Some people cannot digest fructose (fructose) and therefore get complaints such as burping, abdominal pain, diarrhoea, nausea and flatulence, but also mood deterioration and listlessness. In addition, undigested lactose binds tryptophan to itself and prevents its absorption. Since tryptophan is the raw material for the messenger substance serotonin and the sleep hormone melatonin, lactose intolerance can increase depression, pain sensations and sleep disorders. New research has shown that larger amounts of fructose can promote insulin resistance and thus diabetes mellitus. Fructose is therefore not suitable for sweetening diabetic products!
Fructose is mainly found in fruit and fruit juices. Since especially pure fructose is poorly absorbed from the intestines in large amounts, these symptoms usually improve if you avoid foods that are very rich in fructose or only consume small amounts. Some people often instinctively develop an aversion to very fructose-rich foods.
If fructose is absorbed in small amounts and in combination with glucose (=dextrose), the absorption from the intestine usually improves and fewer complaints occur. Sorbitol (E420), on the other hand, which is contained in certain types of fruit, diabetic products and some sugar-free sweets (sugar, chewing gum), worsens absorption and thus worsens the symptoms. Sugar additives such as mannitol (E421), isomalt (E953) or xylitol (E967), maltitol (E965) which are contained in chewing gum or sugar have a similarly unfavourable effect as sorbitol. Multiple fructose such as oligiofructose and inulin have also recently been found more frequently in probiotic foods such as yoghurts.
Nutrition for fructose intolerance
Try to completely remove fructose-containing foods such as fruit, fruit juices and fructose-containing finished products from your diet for about 2 weeks. Depending on your individual fructose tolerance, you can then carefully test whether or how much fructose your body tolerates without complaints.

The decisive factor is always the amount of fructose added and whether sorbitol (-> deterioration) or dextrose (-> improvement of symptoms) is added at the same time. For the same reason, diabetic products should be avoided at all (usually contain fructose or sorbitol). For sweetening, pigeon sugar (e.g. in compote) or a mixture of dextrose and normal sugar (dextrose is available as Dextropur in normal grocery stores) is best. Less sensitive people can also tolerate normal household sugar alone without any problems.

Concentrated fruit products such as dried fruit and fruit juices (including must) as well as honey and various types of pomaceous and stone fruit (sorbitol content!) remain particularly poorly tolerated, so that they must be avoided in the long term.
very low fructose
(well tolerated)

  • Banana
  • Honey melon
  • Mandarin
  • Lemon
  • Sugar melon
containing fructose
(individually differently tolerated)

  • Pineapple
  • Artichoke
  • Blackberry
  • Blueberry
  • Kaki
  • Cherry
  • Kiwi
  • Mango
  • Mirabelle
  • Orange
  • Cranberry
  • Rhubarb
  • Black salsify
  • Gooseberry
  • Water melon
  • Onion
fructose and sorbitol containing
(almost always poorly tolerated)

  • Apple
  • Pear
  • Date
  • Strawberry
  • Raspberry
  • Honey
  • Currantt
  • Apricot
  • Peach
  • Plum
  • Raisins
  • Grapes