Most of the time we eat food, our digestive system quietly does its job of processing the food without us even being aware of it. Sooner or later, though, we’ll eat something that unexpectedly leads to gas, bloating, constipation, diarrhea, or any of a number of other gastrointestinal symptoms. In these times it can take some detective skills to figure out what you ate that caused the problem. Sometimes the effects can be seemingly random or otherwise not from a clear source. In a somewhat narrow segment of the population, though, it might be because of fructose intolerance.
Fructose intolerance, now commonly referred to as fructose malabsorption, is a digestive disorder characterized by the inability to properly absorb fructose. Fructose is a naturally occurring monosaccharide (simple sugar) found in fruits, vegetables, and sweeteners that gets converted by the liver into glucose for energy. A person with fructose malabsorption lacks the necessary enzymes in the small intestine to break down fructose effectively, and this can lead to problems with the gut microbiome that resides in the large intestine.
When undigested fructose does reach the large intestine, the gut bacteria, through the process of fermentation, consume the fructose and break it down into gasses like hydrogen and methane as well as short-chain fatty acids. The abnormal presence of these gasses and acids can then lead to a variety of gastrointestinal symptoms. The severity of the symptoms depend on a person’s individual sensitivity and the amount of fructose consumed. It’s important to note that fructose malabsorption is different from being allergic to fructose, which is instead an immune response to the consumption of fructose.
There are essentially two types of fructose intolerance: dietary fructose intolerance and hereditary fructose intolerance. All humans have a limit on the amount of fructose that can be absorbed by the digestive tract, but people with dietary fructose intolerance are much more sensitive to it on average. Hereditary fructose intolerance (HFI), on the other hand, comes from a genetic error that leads to a deficiency of the enzyme aldolase B. Not only does HFI cause various symptoms, but it also can cause a buildup of fructose that can lead to liver damage or liver failure.
When malabsorbed and fermentable fructose is in the large intestine, gut bacteria begin to essentially feed on it. The result of this series of chemical reactions is a set of symptoms that is similar to those of another condition called irritable bowel syndrome (IBS), a functional gastrointestinal disorder that disrupts the normal digestive process. In the case of fructose malabsorption, there a several common symptoms:
Like other types of food intolerance (lactose, gluten, sucrose), fructose malabsorption affects different people in different ways; some may experience very mild symptoms while others may have more pronounced and debilitating symptoms. Moreover, most of the associated symptoms can overlap with other digestive disorders; as a result, it can be difficult to diagnose the condition without consultation with a doctor.
For those with fructose malabsorption, managing the condition often goes beyond simply avoiding it because there are so many fructose-containing foods. Most fruits (especially dried fruits) have fructose, but a number of vegetables are also high-fructose foods; examples include artichokes, asparagus, broccoli, leeks, mushrooms, and onions. Most strategies for treating this condition involve some of the following common methods:
In recent years, researchers have been looking more closely at fructose and any impact it may have on metabolism and body weight. Some research has suggested that fructose may stimulate hormones related to weight gain or even fool the body into thinking you’re hungrier than you really are. It’s unclear so far the extent to which this is true, but there may also be other indirect connections between fructose and body weight:
Losing weight can be a challenge for almost anyone, and it can be even harder while managing a gastrointestinal condition. If you’ve tried to lose weight in the past but weren’t able to have success, you’re not alone. At True You Weight Loss, we are passionate about helping people turn the corner and finally find the freedom they’ve been looking for. To find out more about your endobariatric weight loss options, please contact us today to request a consultation.