List of sugars and sugar substitutes

In the article below we want to explain some terms which are often mentioned in ingredients lists. This list is not exhaustive!

Types of sugars

Glucose, dextrose, grape sugar

As glucose makes it easier for the body to absorb fructose, it is considered to be a very good substitute for other types of sugar. But be careful, because too much glucose is not ideal since it influences the blood sugar levels! It is better not to use too much of it and rather to regard it as a stopgap solution! Tip: Add a little glucose to meals where you are unable to verify the fructose level.


Fructose, also known as fruit sugar or levulose, is a simple monosaccharide found in many foods. (High-fructose corn syrup, however, refers to a family of mixtures of varying amounts of fructose and glucose.)


Sucrose is the most commonly used household sugar or table sugar. It is the same thing as granulated sugar (it is also referred to as saccharose; Sucrose is composed of one molecule of fructose and one molecule of glucose).


Lactose is a disaccharide sugar that is found most notably in milk. It is formed from galactose and glucose. Lactose makes up around 2-8% of milk (by weight), although the amount varies among species.

Glucose syrup

Glucose syrup does not always just consist of glucose itself, but also contains a small amount (less than 50%) of fructose. It is normally tolerated in small amounts.

Maltose, malt sugar

Maltose is composed of two molecules of glucose. It thus poses no problem to fructose malabsorbers.


Oligosaccharide (multiple sugar) is an umbrella term for chains of sugar molecules. Most of the time it consists of chains composed of fewer than 10 molecules. This type of sugar is most often not clearly defined. These oligosaccharides are often comprised of fructose (oligofructose). That is why products with this term on the label are often not tolerated!


These are longer chains of sugar molecules (often more than 10 molecules). Not tolerated most of the time!

Sugar alcohols

Maltitol, E965, maltitol syrup

This is a carbohydrate which is difficult to digest. It has a low calorie content. Those suffering from fructose malabsorption should avoid maltitol!

Mannitol, E421

Mannitol is present in higher concentrations in figs, some species of seaweed, black salsify, white mushrooms and shitake mushrooms. Fructose malabsorbers should avoid it!

Xylitol, xylite, E967

Xylitol is also present naturally in foods. Xylitol can be found in the bark of birch trees, but also in foods such as plums. Xylitol is commonly used in chewing gum and confectionary products, on the one hand because of its intense sweetness, and on the other hand because it generates a cooling effect on the tongue - similar to menthol - and it also has a preventative effect on tooth decay. Xylitol is classified as safe for those affected by fructose malabsorption*.

*Xylitol – the exception: normally Xylitol does not cause problems for people with fructose malabsorption! However, it does cause bloating and should therefore be individually tested for the degree of tolerance!

Sorbitol, E420

Sorbitol is present, for example, in rowan berries, apples, sallow thorn (sea buckthorn), plums, and raisins. It blocks the GLUT-5 transporter and should be avoided by people suffering from fructose malabsorption!

Isomalt, E953

Isomalt is a sugar substitute that is hard to digest. It is not only used as a substitute for the sweetness of sugar but also because it is used as a filler. Isomalt cannot be recommended for fructose malabsorption sufferers.

Why are these sugar substitutes being used in the food industry?

The so-called sugar substitutes (sugar alcohols) are being used in order to sweeten foods and to retain moisture levels. Since these substances will not cause blood sugar levels to rise, they tend to be used in ’lite’, diet or diabetic products. In large doses this can lead to diarrhoea, also in “normal” people. Most of these substances are not synthetics; they frequently occur naturally.

Why avoid these substances?

A brief explanation: These substances block the transporter that takes the fructose through the intestinal wall. Since this transporter is dysfunctional or only works partly in people affected by fructose malabsorption, it is essential that any further disruption of the transport mechanism is avoided. If a person affected by fructose malabsorption only ingests sorbite and does not ingest fructose in the same period (within 48 hours!), then this should theoretically not cause any problems. These will only appear if fructose is ingested at the same time. Since this can hardly be avoided in practice, these substances should be avoided as far as possible. Here, too, it is important to note: everyone has to find out for themselves where there personal level of toleration lies.

Sources include:
Kamp, A;  Schäfer, Ch; "Gesund essen, Fruktosearm geniessen" Gräfe und Unzer Verlag, 1. Auflage 2007
Schleip, T; "Fructose-Intoleranz - Wenn fruchtzucker krank macht" Trias Verlag; 2005
Römpp, H; Falbe, J; Regitz, M; "Römpp Lexikon Chemie", 9. Auflage, Thieme Verlag, 1992.


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