If you tend to experience tummy troubles after you eat fruits and sweets, you might have difficulty digesting fructose. Fruits, honey and some types of syrup, including the much-maligned high-fructose corn syrup, contain this type of sugar. Anything that has regular table sugar in it has some fructose as well, since it is made up of a combo of fructose and glucose.
Intolerance versus Malabsorption
If you suffer from fructose intolerance, you don't have the enzyme necessary for breaking down fructose. This causes your blood sugar levels to be too low and uric acid to build up in your blood, potentially leading to kidney and liver damage. Some people suffer from a less serious condition called fructose malabsorption, in which consuming fructose leads to unpleasant abdominal symptoms but doesn't cause organ damage.
Fructose malabsorption symptoms include diarrhea, bloating, gas and stomach pain. While these symptoms are uncomfortable, they usually aren't very serious. Symptoms of fructose intolerance can be more serious, including jaundice, or yellow skin, irritability, problems eating foods containing sucrose or fructose, excessive sleepiness, convulsions and vomiting. Fructose intolerance can also cause you to have an enlarged spleen and liver.
A number of tests can help diagnose fructose intolerance. Blood tests will show high levels of uric acid and low blood sugar. Sometimes a DNA test is performed, since this is a hereditary condition that runs in families. A urine test can also help with the diagnosis, and enzyme studies can show whether or not you can produce the necessary enzyme, called aldolase B.
The sooner fructose intolerance is diagnosed, the more likely you can avoid organ damage. Treatment for this condition includes avoiding all foods that contain fructose, sucrose and sorbitol. All foods containing powdered sugar, honey, high-fructose corn syrup and table sugar should be avoided, as well as fruit juice, sodas, sports drinks and other sweetened beverages. If you have high levels of uric acid in your blood, you may need to take medications to lower these so you don't get gout, a type of arthritis.
Based in Massachusetts, Jessica Bruso has been writing since 2008. She holds a master of science degree in food policy and applied nutrition and a bachelor of arts degree in international relations, both from Tufts University.