Is there a link between celiac disease and fructose intolerance/fructose malabsorption?
There are two types of fructose intolerance. The hereditary fructose intolerance, an inherited disturbance of the fructose metabolism, is a rare enzyme defect which concerns the breakdown of fructose in the liver. It is caused by the absence of the enzyme Aldolase B. The consequences are light to strong hypoglycaemia (low blood sugar). The intestinal fructose intolerance, normally called fructose malabsorption, is much more frequent. About 30-40% of the population is affected. The cause of fructose malabsorption is a defect of the transport protein GLUT-5, which normally transports the fructose through the mucous membrane of the small intestine. With a fructose malabsorption this does not happen and the fructose reaches the large intestine where it causes symptoms such as flatulence, stomach ache and diarrhoea. The therapy for a fructose malabsorption is a fructose low diet, whereby the individual tolerance level of fructose greatly varies. In addition artificial sugars such as Sorbitol, Mannitol and Xylitol must be avoided as they furthermore inhibit fructose absorption. According to studies food containing proportionally more glucose than fructose is generally better tolerated. Lists containing permitted food items exist. With coeliac disease, through the damaging of the mucosa of the small intestine, a temporary fructose intolerance can develop. This generally disappears once the mucosa has regenerated itself through a gluten-free diet.