Fructose Malabsorption (Intolerance)

Jason A. Ohayon MD FRCP(C) FAAP Consulting Allergy and Clinical Immunology For Adults and Children

1685 Main St. West Suite 201 Hamilton, ON L8S 1G5 905-777-0088, fax 905-777-0018

Fructose Malabsorption (Intolerance) If you have any additional questions about nutrition or healthy eating, call EatRight Ontario toll-free at 1-877-510-5102 Visit the EatRight Ontario website at www.Ontario.ca/EatRight

Symptoms •Bloating (from fermentation in the small and large intestine) •Diarrhea and/or constipation •Flatulence •Stomach pain (as a result of muscle spasms, the intensity of which can vary from mild and chronic to acute but erratic) •Vomiting (if great quantities are consumed) •Early signs of mental depression[8] Diagnosis The diagnostic test, when used, is similar to that used to diagnose lactose intolerance. It is called a hydrogen breath test and is the method currently used for a clinical diagnosis. When a breath test cannot be performed, a stool test may be used.[9] Treatment There is no known cure, but an appropriate diet will help. Diet Foods that should be avoided by people with fructose malabsorption include: •Foods and beverages containing greater than 0.5g fructose in excess of glucose per 100g, greater than 3g fructose in an average serving quantity regardless of glucose intake and greater than 0.2g of fructans per serving.[10] •Fructose consumed in large quantities •Foods with high fructose-to-glucose ratio (NB: Glucose enhances absorption of fructose, so fructose from foods with fructose-to-glucose ratio <1, like bananas, are readily absorbed, while foods with fructose-to-glucose ratio >1, like apples and pears, are often problematic regardless of total amount of fructose in the food[11] •Foods rich in fructans and other Fermentable Oligo-, Di- and Mono-saccharides and Polyols (FODMAPs) •Foods rich in sorbitol •Foods such as high fructose corn syrup (HFCS) or honey Foods with a high glucose content ingested with foods containing excess fructose may help sufferers absorb the excess fructose.[12] The USDA food database reveals that many common fruits contain nearly equal amounts of the fructose and glucose, and they do not present problems for those individuals with fructose malabsorption.[14] Some fruits with a greater ratio of fructose than glucose are apples, pears and watermelon, which contain more than twice as much fructose as glucose. Fructose levels in grapes varies depending on ripeness and variety, where unripe grapes contain 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 malabsorbers should be kept to less than 0.5 grams/serving[15], and supplements with inulin and fructooligosaccharide (FOS), both fructans, should be avoided.[15] Other problem foods In addition, the following foods should also be avoided: •Sorbitol (present in some diet drinks and foods, and occurring naturally in some stone fruits) •Xylitol present in some berries, and other polyols (sugar alcohols), such as erythritol, mannitol, and other ingredients that end with -tol, commonly added as artificial sweeteners in commercial foods. •Any processed foods or foods prepared by others containing the foods listed above ◦For example: ■Sodas and other beverages containing high fructose corn syrup (HFCS) ■Dried fruit (including "health" bars containing dried fruit) ■Tinned fruit in "natural" juice (often, this is pear juice) ■Sweet wines Dietary guidelines for the management of fructose malabsorption Dietary guidelines[15] have been developed for managing fructose malabsorption particularly for individuals with IBS. 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, currant, date, fig, pear, raisin, sultana •Honey •Fortified wines •High Fructose Corn Syrup - many processed products contain this •Corn syrup solids •Fruit juice concentrates •Agave nectar •Red Ripe Tomato Favorable foods (i.e. fructose equal to or less than glucose) •Stone fruit: apricot, nectarine, peach, plum (caution - these fruits contain sorbitol) •Berry fruit: blueberry, blackberry, boysenberry, cranberry, raspberry, strawberry, loganberry •Citrus fruit: kumquat, grapefruit, lemon, lime, mandarin, orange, tangelo •Other fruits: ripe banana, jackfruit, kiwi fruit, passion fruit, pineapple, rhubarb, tamarillo http://en.wikipedia.org/wiki/Fructose_malabsorption