Fructose is a single sugar or a monosaccharide which is often referred to as fruit sugar. It is similar to glucose but has a different molecular structure. Additionally, it is much sweeter than glucose but has same calorie content. It is possible to live without any fructose content in the body and hence it is not an essential nutrient.
Fruits, wheat, sugarcane, some vegetables, honey and sugar beets have fructose naturally occurring in them. Commercial drinks and foods can also have fructose that either occurs naturally or is added in the form of a sweetener.
It is not possible for the human body to absorb unlimited quantities of fructose. Most individuals can intake 20 to 25 grams of fructose per meal. The inability of an individual to consume even 25 grams of fructose per meal can be considered as fructose malabsorption. Bloating and diarrhea are some of the side effects of unabsorbed fructose
The unabsorbed fructose sucks the water from the intestines and travels to the colon. Here, the bacteria break it down into gases and short chains of fatty acids, which eventually lead to bloating and diarrhea
Fructose malabsorption is completely different from allergic reactions and does not result in typical allergic symptoms such as hives or itching.
Symptoms of fructose malabsorption
An explanation of fructose malabsorption and its various symptoms are given below:
- Fructose malabsorption is different from hereditary fructose intolerance which is a rare genetic abnormality. Individuals with hereditary fructose intolerance do not have the enzyme which is required to break down fructose. This disorder is generally diagnosed at an early age and result in serious health consequences such as kidney and liver damage
- On the other hand, fructose malabsorption is not so serious and can be detected at any age.
- The symptoms for fructose intolerance may show up either within a few hours after consumption of meal that contains fructose, or after 24 hours. Some individuals may experience the symptoms after consuming around twenty grams of fructose, while others may have a fructose threshold of only one gram.
- Some of the most common symptoms of fructose malabsorption include diarrhea, bloating, pain in the abdomen, gurgling as well as increased instances of flatulence.
- Some individuals may also develop an aversion to foods that taste sweet.
- On rare occasions, some patients may show other symptoms such as loss of weight, anxiety, headaches, depression, fatigue and increased cravings for sugar.
- Fructose malabsorption leads to diarrhea. This results in the flushing out of some vital nutrients such as vitamins and iron from the body before they are absorbed by the intestine. This may eventually cause other abnormalities such as nutrients deficiencies, anemia and other health conditions
Causes of fructose malabsorption
There are several causes of fructose malabsorption. Some of the causes are discussed below:
- Fructose malabsorption can affect anyone, right from infants to older individuals. Some of the possible causes of fructose malabsorption are discussed below:
- Some cases of fructose malabsorption may be acquired or inherited from the either of the parents who have an abnormality of GLUT-5, the fructose transporting protein. In such cases, other family members may also be affected by the condition.
- The overgrowth of bacteria in the small intestine or SIBO can also lead to fructose malabsorption.
- Excessive intake of fruit juices by children or the increased intake of HFCS or High Fructose Corn Syrup by infants may result in toddler’s diarrhea
- Individuals with the dumpling syndrome that results in quick emptying of the stomach or the presence of celiac disease can also result in development of the condition.
- Medical therapies such as radiation therapy or chemotherapy that damages the linings of the small intestine can lead to fructose malabsorption
- It is important to note that the Glucose-to-Fructose ratio should be sufficient to prevent symptoms of the condition. This is due to the fact that one molecule of glucose is responsible for absorption of one molecule of fructose. Thus an equal Glucose-to-Fructose ratio actually enhances the absorption of fructose from foods, even in individuals who are affected by fructose malabsorption.
Treatment of fructose malabsorption
As of now, there is no treatment for fructose malabsorption. However, one can effectively avoid the symptoms of the condition by controlling the diet to include food items that are low in fructose or altogether avoid those items that contain fructans, fructose and sorbitol.
However, it is important for the affected individuals to consume the requisite amount of nutrients. Hence, one must consult a dietician who can help prepare a complete list of foods that should be avoided. Also, the dietician can assist in the preparation of a diet plan that will include all the vital nutrients required by the body.
Some of the foods that the affected individuals can limit or avoid are listed below:
- High-fructose corn syrup
- Powdered sugar
- Sweetened milk beverages or sweetened milk
- Table sugar
- Fruit juices and fruits
- Regular sodas
- Honey
- Flavored water
- Sports drinks
