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Fructose, Lactose & Histamine


On this free to use website, you can find useful information about lactose intolerance, fructose malabsorption, histamine intolerance, gluten intolerance or coeliac disease, and much more. The information provided is subject to stringent quality criteria.

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Can fructose malabsorption cause depression?

The answer is: Yes, it can!

This happens on two levels. If the food intolerance is not treated and more fructose is ingested, then the person will experience the symptoms described elsewhere (see “Symptoms of fructose malabsorption”). In the long run these symptoms will lead to the deterioration of the psychological and social situation.

But there is also a biochemical cause that can make fructose malabsorption responsible for depression.

iStock_depressionSerotonin (frequently called the "happy hormone") has a diverse array of tasks. One of them is to act as a neurotransmitter which is responsible for us feeling "happy". Serotonin is produced from tryptophan, an essential amino acid. Essential means that the body cannot synthesise this amino acid by itself but needs to supply it from ingested food. Tryptophan will form a stable complex with the fructose in the gut and thus cannot be absorbed by the body when a high concentration of fructose is present. Because of this many people with fructose malabsorption have insufficient tryptophan and thus also too little serotonin. The result will be, amongst other problems, a state of depression.

The disastrous consequences: The body knows that it needs the tryptophan, and the person tends to eat more foods that will contain this substance. However, nearly all these foods tend to have a very high fructose content. In addition, we are often told that we should eat more fruit because it is healthy and it helps. But it doesn't help at all. Instead, if a person is suffering from fructose intolerance, it just makes the whole situation much worse.

Other food intolerances, too, can aggravate this depressive state. It is always recommended that you  have all possible causes investigated by a medical professional!

A deep depressive state should always be looked into by a doctor!

How do I get rid of the depression?

If the depression is only down to fructose malabsorption, then it will disappear completely if the patient sticks to an appropriate low-sugar and low-fructose diet, avoiding fructose. This will reinstate the tryptophan balance and thus the serotonin levels will return to where they should be!

Sources include:
Ledochowski M, Widner B, Bair H, Probst T, Fuchs D.; Fructose- and sorbitol-reduced diet improves mood and gastrointestinal disturbances in fructose malabsorbers.; Scand J Gastroenterol. 2000 Oct;35(10):1048-52.

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The food intolerance network is a charity that provides worldwide information about lactose intolerance, fructose malabsorption, histamine intolerance, FODMAP-diet and much more. Usage of this website is free of charge. We are funded by the "Society for Public Health" and advertisements that have no influence on the editorial content of our website. Please read our terms of use before you use our services.

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The information provided on the Food Intolerance Network website is no substitute for a visit to a registered dietician, nutritionist or a doctor. The information that you will find here may not be used as a substitute for professional advice and treatment by a medical professional or approved and registered dieticians. The content of the Food Intolerance Network website may not be used as a basis or means for any form of self-diagnosis.

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