Fructose intolerance, also known as hereditary fructose intolerance (HFI), is a rare genetic disorder that affects the body's ability to metabolize fructose. It is caused by a deficiency of the enzyme aldolase B, which is responsible for breaking down fructose in the liver. When fructose is not properly metabolized, it can lead to a range of symptoms including abdominal pain, bloating, diarrhea, and vomiting.
Diagnosing fructose intolerance can be challenging as its symptoms can be similar to other gastrointestinal disorders. However, there are several methods that healthcare professionals use to determine if someone has fructose intolerance:
1. Medical History: The first step in diagnosing fructose intolerance is taking a detailed medical history. The healthcare provider will ask about the patient's symptoms, their frequency and duration, as well as any family history of fructose intolerance or other related conditions.
2. Physical Examination: A physical examination may be conducted to assess the patient's overall health and look for any signs of fructose intolerance, such as abdominal tenderness or distension.
3. Elimination Diet: An elimination diet is often used to identify food intolerances, including fructose intolerance. This involves removing all sources of fructose from the diet for a period of time, typically 2-4 weeks, and then gradually reintroducing fructose-containing foods while monitoring symptoms. If symptoms reappear after reintroducing fructose, it may indicate fructose intolerance.
4. Hydrogen Breath Test: This non-invasive test measures the amount of hydrogen in the breath after consuming a fructose solution. In individuals with fructose intolerance, undigested fructose in the intestine is fermented by bacteria, leading to the production of hydrogen gas. Elevated levels of hydrogen in the breath can indicate fructose malabsorption.
5. Genetic Testing: Genetic testing can confirm a diagnosis of hereditary fructose intolerance. It involves analyzing a blood sample to identify mutations in the aldolase B gene, which is responsible for the enzyme deficiency.
6. Liver Biopsy: In some cases, a liver biopsy may be performed to assess the activity of the aldolase B enzyme. This involves taking a small sample of liver tissue for analysis under a microscope.
It is important to consult with a healthcare professional for an accurate diagnosis of fructose intolerance. They will consider the patient's medical history, symptoms, and the results of diagnostic tests to make an informed diagnosis. Once diagnosed, individuals with fructose intolerance can manage their condition by following a fructose-restricted diet and avoiding foods high in fructose.