Letzte Aktualisierung am 9. September 2024 von Dr. Michael Zechmann-Khreis
There are several diseases that are associated with fructose intolerance . This is not always scientifically substantiated. In this article, we want to get to the bottom of two of these secondary diseases and their connection with fructose intolerance.
Fatty liver due to fructose intolerance
Whether fructose intolerance is associated with what used to be called non-alcoholic fatty liver disease (NAFLD) or its inflammatory form, NASH syndrome (non-alcoholic steatohepatitis), is still the subject of heated debate. It is repeatedly reported in Internet forums that many people with fructose intolerance suffer from a fatty liver. There could be many reasons for this. For example, that increased glucose consumption is crucial for people with fructose intolerance. Whether there is a direct connection will certainly be investigated in the coming years. A connection cannot therefore be clearly confirmed at present.
Today, this symptom pattern is called “metabolic dysfunction-associated fatty liver disease” (MAFLD) 5-6
Symptoms of fatty liver
Fatty liver usually causes no or only very minor symptoms! Some symptoms that occur repeatedly and have been described by some patients are
- Feeling of fullness
- Lack of drive / cf. depression with fructose malabsorption
- Feeling of pressure in the right abdomen
- Discomfort when lying on the right side (nausea, pain)
- General physical and mental reduction in performance and lack of drive
What to do about fatty liver?
This question cannot be fully answered here, as the cause of the fatty liver must be determined! Only your doctor can do this!
In our western world, the phenomenon of an “affluent liver” is becoming increasingly common. It is quite normal for the liver to store fat droplets. If you eat too much and consume too many calories, the amount of fat in the liver increases. The liver becomes fatty and turns into a “fatty liver”. This form of fatty liver can disappear again through dietary measures and exercise. The aim is to exercise and minimize calorie intake. Sugars (mono- and disaccharides) are the main contributors here. Therefore, you should not consume more than 25-50 grams of such added sugars (lactose, fructose, sucrose, …) per day. Added means that they do not occur naturally in food. In other words, sugar in fruit is ok, sugar in coffee or sausage is not. Recent studies show that a balanced microbiome (intestinal flora) can contribute to an improvement in fatty liver disease8), although the data situation here is still relatively uncertain and new findings can be expected in the coming years.
General recommendations:
- Abstaining from alcohol
- Low-fat and low-fructose or low-sugar diet (less than 25 added sugars per day)
- Balanced endurance sport, plenty of exercise in the fresh air
- Slow weight normalization
- Intake of certain intestinal bacteria – in consultation with the doctor
- No smoking4)
Depression and fructose intolerance
There can be various reasons for depressive moods due to fructose intolerance.
According to a study7) , fructose malabsorption is associated with reduced absorption of the amino acid tryptophan, i.e. slightly less tryptophan is detectable in the blood of fructose malabsorbers than in the blood of non-intolerant people. Tryptophan is converted into the happiness hormone serotonin in the body. If little tryptophan is available, only little serotonin can be produced. The fatal thing is that the body knows that it needs tryptophan and you are inclined to eat more foods that contain this substance. However, almost all of these foods also contain a lot of fructose. You also often hear that you should eat more fruit, as it is healthy and helps. However, this does not help, but drastically worsens the situation if you have intestinal fructose intolerance. However, this study has never been reproduced or is debatable. This effect has therefore not been proven, but is very often assumed. It is not advisable to take tryptophan without prior blood work.
However, depressive moods (not depression) and fructose intolerance often occur together. There can be various reasons for this. If the intolerance is not treated and the body continues to consume fructose, the symptoms described will occur. In the long term, these symptoms also lead to a deterioration in mental and social health. Other possible causes are the psychological stress to which patients are exposed. The social isolation that patients with undiagnosed fructose intolerance experience should be mentioned here in particular. Due to the diarrhea and constant nausea, patients withdraw more and more from social life, planning their free time more according to available toilets than fun. Other intolerances and their physical consequences can also exacerbate depressive states.
Fructose intolerance can therefore be associated with depressive moods in several ways. Medical clarification of all possibilities is always recommended.
In the case of severe depression, medical clarification is urgently required!
How do I get rid of depression?
If the depressive states are exclusively (!) due to fructose intolerance, they are very likely to disappear if an appropriate low-fructose diet is followed. You can also take tryptophan as a dietary supplement as a precaution. Here it is important to consult the doctor treating you, who must first determine an actual deficiency via the blood. In addition, taking tryptophan is certainly associated with health risks, which is why this substance should never be substituted without medical supervision.
Sources
(1) Lesurtel M., Graf R., Aleil B., et al, Platelet-Derived Serotonin Mediates Liver Regeneration, Science, April 7, 2006
(2) 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.
(3) Stanhope, K.L.; Schwarz, J.M.; Keim, N.L.; et.al; “Consuming fructose-sweetened, not glucose-sweetened, beverages increases visceral adiposity and lipids and decreases insulin sensitivity in overweight/obese humans” in The Journal of Clinical Investigation, doi: 10.1172/JCI37385
(4) Mallat, A.; Lotersztajn “Cigarette smoke exposure: A novel cofactor of NAFLD progression?” in Journal of Hepatology 51 (2009) 430-432, 2009
(5) Roeb, E. et al.
Updated S2k guideline non-alcoholic fatty liver disease of the German Society of Gastroenterology, Digestive and Metabolic Diseases (DGVS) – April 2022 – AWMF register number: 021-025.
Z. For Gastroenterol.
60, 1346-1421 (2022).
(6) Roeb, E. et al.
Amendment “New nomenclature for MASLD (Metabolic Dysfunction Associated Steatotic Liver Disease)” to the S2k guideline “Non-alcoholic fatty liver disease” (v.2.0/April 2022) of the German Society of Gastroenterology, Digestive and Metabolic Diseases (DGVS): March 2024 – AWMF registry number: 021-025.
Z. For Gastroenterol.
62, 1077-1087 (2024).
(7) M. Ledochowski, B. Widner, C. Murr, B. Sperner-Unterweger & D. Fuchs “Fructose Malabsorption is Associated with Decreased Plasma Tryptophan”, Scand J Gastroenterol 2001 (4)
(8) Boursier, J; Maeh Diel, A; “Nonalcoholic Fatty Liver Disease and the Gut Microbiome”, Clin Liver Dis, 2015
(9) Yanai, H., Adachi, H., Hakoshima, M., Iida, S. & Katsuyama, H. Metabolic-Dysfunction-Associated Steatotic Liver Disease-Its Pathophysiology, Association with Atherosclerosis and Cardiovascular Disease, and Treatments. Int.
J. Mol.
Sci. 24, 15473 (2023)
