Dietary Fructose Intolerance
Department of Food and Nutrition Services,
University of Iowa Hospitals
Peer Review Status: Internally Peer Reviewed
Creation Date: May 2004
Last Revision Date: May 2004
What are the symptoms of DFI?
How is DFI diagnosed?
DFI is diagnosed with hydrogen breath tests. Those include:
- Glucose Breath
Test to rule out bacterial overgrowth.
- Lactose Breath Test to test for intolerance
to milk and milk products.
- Fructose Breath Test to determine intolerance to
- Sucrose Breath Test if indicated from physical and oral history.
- 3C stable
Radioisotope; Breath tests for children and pregnant women.
results of the tests interpreted?
- 10 20 H2, ppm (depending on facility) above
baseline indicates a positive
How does someone prepare for the tests?
Preparation is vital to the success of the tests. Indiscretions can result
in either a false positive or false negative test.
- Do not smoke or perform physical
exercise two hours before testing to
- Rinse mouth with antibacterial mouthwash before testing
to prevent premature hydrogen or carbon dioxide production.
- Eat/drink only
the following foods 24 hours before testing:
- White bread
(limit to 6)
- White potato
- White rice
- Chicken breast
- Turkey breast
What causes DFI?
As yet there are only theories. Some of those are:
- Abnormalities in GLUTE5,
a fructose transporter
- Celiac Disease (transitional)
- Chemotherapy (transitional)
- Familial predisposition
- Injury to the intestinal lining
- Overuse of High Fructose Corn Syrup (HFCS)
- Motility problems
- Rapid gastric emptying of liquids
- Rapid intestinal transit
What is the treatment for DFI?
There currently is no specific enzyme developed to break down fructose.
Until an enzyme is developed the only treatment is to follow the
diet and include dextrose (a simple sugar) with your food.