The following article is sourced from Wikipedia. As this is an open source on-line information source it is contributed to by many people and continually evolves. While its reliability is not guaranteed, the snippets of information included below provide a relatively detailed snapshot of this issue and its connection with coeliacs. That is many of the foods that coeliacs should not eat are the same for people with fructose issues.
Fructose malabsorption or Dietary Fructose Intolerance is a digestive disorder of the small intestine in which the fructose carrier in enterocytes is deficient. As a result of this problem, the concentration of fructose in the entire intestine is increased. Fructose malabsorption is found in approximately 30-40% of the population of Central Europe, with about half of the affected individuals exhibiting symptoms.
Medical tests are similar as in lactose intolerance, requiring a hydrogen breath test for a clinical diagnosis. When breath test can not be done from some reason, reducing substances in the stool, and subsequently fructose in the stool can be checked.
It can be associated with reduced plasma tryptophan and clinical depression.Diagnosis Medical tests are similar as in lactose intolerance, requiring a hydrogen breath test for a clinical diagnosis. When breath test can not be done from some reason, reducing substances in the stool, and subsequently fructose in the stool can be checked.
It can be associated with reduced plasma tryptophan and clinical depression.
Fructose Malabsorption is not to be confused with Hereditary Fructose Intolerance (HFI), a condition in which the liver enzymes that break up fructose are deficient. In patients with fructose malabsorption, the small intestine fails to absorb fructose properly. In the large intestine the unabsorbed fructose osmotically reduces the absorption of water and is metabolized by normal colonic bacteria to short chain fatty acids and the gases hydrogen, carbon dioxide and methane. The abnormal increase in hydrogen is detected with the hydrogen breath test.
The physiological consequences of fructose malabsorption include increasing osmotic load, providing substrate for rapid bacterial fermentation, changing gastrointestinal motility, promoting mucosal biofilm and altering the profile of bacteria. These effects are additive with other short-chain poorly absorbed carbohydrates such as sorbitol. The clinical significance of these events depends upon the response of the bowel to such changes; they have a higher chance of inducing symptoms in patients with functional gut disorders than asymptomatic subjects. Some effects of fructose malabsorption are decreased tryptophan, folic acid and zinc in the blood. Restricting dietary intake of free fructose and/or fructans may have durable symptomatic benefits in a high proportion of patients with functional gut disorders, but high quality evidence is lacking.
There is no known cure, but an appropriate diet will help. However, 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. However, depending upon the sufferer's sensitivity to fructose, small amounts of problem foods could be eaten (especially when they are not the main ingredient of a meal).
Foods with a high glucose content actually help sufferers absorb fructose.
This condition is common in patients with symptoms of Irritable Bowel Syndrome and most patients with fructose malabsorption fit the profile of those with Irritable Bowel Syndrome. A small proportion of patients with both fructose malabsorption and lactose intolerance also suffer from celiac disease.
Typical symptoms of fructose malabsorption include:
Bloating (because of fermentation in the small and large intestine) Diarrhea and / or constipation Flatulence 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 Fatigue Depression as a result of absorption disorders in the small and large intestines, other substances such as amino acids are not absorbed. Because of missing substances (among others tryptophan), hormones and neurotransmitters cannot be synthesized.
Foods of concern / Foods with high fructose content
According to the USDA database, foods with more fructose than glucose include:
- Fruit juice - e.g. Apples,Pears
- High fructosecorn syrup
There is a lot of misinformation and misconception about fruit sugar content. A common belief is that fruits contain mainly, or only, fructose sugar. The USDA food database reveals that many common fruits contain nearly equal amounts of the fructose and glucose. There is a tendency within plants to keep these sugars 50/50. The only aberrantly high fructose fruits are apple and pear, which have twice as much fructose as glucose. Fructose levels in grapes varies with ripeness and variety, with unripe grapes containing more glucose.
Foods with high fructan content
Chains of fructose molecules, known as fructans occur naturally in many foods. The following foods have a high fructan content:
Artichokes, Asparagus, Leeks, Onions (including spring onion), Wheat (including most beers), breads, cakes, biscuits, breakfast cereals, pies, pastas, pizzas, and some noodles.
The role that fructans play in fructose malabsorption is still under investigation. However, it is recommended that fructan intake for fructose malabsorber should be kept to less than 0.5 grams/serving and supplements with inulin and fructooligosaccharide (FOS), fructans, intake should be avoided.
Other problem foods
In addition, the following foods can cause symptoms of fructose malabsorption:
Sodas and other beverages containing high fructose corn syrup, 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.
Unfavorable foods (i.e. more fructose than glucose)
Fruit - Apple, pear, guava, honeydew melon, nashi fruit, pawpaw/papaya, quince, star fruit, watermelon Dried fruit - Apple, apricot, currant, date, fig, pear, prune, raisin, sultana Fruit juices Fruit pastes - chutney, relish, plum sauce, sweet & sour sauce, BBQ sauce. Coconut Dried fruit bars Honey Fortified wines High Fructose Corn Syrup - Many processed products contain this Corn syrup solids Fruit juice concentrates.
For a controversial view of how fructose malabsorption might be acquired, see: