Sugar substitutes - xylitol explained

Low-GI, low-calorie and apparently good for dental health. Is xylitol all it's cracked up to be? Nutritionist Jo Lewin investigates...

Sugar substitutes - xylitol explained

Xylitol is a naturally present substance found in the fibres of many fruits and vegetables and can be made in small amounts by the body. While it can be sourced from carbohydrate molecules (called polysaccharides) in the cell walls of birch and beech trees, rice, oat, wheat and cotton husks, the main source of xylitol for commercial use is corn cobs. Once extracted and processed, you're left with a white, crystalline powder that looks like sugar. It has the same sweetness as sugar and has become a popular sweetner in food and health products.


How can it be used?tea

Xylitol is frequently found in chewing gum and mints and can be used in place of sugar in many bakes and is easily added to tea and coffee. Check the list of ingredients on packets to know if a product contains xylitol. 


Nutritional information

Xylitol has a low GI value of 7, meaning it has little effect on blood sugar levels and insulin. It is therefore seen as a useful alternative for diabetics. It contains only 2.4 calories per gram and is slowly absorbed. It is partly digested by the liver and then travels to the intestinal tract, where it is broken down further.

TeethHealth claims

Xylitol, with its low GI value of 7, is broken down slowly, indicating that it does not cause a spike in blood sugar or insulin levels and may be helpful in reducing sugar cravings.

Xylitol is seen to have significant dental benefits. We know that diet plays a major role in dental health and that too much sugar causes tooth decay and periodontal disease. Eating sugar causes tooth decay by creating a highly acidic condition in the mouth. Acidity strips teeth of enamel, causing them to weaken and making them more vulnerable to attack by bacteria. Ordinarily, saliva bathes the mouth with an alkaline solution that neutralises all acidity, helping the process of digestion. When saliva turns acidic because of too much sugar, bacteria in the mouth have a feeding frenzy, eating away at enamel. Xylitol can help to prevent this by raising the pH to a more alkaline state, inhibiting the growth of bacteria that cause cavities.

Although the general consensus is that xylitol is good for dental health, some opponents claim that it has unfavourable effects on the digestive tract and its ‘natural’ label is misleading. During the extraction process, chemicals are added to produce xylitol and there have been anecdotal reports that it has a mild laxative effect, causing digestive discomfort.

Is it better for you than sugar?sugar

Xylitol may be better for dental health compared to consuming large amounts of sugar, however, it is still a sweetener and as with other sugar alternatives, too much is not recommended. The best way to control dental cavities and sugar cravings is to avoid excess sugar and aim for a balanced diet.  

This article was last reviewed on 25th March 2015 by nutritional therapist Kerry Torrens.

Jo Lewin works as a Community Nutritionist and private consultant. She is a Registered Nutritionist (Public Health) registered with the UKVRN. Visit her website at or follow her on Twitter @nutri_jo.

Whether you're looking for sweet substitutes, sugar-free baking guides or simply want to find out your recommended daily amounts find all the answers in our sugar hub:
All you need to know about sugar

Do you use xylitol as a sugar substitute? Let us know below if you prefer it to table sugar or whether you've seen any unwanted side effects...

Comments, questions and tips

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11th Dec, 2014
Why dont you reply to me Jo!?!?!? You are the only thing that is sustaining my life. I feed off of your life force. I want to marry you.
2nd Dec, 2014
Great article Jo! I LOVE reading your articles!!!
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13th Jan, 2019
Definitely worth mentioning that xylitol can be deathly poisonous to dogs, so if you're going to use it, make sure your pet can't steal the result!