Hereditary Fructose Intolerance
What is Hereditary Fructose Intolerance?
Hereditary Fructose Intolerance (HFI) is a rare genetic condition that affects how the body processes fructose, a type of sugar found in many foods. People with HFI lack an enzyme (Aldolase B) needed to break down fructose properly. When they eat foods containing fructose, sucrose or sorbitol, it can build up in the body and cause serious health problems, especially in the liver and kidneys.
Fructose is a sugar naturally found in fruits, vegetable and honey. It is also part of the disaccharide Sucrose. Sucrose, also known as table sugar, can also be found in fruits, vegetables, wholegrain cereals and is often added to a wide range of canned and processed foods as a sweetener preservative. Sorbitol is a sugar alcohol commonly used as an artificial sweetener and can also be found in some medications.
For someone with HFI, even small amounts of fructose can make them very sick. When fructose isn’t broken down properly, it can lead to symptoms like:
- Severe stomach pain
- Vomiting
- Low blood sugar (which can cause dizziness, shakiness, and sweating)
- Extreme tiredness
- Liver problems (fatty or enlarged liver)
If untreated, continued fructose exposure can cause serious complications, including liver and kidney damage. That’s why it’s so important for people with HFI to completely avoid fructose, sucrose, and sorbitol in their diet.
HFI is usually diagnosed in infants or young children, when they start eating foods that contain fructose. Symptoms often appear after introducing fruits, vegetables, or sweetened formulas. A doctor may suspect HFI based on symptoms and confirm it through genetic testing or specialised blood tests. In many cases, young children that are undiagnosed will avoid all sweet tasting foods as they make them feel very unwell. It is also possible to be diagnosed with HFI as an adult.
The good news is that HFI can be managed with a strict fructose-free diet. Once fructose is completely removed, most people with HFI can live healthy, happy lives without ongoing health problems.
Living with HFI means:
✅ Reading food labels carefully to avoid hidden sugars
✅ Cooking homemade meals to ensure foods are safe
✅ Working with a multidisciplinary clinical team for ongoing review and support
It is important to note that, due to the rarity of Hereditary Fructose Intolerance, not all healthcare professionals will be familiar with the condition. Because of this, it’s essential to advocate for yourself or your child when it comes to dietary advice and medical care. Always double-check recommendations to ensure they are safe and appropriate for HFI. Many families find support in HFI communities and through shared experiences with others who understand the condition firsthand. I have personally made some wonderful friendships through our HFI community, and it was a big reason why I created my HFI in The Kitchen social media pages, to connect with likeminded people and share our experiences.