What is Fructose intolerance?
Fructose intolerance results from the inability to digest fructose, a sugar molecule found naturally in honey, agave nectar, certain fruits and vegetables, and that is also added to foods in the form of pure fructose, crystalline fructose or high fructose corn syrup.
Our small intestines are lined with specific receptors whose job it is to attach to fructose and bring it into the bloodstream from the intestine. Some people express more of these receptors in their guts than other people, which means some people can absorb larger quantities of fructose than others. When a person consumes more fructose from food or drink than they have the capacity to absorb into the body, the unabsorbed fructose passes into the colon, where intestinal bacteria digest it, producing gas, bloating and discomfort.
Fructose intolerance is fairly common, and it may account for chronic digestive symptoms that have been incorrectly attributed to other conditions, such as irritable bowel syndrome (IBS). The inability to digest fructose properly usually results from genetics.
How do we diagnose fructose intolerance?
Often, it is our dietitians who will suggest that you be tested for fructose intolerance based on a detailed food and symptom history. To confirm the diagnosis, we can do a breath test in the office that proves the disorder. During this non-invasive test, we ask you to consume a solution containing fructose, and then measure indirectly the ability of your body to absorb fructose by assessing the chemistry of the air you exhale during the next 180 minutes.
How do we manage fructose intolerance?
There is no way to increase your body’s absorptive capacity for fructose. If you have received a fructose intolerance diagnosis, you will likely be treated through some combination of supplemental enzyme use and diet change. An over-the-counter enzyme supplement is available and may help you comfortably tolerate fructose-containing foods when dosed properly before a meal. Knowing which foods and drinks contain fructose—especially in concentrated amounts—is also part of a symptom management strategy, as some people choose to (or find they need to) avoid these foods altogether.
Our expert GI dietitians will help you understand what foods contain fructose, how to read food labels on a low fructose diet, which sweeteners are likely to be safe and well tolerated, and how to navigate eating when you are not able to use your enzyme supplement.
If you have fructose intolerance, consuming fructose will be uncomfortable but it is not dangerous – it does not cause long-term damage to the intestine.