Are you often bloated, gassy, or uncomfortable after eating fruit or sweets? You might be dealing with fructose intolerance — a condition where your body has difficulty absorbing fructose, a natural sugar found in fruits, honey, and many processed foods. Understanding what fructose intolerance is, its symptoms, and which foods to avoid can help you feel better and improve your digestion.
What is fructose?
Fructose is a type of simple sugar naturally found in fruits, honey, and certain vegetables. It is also part of table sugar (sucrose), which combines fructose and glucose. Many packaged foods and drinks contain added fructose or high-fructose corn syrup, making it easy to consume more than the body can handle.
Some vegetables and processed foods also contain fructans (chains of fructose) or sorbitol, a sugar alcohol often used as a sweetener. Both of these can worsen symptoms in people sensitive to fructose and are typically limited in a low-fructose diet plan.
Difference between intolerance and malabsorption
Before learning how to manage fructose intolerance, it’s important to understand that intolerance and malabsorption are not exactly the same thing. Both affect how your body handles fructose, but the underlying causes differ.
When you eat foods containing fructose, this natural sugar is absorbed in the small intestine through a specific transporter called GLUT 5. This transporter moves fructose into the bloodstream, where it’s later processed by the liver. Another transporter, known as GLUT 2, helps absorb other sugars such as glucose and galactose.
In some people, fructose malabsorption occurs because the body produces too little of the GLUT 5 transporter or it doesn’t work properly. As a result, unabsorbed fructose moves into the large intestine, where it ferments and produces gas — leading to bloating, cramps, and diarrhea.
The presence of another sugar alcohol, sorbitol (often used in sugar-free candies and diet products), can make things worse. Sorbitol competes with fructose for absorption because both use the same GLUT 5 transporter. This is why low-fructose diets also limit sorbitol intake.
In summary: Malabsorption refers to the difficulty in absorbing fructose, while intolerance describes the symptoms that appear as a result — like bloating, gas, or pain. Understanding this distinction helps create a more effective fructose intolerance diet plan tailored to each person’s needs.
Types of fructose intolerance
There are two types of fructose intolerance:
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Primary or hereditary fructose intolerance: There is a deficiency or absence of the aldolase B enzyme, genetically mediated, so it is hereditary. It is less common. Fructose consumption is limited for life; it is evaluated with a genetic study.
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Secondary fructose intolerance or malabsorption: This is more frequent and evaluated with a breath test. As its name indicates, it is secondary to another pathology, usually related to the presence of intestinal diseases such as:
- Inflammatory bowel disease
- Irritable bowel syndrome
- Gastroenteritis
- Celiac disease
- Bacterial overgrowth
If the intestinal disease is cured, the intolerance usually also disappears.
Symptoms of fructose intolerance
If there is fructose intolerance or malabsorption, some of the following symptoms may occur:
- Flatulence and gas
- Abdominal distension
- Diarrhea (explosive)
- Intestinal noises, vomiting, and/or nausea
- Stomach cramps
- Abdominal pain
- Constipation
- Weakness
Long-term fructose intolerance can also cause deficiencies in micronutrients, changes in the gut microbiome, or increased intestinal permeability.
Diet for fructose intolerance
When planning a diet for someone with fructose intolerance, we must keep in mind that both the degree of malabsorption and the degree of intolerance are not the same for all patients; it will vary depending on the patient's transporter deficit and intestinal sensitivity. So it is very important to individualize and customize the dietary guidelines.
Some people with limited fructose absorption capacity may have intolerance symptoms produced by unabsorbed fructose that reaches the colon. In this case, the objective is to limit the intake of foods rich in fructose to a level that does not cause symptoms, according to individual tolerance. Partial restriction is sufficient, maintaining these foods in the diet in tolerable quantities to avoid the risk of nutritional deficiencies.
The capacity to absorb fructose improves with the simultaneous intake of glucose, which generally means good tolerance to sucrose or common sugar. On the other hand, sorbitol present in some foods naturally or as an additive (E-420) increases the risk of symptoms.
Recommendations for improving fructose intolerance
Recommendations to Improve Fructose and Sorbitol Tolerance:
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The best-tolerated fruits:
- Oranges, tangerines, bananas, lemons, avocados, kiwis, blackberries, strawberries, blueberries, raspberries, grapefruit, grapes, and melons.
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Eat small portions and space fruit servings:
- Limit yourself to one fruit serving or equivalent at a time, with a maximum of 2–3 servings per day.
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Best-tolerated vegetables:
- Broccoli, chard, spinach, celery, artichokes, watercress, tapioca, mushrooms, lettuce, endive, and chicory. Older potatoes contain lower fructose levels than new potatoes.
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Cook vegetables: Cooking reduces fructose (it is lost in the cooking liquid, which should be discarded), making them easier to tolerate.
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Limit high-fructose and mixed-fructose/sorbitol foods: These include apples, pears, plums, cherries, peaches, apricots, commercial fruit juices, and sweets (chewing gum, candies, etc.).
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Choose unprocessed animal proteins: Foods of animal origin (meat, fish, eggs, etc.) can be safely consumed if they are not processed. Fructose and sorbitol may be added during processing.
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Avoid sweetened drinks and check medications: In general, it is best to avoid commercial fruit drinks (juices and soda) and all products sweetened with fructose and sorbitol. Many medications in syrup form contain glucose or sorbitol — consult your doctor for alternatives when necessary.
Related articles:
- The 10 Foods That Lower Blood Sugar Level
- Low-Fructose Diet for Hormonal Balance in Women Over 40
- Low-Fructose Meal Plan for Bloating-Free Energy
2025 Update: Latest Research on Fructose Intolerance
Recent studies suggest that maintaining gut health through probiotics may improve fructose absorption. Dietitians now recommend introducing low-fructose foods gradually rather than strict elimination to preserve microbiome balance.
FAQs About Fructose Intolerance
Can fructose intolerance be cured?
Primary (hereditary) fructose intolerance cannot be cured, but secondary intolerance often improves when the underlying gut issue is treated.
What foods are safe if I have fructose intolerance?
Low-fructose fruits like oranges, bananas, and berries are usually well tolerated, along with most meats and cooked vegetables.
How do I know if I have fructose malabsorption?
A hydrogen breath test is the most common diagnostic method for detecting fructose malabsorption.
