How does fructose intolerance manifest itself?

In the case of fructose intolerance, the body cannot absorb fructose properly or completely, which in turn can lead to intestinal discomfort.
After eating fruit, fruit juices and other foods containing fructose, various symptoms can occur. These often include flatulence or diarrhea. Those affected also complain of abdominal pain, bloating, belching or nausea. The symptoms manifest themselves differently in each person. In addition, it always depends on how much fructose the affected person has ingested and how sensitive their intestines are.

A change in diet can help

A visit to a specialist in gastrointestinal diseases helps to determine whether you suffer from an intolerance and exactly what form of fructose intolerance you have. If a fructose intolerance is detected, a change in diet can help. People who suffer from fructose intolerance often ask themselves what they are still allowed to eat. This varies from person to person, as everyone is different. It is helpful to visit a nutritionist, who will advise those affected individually. It is clear that there is no list of prohibited and non-prohibited foods that applies to everyone who suffers from fructose intolerance. However, some foods contain more fructose than others. Most doctors will advise a dietary change according to the 3-step model. This is as follows:

1st Restriction phase: this is the first phase of the dietary change. It lasts two to four weeks. The purpose of the restriction phase is to follow a strict low-fructose diet and to avoid all foods containing fructose, sorbitol and table sugar. You can already observe whether the symptoms improve. If this is the case, you move on to the second phase.

2nd test phase: In the following six weeks, the exact amount of fructose the person can tolerate is tested. The person's level is slowly approached. This is done by eating one fructose-containing food per day. All observations should be precisely documented - for example, what you ate, when and how much. This allows the doctor to draw better conclusions later.

3. the long-term change in diet: Once you have found out what and how much you can tolerate, a long-term and healthy change in diet is now necessary. This should definitely take into account your tolerance limit with regard to fructose and should now be permanently integrated into your everyday life.

Foods containing fructose

Apples, pears, cherries and grapes are particularly high in fructose. But dried fruit, jam, mangoes and plums also contain a lot of fructose. Beware of fruit juices and soft drinks, which also often contain fructose. Anyone who thinks that fructose is only found in fruit is mistaken. Vegetables also contain fructose. For example in peas, red cabbage, peppers, mushrooms or garlic. However, the fructose content of vegetables is generally lower than that of fruit.

Foods with a particularly high fructose content

• apples
• pears
• cherries
• grapes
• Dried fruit
• jam
• mangoes
• Plums

Vegetables with fructose content

• Peas
• Red cabbage
• peppers
• mushrooms
• Garlic

Foods low in fructose

Cereal products such as bread, pasta or muesli as well as dairy products without added fruit usually do not cause any problems. Potatoes, rice and millet are also suitable. Meat, fish and eggs are also low in fructose. Nuts and seeds, tea and coffee are also digestible. Cooked fruit generally contains less fructose - but only individual testing will help here, as it may or may not be tolerated by you personally, depending on the severity of your intolerance.

Low-fructose products and foods without fructose

• Bread, pasta, potatoes or muesli
• Dairy products without added fruit, i.e. butter, yoghurt or quark
• Nuts and seeds
• Tea and coffee
• Herbs and salads
• Vegetable oils and apple cider vinegar
• Meat, fish and eggs
• Rice, rye, oats, wheat, oats, spelt or millet
• Pseudo-cereals such as amaranth, buckwheat, quinoa
• berries

Do's and don'ts: It is therefore important that you eat more low-fructose foods to avoid abdominal pain or a feeling of fullness. You don't have to restrict your diet at all, as there is a wide range of foods to choose from. You don't need to worry about getting a vitamin C deficiency, for example - berries in particular contain a lot of vitamin C, so vitamin supplements are not normally necessary. Also remember to always check individually which foods are good for you and which are not. Keep a food diary and make a note of any consequences after eating. A pattern can be derived from this later.

Tip: Get the food table for fructose intolerance on your cell phone

There are these forms of fructose intolerance

Fructose intolerance can be roughly divided into three different groups:

1. fructosuria: This is a genetic deficiency of the enzyme "ketohexokinase", which is needed to convert fructose. This results in excess fructose, which is usually simply filtered out by the kidneys and excreted in the urine, often unnoticed by the person affected.

2. hereditary fructose intolerance: This form of fructose intolerance is a dangerous but rare variant. Due to a genetic defect, an enzyme responsible for breaking down fructose (D-fructose-1-phosphate) is disrupted. This leads to an accumulation of phosphate. As a result, the glycose and glycogen metabolism is disturbed, which can lead to hypoglycemia. Symptoms include nausea, cramps and vomiting. If the affected person continues to consume fructose, this can even lead to liver or kidney failure.

3. fructose malabsorption: This is the most common form of fructose intolerance. In contrast to the other two variants, there is no genetic disorder in the liver, but a defect in the small intestine. Here, the transport of fructose is impeded and so at least some of the sugar is not passed on, but remains in the large intestine. This causes flatulence and can lead to changes in the intestinal flora.

Date: 08.07.2020