Dietary Fructose and Gastrointestinal Symptoms: A Review

Abstract

It has been proposed that fructose may cause or aggravate symptoms in patients with functional gastrointestinal disorders. Fructose is commonly used to sweeten processed foods, and the prevalence of incomplete fructose absorption (25 g, 10%) in healthy subjects is as high as 50%. The only controlled study that has been performed did not demonstrate a higher prevalence of fructose-induced gastrointestinal symptoms or incomplete fructose absorption in patients with functional gastrointestinal disorders. The amount and concentration of fructose used to evaluate absorption by breath testing has varied among studies. Moreover, dietary sources of fructose usually contain glucose, which increases fructose absorption in healthy subjects. Thus, breath testing with fructose alone may not reflect fructose ingestion under normal circumstances. Given these limitations, we suggest that a practical, empirical approach to testing in patients with suspected incomplete fructose absorption is to restrict fructose ingestion. Additional controlled studies are needed to clarify the relation between incomplete fructose absorption and symptoms, assess the effects of co-ingestion of other sugars on fructose absorption, and evaluate the effects of eliminating sugars from the diet on gastrointestinal symptoms.

Prevalence of Fructose Malabsorption in Patients With Irritable Bowel Syndrome After Excluding Small Intestinal Bacterial Overgrowth

“…5 Glucose increases intestinal fructose absorption through passive diffusion as well as the solvent dragging effect. 6,7 However, because fructose is a monosaccharide, excessive dietary intake can easily exceed the absorptive capacity of the small bowel, leading to incomplete absorption of fructose and, finally, causing fructose malabsorption (FM). 1 The unabsorbed fructose may play a role in osmotic load and is therefore rapidly propelled into the colon, where its contact with anaerobic microbiomes causes fermentation and the production of gaseous feeling, abdominal bloating, and even diarrhea.…”

Síndrome do ceco móvel e as doenças gastrintestinais funcionais

“…Assim, baseados no empirismo, podemos escolher um ou mais remédios para diarréia, um ou mais remédios para a constipação, um ou mais remédios para a dor abdominal, além dos ansiolíticos, dos antidepressivos, dos procinéticos, dos probióticos, dos antibióticos e das alterações dietéticas, quando acréscimos ou restrições nem sempre são bem sucedidos. [21][22][23][24][25] Tanto é que os estudos e os tratamentos de caráter alternativos, tais como a psicoterapia convencional, psicoterapia cognitivo-comportamental, hipnoterapia, acupuntura, entre outras, encontram apoio nesse campo [26][27][28][29] , mas não trazem soluções.…”

Fructose‐induced symptoms beyond malabsorption in FGID

“…1,20 There are also issues in the heterogeneity of methodologies used (e.g. ingested dose and concentration of fructose used), and gastrointestinal symptoms have poor correlation with breath hydrogen levels 21 and can appear independent of carbohydrate malabsorption.…”

“…18 Intestinal fructose absorption is facilitated by co-ingestion with glucose due to the solvent drag and passive diffusion by the GLUT2 mechanism. 1,8 Increasing GLUT5 expression by the presence of luminal fructose or sucrose, co-ingestion of amino acids, or altering the insertion of GLUT2 into the apical membrane, such as in the case of diabetes, can also increase fructose uptake. 19 Sorbitol ingestion impedes fructose absorption.…”

“…1 The underlying mechanism of fructose absorption is thought to be due to an individual's transporter function capability capacity, dictated by expression of the respective transporters. In this issue, a study by Wilder-Smith et al 2 provides insight into the mechanism of fructose malabsorption and for the first time assesses whether a direct correlation exists between the expression of the main intestinal fructose transporter proteins and patients with FGID.…”