Frequently Asked Questions About Fructose Malabsorption

When having fructose malabsorption, which was formerly named dietary fructose intolerance (DFI) your body can’t absorb fructose very well along its small intestine. Remaining fructose that reaches the colon gets fermented by bacteria and causes bloating, cramps, pain, and diarrhea.

In contrast, hereditary fructose intolerance (HFI) is a genetic disorder where the liver is not able to help breaking down the fructose, which can lead to severe toxic symptoms, such as tremors, vomiting, and disorientation, after fructose ingestion.

Having fructose malabsorption means getting symptoms like bloating, cramps, stomach ache, and diarrhea after almost any meals, when not knowing which foods are safe. Brain fog and sudden mood swings can also happen. Symptoms occur typically after eating sweet food, fruits, food with lots of spices, onions or garlic. Read more about common symptoms and why even depression can be a consequence of fructose malabsorption on my Fructose Malabsorption Facts page.

Fructose malabsorption can develop due to a bad diet, such as eating too much fructose-rich foods, environmental pollution, chronic stress, inflammation, an imbalance of bacteria in your gut, or preexisting gut issues.

If you are suffering from bloating, cramps, or diarrhea after consuming foods with fructose this may be a sign of fructose malabsorption. But symptoms can vary from person to person as well as the tolerable amount of fructose. So, you can’t know for certain that you have it until you have made a professional hydrogen breath test. First, you will have to consume a certain amount of fructose. Then breaths samples are taken during the next three hours. If the amount of hydrogen rises above a certain treshhold it indicates that your body has problems in absorbing fructose properly.

Symptoms of fructose malabsorption are typically bloating, cramps, stomach ache, and diarrhea. As a consequence of diarrhea and the fact that less fructose gets absorbed and that fructose malabsorption affects the joy of eating, weight loss is more likely a consequence of fructose malabsorption than weight gain.

Dealing with fructose malabsorption requires knowledge of the foods to avoid, following a strict diet and keeping a food diary to find your own thresholds and foods that are still tolerable. You can also add the enzyme xylose isomerase to fructose-rich food for balancing out fructose and glucose or consume glucose simultaneously with fructose, as it acts as piggyback transporter.

Unfortunately, there is no simple cure to fructose malabsorption. But a proper diet and the supplementation of the enzyme xylose isomerase can help to improve the symptoms significantly. Some people also reported that they could restore normal gut function after months or sometimes years of following a strict diet. This website will show you how to manage fructose malabsorption successfully and avoid common mistakes.

Fructose can be broken down by the enzyme xylose isomerase, which is not made by the human body but can be bought as a supplement to avoid symptoms of fructose malabsorption when eating food with excess fructose. 

This enzyme leads to a balance between glucose and fructose, as it converts excess fructose into glucose and vice versa. As glucose acts as a piggyback transport for fructose a balanced ratio leads to improved symptoms. Read more about xylose isomerase, how it works, and where to get it on my Fructose Malabsorption Medication page.

Fructans and fructose are both FODMAPs, but they are quite different. Fructans are polysaccharides consisting of several short chains of the monosaccharide fructose. They are called fructooligosaccharides when they consist of 2-9 fructose units, and inulins when having more than 10 units. Foods that have high amounts of fructans are onions, garlic, and artichokes.

Our body doesn’t have enzymes for breaking down fructans. This means, that fructans get fermented in the large intestine even in healthy individuals, which results in variable amounts of gas. For those with fructose malabsorption fructans can worsen symptoms drastically and should be strictly avoided.