Exploring the Symptoms, Diagnosis, Testing, Causes and Treatment of Fructose Intolerance
What is DFI?
Dietary Fructose Intolerance (DFI)
DFI is the inability to absorb fructose efficiently. Fructose is broken down by bacteria into short chain fatty acids, carbon dioxide and hydrogen. Fructose is associated with low plasma folic acid concentrations, low serum tryptophan and zinc, moderately elevated serum amylase and lipase concentrations, elevated plasma and liver triglyceride, hepatic lipogenesis, fatty acid oxidation, mental depression, and lower Vitamin C, Vitamin E and glutathione activities.
Hereditary Fructose Intolerance (HFI) should not be confused with Dietary Fructose Intolerance. HFI is a deficiency of a hepatic enzyme (fructose-1,6 diphosphatase) causing acute inhibition of hepatic glucose output when fructose is ingested. HFI leads to hypoglycemia, acidosis, accumulation of gluconeogenic precursors, and, if untreated, can lead to an enlarged liver and mental retardation.
What are the symptoms of DFI?
- Abdominal pain
- Weight loss
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 fructose.
- Sucrose Breath Test if indicated from physical and oral history.
- 3C stable Radioisotope; Breath tests for children and pregnant women.
How are results of the tests interpreted?
10 – 20 H2, ppm (depending on facility) above baseline indicates a positive result.
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 avoid hyperventilation.
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)
What causes DFI?
As yet there are only theories. Some of those are:
Abnormalities in GLUTE5, a fructose transporter
Celiac Disease (transitional)
Injury to the intestinal lining
Overuse of High Fructose Corn Syrup (HFCS)
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.
Source: University of Iowa