Fructose Malabsorption: The Only Guide You Need
What is Fructose Malabsorption?
- Fructose malabsorption is a condition where the small bowel struggles to absorb the fructose that we eat, potentially causing symptoms like bloating.
Fructose Malabsorption (continued):
Fructose malabsorption is a digestive disorder in which proper absorption of fructose does not take place in the small intestine.
This poorly absorbed fructose moves through to the large bowel, where it gets fermented by the flora present in the intestinal tract.
The fermentation by bacteria produces gas and other gastrointestinal symptoms.
As our body does not require digestive enzymes to digest and absorb fructose in small intestine.
In normal, healthy persons, only about 25-30 grams of fructose are absorbed at one time. However, in case of people with fructose malabsorption, less than 25 grams of fructose is absorbed at any given time.
This inadequately digested fructose reaches large intestine where it combines with water due to its osmotic effect. Here, it is rapidly propelled into the colonic lumen where luminal bacteria ferment fructose to carbon dioxide, hydrogen and short chain fatty acids.
This leads to physiological consequences, including increase in osmotic load, change in gastrointestinal motility, alteration in gastrointestinal flora, and rapid bacterial fermentation. The clinical significance of these events varies from individual to individual depending upon the response of the bowel to such changes.
Formerly known as dietary fructose inheritance, Fructose malabsorption is completely different from fructose intolerance.
Fructose intolerance is a rare, hereditary disease in which the liver enzymes that break down fructose are deficient. If left untreated, it can be a potentially fatal condition.
Its estimated that nearly 35 percent of the population struggle to absorb fructose properly, but before we understand more about fructose malabsoprtion - we need to understand what Fructose is!
What is Fructose?
- Fructose is a naturally occurring sugar found in honey, vegetables, fruits and grains.
It is a single molecule sugar which many people cannot effectively absorb. This poorly absorbed small carbohydrate act as dietary fibre or prebiotics, also known as FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols).
Other poorly absorbed sugars included in FODMAPs are lactose, sorbitol, fructans, galacto-oligosacchrides and mannitol.
When the fructose sugar is not properly absorbed in the small intestine, it reaches large intestine where fermentation occurs, and fructose is converted in to fatty acids.
These fatty acids cause gastrointestinal symptoms like bloating, gas, constipation and diarrhea.
What are the Symptoms of Fructose Malabsorption
- The symptoms of fructose malabsorption are actually similar to those of lactose intolerance, food allergies and irritable bowel syndrome. Common symptoms observed immediately after consumption of fructose-rich foods are:
- Bloating and distension
- Diarrhea or constipation
- Fatigue or tiredness
- Stomach pain or indigestion as a result of muscle spasm
- Brain fog/ negative emotions
- Nausea or vomiting if large quantities of fructose are consumed
Long term fructose malabsorption symptoms can include:
- Craving for sugar, and in rare case aversion to sugar
- Poor absorption of minerals and vitamins, resulting in anaemia, malabsorption and poor general health.
- Difficulty in gaining weight
- Early signs of mental depression
- Poor nails, skin and hair
- Osteopenia or osteoporosis, caused due to high fructose levels in the diet.
How to Diagnose Fructose Malabsorption
- The hydrogen breath test is the fundamental diagnostic test for assessing the identification of dietary fructose malabsorption.
This simple and non-invasive method is a reliable way to diagnose fructose malabsorption.
How does the fructose test work?
The patient is asked to drink 25 to 30 grams of fructose (dissolved in water) on an empty stomach.
Hydrogen levels are measured in the exhaled air for the next three hours.
Hydrogen can only be found in the exhaled air if the fructose is not entirely absorbed by the body.
Hydrogen is released when the bacteria ferment the poorly digested fructose in the large intestine.
The produced hydrogen reaches the lungs via the circulatory system, where it is exhaled into the testing device.
If you suspect that you have Fructose Malabsorption, you should go speak to your doctor about obtaining a refferal for a hydrogen breathe test. You will most likely be referred to complete a lactose test as well ( I was). The hydrogen breathe test will most likely be completed at your local hospital or specialist testing clinic.
Otherwise there are a range of home testing kits for fructose (and lactose) malabsorption that you can purchase online, complete in your home and have the results tested by a laboratory. I've included a list of online fructose testing laboratories below:
Online Fructose Test Kits:
- Quintron Fructose Home Breathe Test kits - Home Breathe test kits for fructose malabsorption detecion.
- Commonwealth Laboratories - You need to have a prescription to order the lactose test, but you seem to be able to get the fructose test without. They also have a product for Canadian residence.
- GastroLab Gut Diagnosis - Offer a range of test kits posted to anywhere in Australia.
The other method for diagnosing the symptoms of fructose intolerance is by following an elimination diet. A diet whereby the patient must elimate all foods containing fructose for 6 weeks. If the symptoms disappear after eliminating fructose containing foods from the diet, fructose malabsorption is confirmed.
What is Fructose Malabsorption Treatment -How do I fix Fructose Malabsorption?
- The treatment for fructose malabsorption is the low FODMAP diet.
- Fix Your Digestion program by Dr Jillian Teta - onlin diet plan to guide you through the low FODMAP diet. Handy if you don't feel you can stick to the low FODMAP diet on your own.
There is no permanent cure for fructose malabsorption, but the condition can be managed by limiting the amount of fructose that is consumed.
The goal of the treatment is to eliminate or drastically reduce symptoms, restore normal digestion and maintain subsequent health and longevity.
Once you are symptom-free for months, you can gradually reintroduce small amounts of foods that previously caused problems.
The dietary strategies to assist with minimising symptoms include:
- Avoid foods containing excess fructose;
- Reduce the fructose load; and
- Avoid foods that contain fructans (Fructans are chains of fructose molecules which end in a glucose molecule).
Foods that should be avoided by people with fructose malabsorption include:
- Foods containing more than 0.5 grams of fructose per 100 grams of glucose.
- Foods containing more than 0.2 grams of fructans per serving.
- Foods with high fructose to glucose ratio higher than 1.0
- Foods rich in sorbitol
- Foods containing high amounts of fructose content like corn syrup.
So what food is low in Fructose?
- Below, we have compiled a list of foods that most people with Fructose Malabsorption find "Okay to eat" and the foods that are "Best to avoid" eating completely avoided. Please keep in mind that this list is not extensive and should only be used as a starting point to finding the foods that are causing symptoms of Fructose Malabsorption. Different people will find that they have different tolerances to different food types.
Fructose Malabsorption Food List for Low FODMAP diet
Okay to eat
Best to avoid
|Potatoe, Carrot, Celery, Olives, Corn, Cucumber, Lettuce, Spinach, Tomatoes||Onions, Garlic (enemy #1 for me!), Artichokes, Beetroot, Cabbage, Fennel, Leeks, Peas, Spring Onions|
|Lemon, Lime, Banana, Blueberries, Oranges, Grapes, Passionfruit, Raspberries, Strawberries||Apples, Pears, Cherries, Mango, Honey, Peaches,|
|Beef, Turkey, Pork, Chicken, Lamb, Veal, Fish||Processed Ham, Bacon and other small good varieties (check the packaging but these meats are often manufactured with sugar or honey).|
|Gluten-free bread, Corn Tortillas, Rice Noodles, Rice Puffs, Gluteen-Free Crackers, Rice||Bread, Pasta, Wheat Based Breakfast cereals, Wheat Based Crackers, Wheat Sweet Buiscuits|
|Milk (if you do not have problems with lactose), Coffee (although test this, I can't have it at all!), Tea, Mineral Water, Unsweetened Cranberry juice, Water||Fruit Juice, Vegetable Juice (check for best to avoid vegetables), Soda, Sweetened Drinks, Drinks containing High Fructose Corn Syrup,|
|Vodka from grain or potatoe is generally the safest. Gin, Whiskey, Rum and Dry White Wines should also be okay in small amounts. I find that I can have Corona Beers and I don't get too bloated.||Beer, Red Wine.|
Note - if you are changing diet to manage your fructose malabsorption intolerance you should do so with the supervision of a dietician who has experience with IBS symptoms. This will ensure that you are receiving the right amount of nutrients and vitamins in your diet.
A full list of foods that contain fructose can be found here - Food Standards Australia. Please keep in mind that foods with fructose to glucose ratio of less than 1, should be fine to consume.
The most useful book for people who are following the Low-FODMAP diet is by Australian doctor Sue Shepherd.
It contains information about Fructose Malabsorption and sample meal plans for you to use.
If you have any question or comments, please leave your comments below, I'd love to hear about what your experience with Fructose Malabsorption has been!
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