Hereditary Fructose Intolerance (HFI) is quite rare (less than one in 10,000). It is inherited (genetic) so you have it for life. A positive diagnosis requires a stool test (DNA test) from your doctor.

Fructose Malabsorption is very common. Up to one in three people or 33% has some level of sugar sensitivity - most commonly to Fructose. However around half of these people may show no symptoms at all - until later in life. Fructose is found in some fruits and vegetables, and thousands of processed foods like soft drinks and confectionery.

Most sensitivity to sugars like lactose, fructose and sorbitol is undiagnosed, but can be responsible for unexplained stomach bloating, diarrhea and intestinal distress in millions. These sugars are used extensively in manufactured foods due to their sweetening power and low cost.

If you think you might have Fructose sensitivity - compare your symptoms in the Symptoms Matrix

Hereditary Fructose Intolerance (HFI) is a rare genetic condition where the enzyme for breaking down Fructose is not produced. If you discover you have fructose sensitivity - you need to rule out HFI by seeing your doctor for a DNA test. With HFI it is vital to observe a very strict Fructose-free diet. Otherwise there is risk of serious disease including liver failure.

Fructose malabsorption on the other hand is much more common and affects about 30% of people. It especially affects young people who have many soft drinks per week including soda and mixers. With Fructose Malabsorption special cells (epithelial cells) on the surface of the intestine are not available to break down the fructose sugars.

Comments: Treatment of HFI is a very strict Fructose-free diet for life. Treatment for Fructose Malabsorption is a Fructose-free diet with some concessions. You find a threshold level where you can eat some Fructose without getting symptoms. Sign up for the Symptoms Matrix to compare your symptoms.

Symptoms for both types:

• Gastro-intestinal distress: flatulence, bloating, diarrhea

• Tiredness, Chronic fatigue

• Malabsorption issues: low iron (anaemia), osteoporosis or other nutrient deficiency

• Sugar cravings

• Poor skin, nails and hair

• Irritable Bowel Syndrome

• • For Fructose Sensitivity (the more common type) there is clinical evidence associating it with mood disturbances and depression.

Comments: The symptoms of both types of Fructose sensitivity are very similar to Lactose Sensitivity so they can be mistaken for one another. You cannot diagnose your food sensitivity from symptoms alone. To differentiate among them it's best to keep notes in a simple Journal (free to subscribers).

The hydrogen or H₂ breath test is often used. However this test is not reliable - and almost always returns a positive result. The doctor may also use stool analysis to check for HFI. If you find you are Fructose-sensitive it is vital to rule out HFI as there may be serious health issues.

You can partly identify Fructose sensitivity by comparing your symptoms in the Symptoms Matrix . However the most reliable and accurate test is the Elimination Diet (Journal Method).

Comments: A simple Journal identifies the offending food - whether it is Fructose, Lactose or something else. It is important to keep a journal because reactions can be delayed up to 3 days.

It is genetic – so you got it from your parents and grandparents. A very small percentage of people have the hereditary Fructose Sensitivity (less than 1 in 10,000 people.)

Most Fructose sensitivity is the Malabsorption type. It may be somewhat self-imposed by our modern sugar-heavy diets. Humans have not yet evolved systems to cope with such high sugar consumption.

Comments: Consider the high level of sugars like fructose we ingest: in soft drinks, confectionery, desserts, cookies and thousands of processed foods and pharmaceuticals. Fructose sensitive people improve dramatically on a Fructose-free Diet.

A Fructose-free or low-sugar diet is the best treatment - and the best management - forlife. This is easy if you know which foods contain fructose - but many processed foods contain added Fructose under aliases like 'corn syrup'. You need a guide.

Comments: Fructose is present in many fruits and vegetables and thousands of processed foods, supplements and medications.
For guidance on how to follow a Fructose-free diet, see the Complete Guide to Fructose-free

The rare HFI (Hereditary Fructose Intolerance) cannot be cured. For this a strict Fructose-free Diet must be maintained in the long term.

The much more common Fructose Malabsorption cannot be cured either. But it is much easier to manage. Using a journal and monitoring yourself, you will find a threshold level that is easy to live with. That is - you will be able to eat some Fructose without suffering symptoms.

Comments: It is important to keep a journal of food eaten and symptoms on a daily basis, until you come to know your body's limits. A Journal lets you discover your threshold of sensitivity - so you can eat some sweet foods without suffering symptoms.