Fructose is a type of natural sugar that can be found in fruits, vegetables, and honey. Fructose malabsorption, also known as dietary fructose intolerance, occurs when cells on the intestine’s surface are unable to effectively break down fructose. Fructose malabsorption has also been proposed as a possible cause of irritable bowel syndrome (IBS). Fructose malabsorption is thought to affect one in every three IBS patients and is caused by incomplete fructose absorption in the small intestine, resulting in gastrointestinal complaints.
Eating foods high in fructose can cause unpleasant symptoms in those with dietary fructose intolerance, such as gas, bloating, diarrhea, and stomach pain. Dietary changes are the most common way to address gastrointestinal complaints such as IBS. A common diet change is the low-fermentable oligo-, di-, monosaccharide, and polyol (FODMAP) diet. This is a restrictive diet designed to limit the carbohydrates that are poorly absorbed in the small intestine and are then fermented by intestinal bacteria.
People with fructose malabsorption should avoid the following foods:
- Sweeteners like honey, dates, sugar, coconut sugar, maple syrup, molasses, agave nectar.
- High-fructose fruit like raisins, pear, watermelon, mangoes apples, and grapes.
- High-fructose vegetables like artichoke, asparagus, broccoli, leeks, mushrooms, okra, onions, peas, red pepper, shallots, and tomato products.
- Artificial sweeteners, such as sorbitol, which can be found in several diet drinks and foods.
- Fruit juices
- Soda
According to the USDA database, foods with more fructose than glucose include:
| Food | Fructose (grams / 100 grams) | Glucose (grams / 100 grams) |
|---|---|---|
| Apples | 5.9 | 2.4 |
| Pears | 6.2 | 2.8 |
| Fruit juice e.g. Apples, Pears |
5–7 | 2–3 |
| Watermelon | 3.4 | 1.6 |
| Raisins | 29.8 | 27.8 |
| Honey | 40.9 | 35.7 |
| High fructose corn syrup |
42–55 | 42–53 |
| Mango | 4.68 | 2.01 |
| Agave nectar | 55.6 | 12.43 |
| Ginger | 1.78 | 1.22 |
Dietary guidelines for treating fructose malabsorption, specifically for those with IBS, were created by researchers at Monash University in Australia.
Favorable Foods (fructose equal to or less than glucose)
- Stone fruit: apricot, nectarine, peach
- Berry fruit: blackberry, boysenberry, cranberry, raspberry, strawberry, loganberry
- Citrus fruit: kumquat, grapefruit, lemon, lime, mandarin, orange, tangelo
- Other fruits: ripe banana, jackfruit, passion fruit, pineapple, rhubarb, tamarillo
Unfavorable Foods (more fructose than glucose)
- Fruit: Apple, pear, honeydew melon, nashi pear, pawpaw, papaya, quince, star fruit, watermelon
- Dried fruit: Apple, currant, date, fig, pear, raisin, sultana
- Fortified wines
- Foods containing added sugars, such as agave nectar, some corn syrups, and fruit juice concentrates