It is a dietary disability of the small intestine caused by a defect in the transport mechanism of the small intestine whereby fructose, the sugar found in fruit cannot be transferred into the blood stream and remains in the gastro intestinal tract causing Carbohydrate Intolerance symptoms.
Fructose Malabsorption is not to be confused with fructose intolerance, a hereditary condition in which the liver enzymes that break fructose up are deficient. In patients with fructose malabsorption, the small intestine fails to absorb fructose properly. This results in excess hydrogen caused by an overgrowth of otherwise normal intestinal bacteria.
This condition is common in patients with symptoms of lactose intolerance and irritable bowel syndrome. A small proportion of patients with both fructose malabsorption and lactose intolerance also suffer from coeliac (celiac) disease. Typical symptoms of fructose malabsorption include:
- diarrhoea and / or constipation
- stomach pain (due to muscle spasms, which can vary from mild and chronic to acute but erratic)
Other possible symptoms of fructose malabsorption include:
- aching eyes
- fuzzy head
Fructose in Foods
Foods with a high fructose content include:
- coconut milk
- fruit juice (especially from from apples and pears)
- high fructose corn syrup (present in some soft drinks, and used to make sushi rice stick together)
Other problem foods
In addition, the following foods can cause symptoms of fructose malabsorption:
- dried fruit (including "health" bars containing dried fruit)
- tinned fruit in "natural" juice (which is often pear juice)
- sorbitol (present in some diet drinks and foods, and occurring naturally in some stone fruits)
- sweet wines
- Too much fruit of any kind in a short timeframe
There is no cure for Fructose malabsorption and it is very difficult for undiagnosed sufferers to see any relationship between the foods they eat and the symptoms they suffer, even if they keep a daily diet diary. This is because most foods contain a mixture of fructose and glucose. Foods with more fructose than glucose are a problem, as are foods with a lot of fructose (regardless of the amount of glucose). The only way of treating it is by limiting the diet to lower levels of fructose. The amounts one can consume asymptomatically varies from one person to another. When this is found out one can stick to that level of fructose in the diet and avoid the symptoms.