Monday, June 14, 2010

Xylitol: Healthy Like Sugar Isn’t

Xylitol is a sugar alcohol that is naturally occurring in the human body and is found in many plants.  It was originally made for birch but is mostly extracted from corn today.  Its taste, color and cooking properties are very similar to cane sugar … but that’s where the comparison ends.  In terms of health, xylitol is almost exactly the opposite of sugar and other fructose sources.

Xylitol is a prebiotic that is fermented in the gut creating short chain fatty acids (SCFA) which encourage the growth of good micro-organisms … but sugar and other fructose sources encourage the growth of harmful bacteria and yeasts seriously disturbing gut ecology.

Xylitol is anti-inflammatory … but sugar and other fructose sources are strongly pro-inflammatory.

Xylitol, in some studies, was shown to improve fasting blood glucose levels and post prandial blood glucose levels … but sugar and other fructose sources induce insulin resistance and worsen blood glucose levels.

As little as 7.5 grams of xylitol induced a satiety effect measured at about a 5-8% reduction in calories consumed in one study  … but sugar and other fructose sources impair leptin hormonal signaling resulting in increased hunger and weight gain.

Xylitol improves lipid profile resulting in lower triglycerides, higher HDL and lower LDL … but sugar and other fructose sources are turned directly into triglycerides in the liver and worsen the lipid profile.

Xylitol chewing gum is known to prevent tooth decay … but sugar and other fructose sources cause cavities.

Xylitol’s prebiotic function will improve immune function in general and xylitol gum is also known to prevent ear infections … but sugar and other fructose sources can impair immune function.

Xylitol prevents yeast infections … but sugar and other fructose sources encourage the overgrowth of Candida yeast in the intestine, urinary tract and vagina.

Xylitol helps heal an inflamed intestinal lining … but sugar and other fructose sources can destroy the delicate hair-like villi that line the intestine and contribute to a leaky gut.

Xylitol has 40% less calories than sugar and a much lower Glycemic Index.

Xylitol has a clean sweet taste … but sugar and other fructose sources have a sticky sickening sweet taste.

Is xylitol the perfect sugar substitute?  Well, maybe not perfect, but I believe it to be the best.  Xylitol’s main shortcoming is that some people develop diarrhea and flatulence when they eat too much.  Examined closely, this apparent shortcoming is revealing.  People who suffer ill effects from xylitol probably have unbalanced gut flora which are not able to digest it.  As people who have problems with xylitol gradually increase consumption, the community of micro-organisms in their gut adapts to be able to digest it.  In doing this, one’s gut flora greatly improves in other health promoting ways.

The great majority of people who are new to xylitol can eat up to 25 grams (1 ounce) with no ill effects.  In one study, participants were given a very large dose of 400 grams a day (almost a pound) of xylitol and more than half of the participants reported no ill effects.  The main ill effect reported was flatulence and a smaller number reported diarrhea.

While xylitol has been shown to be absolutely safe and generally healthy for both adults and children, the same cannot be said for all animals.  Xylitol is toxic to dogs.  This may be serious problem for people who share food with their pets.  You cannot give pets any food containing xylitol.

I do not have a dog in my 15th floor apartment, but even if I did, I would not feed it my food.  And, like the majority of people, I have no GI issues with xylitol.  I have always loved the fresh, natural taste of xylitol compared to some of the odd tasting artificial sweeteners, but I only recently came to understand the prebiotic effects of xylitol.  So, for me and most people, maybe xylitol really is the perfect sweetener.
Xylitol    100% Pure Xylitol   Xyli Pure Xylitol   
Where I live in China, xylitol is the most common sugar substitute and is used by almost all diabetics.  It costs about $4.00/lb.  I note that in the US, it can be purchased online at Swanson Health Products for about $5-9.00/lb.

If you have not tried it, I encourage you to experiment to see if it is for you.


  1. I like it very much, unlike so many other sweeteners. Thanks for this very complete report on xylitol! I've made cookies with it, and plan to continue baking experiments. No ill effects here!


  2. Xylitol has a glycemic index of 13 and it will effect the blood sugar of diabetics.

  3. Yes, Michael, xylitol has a glycemic index of 13 which is quite low. According to the South Beach Diet GI chart, cauliflower and celery have a GI of 15. I believe the impact of BG is negligible in most people.

    We are all different and diabetics who are know to xylitol should check their post prandial BG after they consume xylitol to see if it affects them. I have not noticed any appreciable effect. How does xylitol affect your BG?

  4. It's been awhile since I messed with xylitol but it did raise my blood sugar like most sugar alcohols. The only one that doesn't is erythritol.

  5. Xylitol has 40% less calories than sugar and a much lower Glycemic Index.

    Denny, doesn't it mean that it provides 60% of calories that the same weight of sugar can provide? I think those calories do not come from fat or protein and hence have to come from carbohydrates. This means that the carbohydrate content of xylitol is 60% of the same weight of sugar. This is not an insignificant amount of carbohydrates - in many situations the absolute net carb amount is really more important than the GI number. In short, it appears from the calorie value that Xylitol can (i.e., it has the potential to) raise the BG level as it contains not an insignificant amount of carbs. I think the carb content of splenda etc. is practically insignificant.

    I plan to buy Xylitol from a health food store here that carries it and experiment with it.


  6. Rad,

    Yes, xylitol has calories, but it is not metabolized quickly like glucose and does not have any of the ill effects of fructose. I have read some people say that sugar alcohols in general spike their BG. I can certainly see how maltitol with its relatively high GI could do that, but I do not understand how xylitol eaten in moderate quantities could spike one's BG.

    The reason xylitol is a prebiotic is that some beneficial bacteria in the gut ferment part of it into short chain fatty acids (SCFA), principally butyric acid which is known to reduce inflammation, improve lipid profile, lower blood pressure and prevent colon cancer and some other diseases. It does have calories but it is not a fast metabolizing carbohydrate. One of the simplest ways to assess gut health is to measure the amount of butyrate in fecal mass. The more butyrate, the healthier the gut ecology.

    Anyway, Rad, please let us know how you react to xylitol if you try it.

    Should there be any biochemists reading this, would truly appreciate a better, more informed explanation of how the human body metabolizes xylitol.

  7. sadly xylitol even spry toothpaste of which xylitol is one of the first ingredients raises my BG a LOT.

    1. If I recall correctly, sorbitol is used in a lot of oral care products and that's what causes the sugar spike.

  8. I'm a fan of xylitol. We brush our teeth with it!

    Do you have some references for the claims you make? I am particularly interested in the info on lipids.


  9. Xylitol is a natural, intermediate product which regularly occurs in the glucose metabolism of man and other animals, as well as in the metabolism of several plants and micro-organisms. Xylitol is produced naturally in our bodies; in fact, we make up to 15 grams daily during normal metabolism.

    About one-third of the xylitol that is consumed is absorbed in the liver. The other two-thirds travels to the intestinal tract, where it is broken down by gut bacteria into short-chain fatty acids.

  10. I think those calories do not come from fat or protein and hence have to come from carbohydrates. This means that the carbohydrate content of xylitol is 60% of the same weight of sugar.
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  11. My wife has made holiday pies of various sorts with xylitol and served them to our guests. It worked very well and the taste was un-noticeably different than with sugar. I have used it in cookies before and they never seemed to go stale even after sitting around for months (it was an experiment.) I suspect the alcohol part of the molecule acted as a preservative. The only difference in taste that I noticed was the cooling effect that xylitol produces and that was probably because I used too much xylitol.