Fructose Malabsorption - Causes, Symptoms, Diagnosis, and Management

Introduction

Fructose is a sugar called a monosaccharide and is primarily found in fruits and some vegetables. People with fructose malabsorption develop signs and symptoms of the disorder when juices, fruits, and other fructose-containing foods are introduced into their diet.

What Is Fructose Malabsorption?

Fructose malabsorption is commonly known as dietary fructose intolerance. The pattern of inheritance of this disease is autosomal recessive. The incidence of fructose malabsorption is one in 20,000 to 30,000 individuals worldwide. The sugar fructose is intolerant by the affected individual, and they may experience bloating, nausea, low blood sugar, vomiting, abdominal pain, and diarrhea. Repeated and frequent ingestion of fructose-containing food can lead to kidney and liver damage in individuals. Also, continuous exposure to fructose can further result in coma, seizures, and death resulting from kidney and liver damage. People with hereditary fructose intolerance often dislike juices, fruits, and foods containing fructose.

Is Fructose Bad for Health?

The two primary components of added sugar include fructose and glucose. Experts have suggested that fructose is more harmful than glucose if consumed excessively. Some people cannot absorb fructose, and this condition leads to digestive discomfort and excessive gas. Fructose causes a low rise in blood sugar levels. It is reported that fructose is a safe sweetener in people with type 2 diabetes. An excessive amount of fructose causes metabolic disorders. Fructose and glucose are metabolized differently in the body. General guidelines for fructose malabsorption include:

• Limit the intake of candies, baked foods, and foods made with HFCS (High-fructose corn syrup). One can have these sweets with a meal and not as a snack.

• Eat fruits in moderation, and include them with the meal.

• Avoid eatables with ingredients that include crystalline fructose, fructose, and honey on their label.

• Limit the drinks that contain HFCS to 4 to 8 oz at a time. Try to drink them with the meal.

• Choose sugar-free drinks.

• Eat gluten and wheat-free bread.

What Are the Harmful Effects of Fructose?

Excessive fructose consumption is very unhealthy, and it causes metabolic disorders. The harmful effects of fructose are:

• Increased uric acid levels increase, which can lead to high blood pressure and gout.

• It is responsible for fat deposition in the liver, leading to nonalcoholic fatty liver disease.

• Fructose raises VLDL (very low-density lipoprotein) cholesterol, which leads to fat accumulation around the organs and also can lead to heart disease.

• Rose can cause insulin resistance, leading to type 2 diabetes and obesity.

• Fructose does not suppress appetite like glucose, which can lead to overeating.

• Excessive fructose consumption causes leptin resistance which disturbs body fat regulation.

What Are the Causes of Fructose Malabsorption?

Fructose malabsorption is common, and it affects one out of three people. The fructose carriers are found in the intestine (enterocytes) cells responsible for the functioning and regulation of fructose. In case of deficiency of these carriers, the fructose then gets stored in the large intestine, resulting in gut issues. There are many causes of fructose malabsorption that, including:

• Increased intake of processed and refined foods.

• In the gut, there is an imbalance of good and bad bacteria.

• Stress.

• Inflammation.

• Preexisting gut issues like irritable bowel syndrome.

What Are the Symptoms of Fructose Malabsorption?

The symptoms of fructose malabsorption include:

• Bloating.

• Nausea.

• Gas.

• Abdominal pain.

• Vomiting.

• Chronic fatigue.

• Malabsorption of certain nutrients like iron.

• Mood disorders like depression and anxiety.

What Are the Risk Factors of Fructose Malabsorption?

Having certain gut disorders like irritable bowel syndrome, Crohn's disease, celiac disease, or colitis can increase the risk for fructose malabsorption or intolerance.

How Is Fructose Malabsorption Diagnosed?

The hydrogen breath test is the most widely used to diagnose fructose malabsorption. This test does not involve a blood draw. Before the test, it is advised to limit the carbohydrate intake the night before and the morning before. The test lasts about three hours, the doctor gives a high fructose solution to drink, and the breath is analyzed every 20 to 30 minutes. If the fructose is not absorbed, it produces a high amount of hydrogen in the intestine. This test determines the amount of hydrogen in the breath from this malabsorption. Also, eliminating fructose from the diet can help diagnose one’s symptoms, whether they resolve or not. Everyone has different tolerances for fructose; some may have less, while others may have more severe.

How Is Fructose Malabsorption Managed?

Managing fructose malabsorption includes the elimination of sugar. Eliminating the sugar that contains a high sugar level can be a good start. They include:

• Honey.

• Soda.

• Pear juice.

• Apple cider and apple juice.

• Sugar snap peas.

• Desserts such as candy, cookies containing fructose sweeteners, and ice cream.

• Sugar alcohols.

• Agave nectar.

• Fructose.

• High fructose corn syrup.

• Crystalline fructose.

• Sorbitol.

• Fructooligosaccharides.

A FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet can be beneficial in managing fructose digestion problems. The FODMAP means fermentable oligo-, di-, monosaccharides, and polyols, and it includes fructans, fructose, lactose, polyols, lactose, and galactans. In a few cases, people with fructose malabsorption may also not tolerate the fructans found in wheat, artichokes, onions, and asparagus.

What Are the Complications of Fructose Malabsorption?

The severe complications that are associated with hereditary fructose intolerance are:

• Liver failure.

• Gout.

• Bleeding.

• Low blood sugar.

• Death.

Conclusion

Fructose malabsorption depends from person to person, so the treatment will. Whether one has a mild or severe case of fructose malabsorption, a low FODMAP diet or a fructose elimination diet may be beneficial.Consulting a dietician can be helpful as they can support the development of a plan accordingly.