by Jessica Serdikoff
Xylitol is one of those ingredients that you see on a label that makes you feel like you need a degree in chemistry just to go grocery shopping. Ingredient names are starting to seem more and more foreign; food seems less and less like, well, food. It’s really not as scary as it looks though. Xylitol is a polyol – that is, a sugar alcohol, and a naturally occuring one at that (you can tell sugar alcohols by the -ol suffix: sorbitol and malitol are two other examples). You can find xylitol in a lot of plant materials, including fruits and vegetables, and our bodies even produce small amounts of it during normal metabolism.
But what is it doing in our food? Food manufacturers mostly use it as a low-calorie alternative to sugar. Xylitol, like other sugar alcohols, isn’t recognized by our bodies the same way that sugar is, so it’s metabolized more slowly and less of it actually winds up in our bloodstream. This means that our bodies can only glean 2.4 calories per gram of xylitol, compared to the 4 calories per gram gleaned from regular table sugar. It’s just as sweet as sugar, though, so our taste buds aren’t disappointed by the lower calorie content. Another benefit of xylitol is that it isn’t converted in our mouths to acids that can cause tooth decay. That’s why you often see it in chewing gums, mints and other candies – it’s sweet, but said to actually be protective of oral health.
There are, of course, several concerns. It is toxic to dogs, even in small amounts, but has been found to be safe in humans in doses up to 50 grams per day – considering the fact that most foods contain mere milligrams of xylitol per serving, hardly anyone has to worry about this upper limit. It should be noted, though, that some studies have shown an association of long-term (i.e., greater than 3 years) high-dose consumption with tumor formation, and in the short-term even moderate doses can lead to gastrointestinal discomfort in the form of diarrhea and gas. This second downside of xylitol is common for sugar alcohols, and is a direct result of the fact that it isn’t fully broken down and absorbed during digestion. It’s also advised that pregnant women and women who are breastfeeding avoid xylitol, as not enough studies have been done on the safety of consumption among this population.
So what do we do – eat it, or avoid it? For most people, eating the trace amounts of xylitol found in our foods is not a concern. Most experts recommend restricting intake if you experience uncomfortable digestion-related side effects, or if you’re pregnant or nursing. The studies conducted have, admittedly, been small, so as with anything, most professional’s are emphasizing xylitol’s safety in moderation. So go ahead and chew that stick of sugar-free gum; the few milligrams of xylitol are just fine, and might even help prevent those pesky cavities from ruining your next dentist visit.
Have you ever seen xylitol on your food label? What food did you see it in?
Jessica Serdikoff is the chief blogger behind Floptimism, a blog where Jessica shares deliciously inspiring recipes and tales of life as a nutrition student. Follow Floptimism on Facebook and Twitter.