A diet for fructose intolerance

Fructose intolerance (fructose malabsorption or intestinal fructose intolerance)

If you have been diagnosed with fructose malabsorption (intestinal fructose intolerance), the therapy takes the form of a change in diet over three phases.

Whereas sufferers with hereditary fructose intolerance must forego fructose entirely in the long term, the diet of persons with intestinal fructose intolerance must not be based around the pure fructose content of food. Although the symptoms initially improve if fructose is strictly avoided, they worsen in the long term because the transporter in the intestine reduces its activity even more as a result of the period of adaptation.

In some sufferers, certain conditions can improve fructose tolerance. When fructose is consumed with glucose in a ratio of 1:1, the fructose is tolerated better. Fat and protein further improve the transport because they extend the time that the food spends in the stomach. Foods with a high proportion of protein or fats therefore have the effect that only small amounts of fructose reach the small intestine.

The change in diet takes place over three phases.

1st phase: Period of adaptation to reduce symptoms:

• Eat less food with a high fructose content, such as apples, pears and dried fruit
• Don't eat foods that easily cause bloating
• Use glucose instead of normal sugar as this improves fructose transport
• Avoid sugar alcohols such as mannitol or sorbitol etc.
• Ensure a sufficient intake of vitamins because many types of fruit and vegetables will be off the menu

This phase should last for a maximum of 2-4 weeks.

2nd Phase: Test phase - extending the choice of foods and paying attention to a moderate fructose intake:

• When you increase fructose intake again, the individual tolerance limit varies and everyone must test out for themselves what that limit is
• Above all, you should eat more of the tolerable types of fruit
• Sugar should still be combined in the meals along with fat and protein
• Aim to eat more vegetables than fruit
• Continue to avoid sugar alcohols
• Cabbages and carbonated drinks can also be tried to see if you can tolerate them
• Now you can try things like wholegrain bread and pastries, melons, citrus fruits, apricots, pulses, peaches, sweets, cakes, coffee and wine. Foods that can be tolerated in this phase include bananas, mandarins, non-swelling varieties of vegetables, pasta, potatoes, rice, meat, fish, eggs, bread made from finely ground grain, sweets with glucose and still mineral water, herbal tea, beer and spices.

This phase can last up to 6 weeks.

3rd phase: A long-term diet:

• All foods that you can tolerate can be eaten without any worries. The goal is long-term freedom from symptoms
• A balanced intake of nutrients should be ensured, so eat as varied a diet as possible and drink sufficiently
• After a while, try out some other foods because in some cases the absorption capacity of fructose improves again, i.e. your tolerance limit increases

When changing your diet, enlist the support of a nutritional specialist who has been trained in the treatment of allergies. They can help you with your individual daily plans and menus, and thereby prevent a nutrient deficiency associated with fructose intolerance.

Glucose improves the absorption capacity of fructose, so you should always have some to hand.

After changing your diet you will know which foods you can tolerate, which at buffets will allow you to put together your own individual meal just as you like it.

If you're unsure about the ingredients of a meal, ask in the kitchen about exactly what's in the dish. If an unsuitable food is in amongst it, you can ask for something else instead or improve the fructose to glucose ratio by adding a bit of glucose.