget about that delicious crème brûlée or making caramel with it. The Maillard reaction, responsible for producing the delicious odor of baked goods only occurs between sugars and proteins. Sugar alcohols do not partake in the Maillard reaction. Sorry, but that amazing smell is 95% of the reason I get lured into bakeries. Plus, if we all switched to sugar alcohols in baking, I’m pretty sure it would single-handedly destroy the French pâtisserie and boulangerie business.
Not all sugar alcohols go through our digestive system the same way. While all are absorbed slowly (slower than regular sugar, at least), they are subject to fermentation by bacteria in our large intestine. This means lots of gas and possibly even diarrhea if you eat too much of the sugar alcohol. Maltitol is known to do this (see Amazon reviews for Haribo sugarless gummy bears) and xylitol can, but usually isn’t consumed in large enough quantities.
Erythritol is an up-and-coming sugar alcohol and you’ve probably heard or read lots of articles about. Similar to xylitol, erythritol cannot be used for energy by the bacteria in our mouths, therefore it doesn’t cause enamel degradation (cavities). Most of it is absorbed before reaching the large intestine, so no gas or diarrhea. In the bloodstream, it isn’t used by any cells for cellular respiration and eventually you just pee it out. I’ve seen someone eat 2 pints of Halo Top Ice Cream (in under 20 minutes) and be perfectly fine. He had a craving.
Next time you’re contemplating sugarless treats, be sure to look at the ingredients to see which type of sugar alcohol you’re consuming. From there, you can either give yourself a limit or go nuts. Personally, I prefer real sugar, in moderation.