What is fructose intolerance?

Dr. Jeanne Morrison, PhD
Family Practitioner

Fructose intolerance is an inherited condition. People who have fructose intolerance lack a certain enzyme or chemical that helps process fructose, a certain kind of sugar, found in some foods (usually fruits). Your body needs to use fructose and other sugars to create energy. When your body tries to use the fructose without the enzyme, it produces dangerous byproducts that prevent glycogen from turning to glucose to use as energy. These byproducts can damage your liver and be fatal. Eating a low-fructose diet helps most people control their disease.

Aviva J. Romm, MD
Family Medicine
Fructose intolerance is when you can't properly digest fructose, which can create digestive issues and uncomfortable symptoms. In this video, integrative medicine expert Aviva Romm, MD, explains fructose intolerance, and what you can do to treat it. 
Nancee Jaffe, RD
Nutrition & Dietetics
Fructose intolerance is a condition in which the body doesn't use fructose properly, resulting in gastrointestinal symptoms. Fructose is a type of sugar that looks similar to glucose, but glucose is actually the favorite fuel source of the body. When the body doesn't absorb fructose properly, it travels all the way through the gastrointestinal tract. It carries water with it, and it causes some of those gurgling noises that people have when they're bloated. It can also lead to loose stools. When bacteria in the colon feed on fructose, it causes gas, bloating and pain. A breath test can check for fructose malabsorption.
Patsy Catsos
Nutrition & Dietetics

There are two kinds of fructose intolerance, dietary fructose intolerance and hereditary fructose intolerance (HFI). A person with dietary fructose intolerance gets gastrointestinal symptoms such as bloating, flatulence, diarrhea or abdominal pain from consuming more fructose at one time than he or she can absorb. A fructose-free diet is not required, since most people with dietary fructose intolerance find they can handle small amounts of fructose without becoming symptomatic.

On the other hand, HFI is a rare genetic condition. From birth, a person with HFI can become ill from consuming any amount of fructose no matter how small, so a fructose-free diet is a must.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.