What is fructose malabsorption?

Fructose malabsorption VS. Fructose Intolerance

Fructose intolerance and fructose malabsorption are often used interchangeably, but they’re not the same thing. Fructose malabsorption is a digestive issue where the gut struggles to absorb fructose properly. Hereditary fructose intolerance (HFI) is different and more serious. It’s a genetic disorder in which the body lacks the enzyme aldolase B, needed to break down fructose. HFI is sometimes mistakenly called an “allergy,” but it’s actually a metabolic disorder, not an allergic reaction. Symptoms can include severe abdominal pain, vomiting, and low blood sugar (hypoglycemia) (3).

What is fructose malabsorption?

Fructose malabsorption (sometimes referred to as sugar malabsorption) is a condition where the body struggles to absorb fructose effectively in the small intestine. Fructose, a natural sugar found in fruits, vegetables, and many processed foods, is usually absorbed with the help of a specific transport protein called GLUT-5. In individuals with fructose malabsorption, this process is impaired, causing fructose to remain in the digestive tract where it ferments, leading to discomfort and symptoms. Understanding fructose malabsorption symptoms, causes, and treatments is key to managing this condition (2).

Want help to reduce associated symptoms? Fructase contains Xylose Isomerase and helps with the digestion of Fructose.*

What are common symptoms?

Fructose malabsorption symptoms often manifest as digestive issues due to the fermentation of unabsorbed fructose in the colon. These symptoms can include:

• Abdominal pain and bloating
• Diarrhea or constipation
• Flatulence
• Intestinal cramps

Additionally, fructose intolerance (malabsorption) can contribute to non-digestive symptoms like fatigue, irritability, and even low mood. This connection arises because excess fructose can interfere with serotonin production by binding to tryptophan, a precursor to serotonin.

What are the causes?

Fructose malabsorption is primarily caused by a deficiency or dysfunction of GLUT-5 transport proteins. Without adequate functioning of these proteins, fructose absorption in the small intestine is hindered. While some people are born with this sensitivity, others may develop it due to gastrointestinal disorders such as irritable bowel syndrome (IBS) or after certain infections that damage the intestinal lining. Dietary habits rich in free fructose, commonly found in processed foods sweetened with high-fructose corn syrup, can also exacerbate symptoms (2).

How do i manage fructose malabsorption in my diet?

A carefully planned fructose malabsorption diet is one of the most effective ways to manage symptoms. Here are practical dietary strategies:

1. Limit high-fructose foods: Foods such as apples, pears, honey, and high-fructose corn syrup should be avoided or limited.
2. Focus on balanced ratios: When consuming fructose-containing foods, pair them with equal or higher amounts of glucose. Glucose assists in fructose absorption via the GLUT-2 protein, reducing the likelihood of free fructose reaching the large intestine.
3. Consult the low FODMAP diet: This dietary approach, which limits fermentable sugars, can be beneficial for identifying and managing trigger foods. Apps like Monash University’s Low FODMAP app provide a convenient reference.

For those unsure about dietary adjustments, consulting a dietitian can provide tailored guidance for a fructose-restricted or fructose-free diet.

What are supplements for fructose intolerance / malabsorption?

Enzymatic supplements play a valuable role in managing fructose malabsorption. Fructose malabsorption supplements containing xylose isomerase can help reduce symptoms by converting fructose into glucose, which is more readily absorbed by the intestine.* (1,2). These supplements are particularly useful when consuming meals that contain unavoidable fructose. Always consult a healthcare professional before starting any fructose malabsorption supplement to ensure it aligns with your individual needs.

Fructose malabsorption and fructans
Sensitivity to fructans, chains of fructose molecules, often accompanies fructose malabsorption. Fructans are found in foods like onions, garlic, and wheat. During digestion, these fructans release fructose, which can worsen symptoms in susceptible individuals. Avoiding fructan-rich foods may further help in reducing symptoms.

Long-term management and treatment options
While there is no cure for the condition, long-term management involves a combination of dietary adjustments, supplements, and ongoing symptom monitoring. A fructose malabsorption treatment plan should include:

• Regular tracking of food intake and symptoms to identify and avoid triggers.
• Gradual reintroduction of suspect foods under professional supervision to determine tolerance levels.
• Addressing underlying conditions like IBS to reduce overall gastrointestinal sensitivity.

What foods should i watch out for?

Fructose is present in many natural and processed foods. Common sources include:

• Fruits: Apples, pears, watermelon, and mangoes
• Sweeteners: Honey, high-fructose corn syrup, and agave syrup
• Vegetables: Asparagus, artichokes, and sugar snaps
• Beverages: Soft drinks, fruit juices, and sweetened teas

Reading food labels carefully is crucial, as fructose can appear under various names, including fructose syrup or crystalline fructose.

Professional Guidance:

You can read more about the topic in our knowledge bank or you can contact one of our dieticians for personalized advice. If you’re facing symptoms and don’t know where they come from, you can take the intolerance test for more information:

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.