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...

Xylitol in a jar with tag

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?

Hand holding cup of 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 12, 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.

Health claims

Healthy smile with teeth
Xylitol, with its low GI value of 12, 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 promising 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 when eaten in excess it may have 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 reports that it has a mild laxative effect, which may, for some people, cause digestive discomfort.

Is it better for you than sugar?

Xylitol and 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 5 July 2019 by Kerry Torrens.

A qualified nutritionist (MBANT), Kerry Torrens is a contributing author to a number of nutritional and cookery publications including BBC Good Food magazine. Kerry is a member of the The Royal Society of Medicine, Complementary and Natural Healthcare Council (CNHC), British Association for Applied Nutrition and Nutritional Therapy (BANT).

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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Laura Ward's picture
Laura Ward
30th Aug, 2019
Any dog owners please note that xylitol is toxic to dogs - even a small amount can be fatal
Malcolm Williams's picture
Malcolm Williams
16th Aug, 2019
I have used Xylitol for about two years using it in tea (my prefered beverage) and coffee. I have had multiple health problems over the lat 30 years (I'm now 65) but for about 2-3 years i have been "glucose intolerant" and needed to find a sweetener that wasn't related to Aspartame which has had poor reviews especially in the USA. Xylitol has been a God-send to me and I now cannot bear to have sugar in my tea. I don't drink fizzy drinks like all the usual carbonated suspects and have a poor tolerance to almost all alcoholic drinks. Xylitol is not sickly sweet and used sparingly (1 level teaspoon in a mug) is ideal for me - but everyone is different! Give it a try and if you only use it in tea or coffee you will loose weight. I lost approx. 4 pounds in 10-12 days and I am not overweight so it just shows that at at a shade under 11st. I dropped to 10st 10lbs without trying.
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!