Fructose intolerance - causes, symptoms and dietHealthy you eat, you eat fruits and vegetables, but still you feel bad? If ever you are struggling with problems such as bloating, diarrhea, headache, abdominal cramps and gas, you may be suffering from fructose intolerance.
What is fructose?Fructose is a monosaccharide (i.e., a simple sugar), in which food can occur in three different forms: as free fructose, as part of sucrose (table sugar which we use to sweeten) and as a component of oligo- and polysaccharides (fructans).
Fructans are not decomposed in the intestines only in the large intestine (specifically, colon) are metabolised by the bacteria. The result is the formation of short chain fatty acids, hydrogen and carbon dioxide. Consuming excessive amounts of fructans may at any cause discomfort such as nausea, diarrhea and flatulence.
Free fructose means that a molecule of fructose is linked to a chemical bond with another molecule of sugar. Fructose, known as fruit sugar, is present in fruits and vegetables.
Fructose bound glucose are sucrose, or table sugar, in short referred to simply as sugar. Sucrose consists of one molecule of fructose and one glucose molecule. During digestion of linkage between glucose and fructose is torn to form the free molecule of glucose and free fructose molecule. Only in the form of sugars can be absorbed by our body. Fructose is absorbed in the small intestine by means of conveyors GLUT5 and the glucose transporter GLUT2 with and SGLT-1.
What really is fructose intolerance?In case of intolerance to fructose transporter GLUT5 they operate only partially. Free fructose can not be absorbed into the body, however, together with other undigested debris gets into the large intestine (colon), where the bacteria are waiting for it. These bacteria, as in the case of fructans, metabolize fructose to short chain fatty acids, carbon dioxide and hydrogen.
Hydrogen does not cause any symptoms of the intestinal wall gets into the bloodstream and is excreted through the lungs. It is this hydrogen is used in hydrogen respiratory test, used for diagnosis of fructose intolerance and lactose. Other metabolites (fatty acids, carbon dioxide) are responsible for bloating, headaches and abdominal cramps, nausea, gas and diarrhea.
Undiagnosed and untreated fructose intolerance can also lead to chronic constipation, nutritional deficiencies (mainly zinc and folic acid) and even non-alcoholic fatty liver disease.
Hereditary fructose intoleranceOf fructose intolerance must be distinguished fructosemia, or congenital fructose intolerance. It is a hereditary disease involving the lack or severe deficiency of aldolase fructose-1-phosphate. It is the enzyme involved in the metabolism of fructose in the liver.
In this case, fructose is easily absorbed from the small intestine to the body, but can not be properly metabolized by the liver. Fructosemia disclosed in infants introducing into the diet products containing fructose (the mother's milk does not contain any).
This disease is manifested by severe hypoglycemia, vomiting, hepatomegaly, jaundice, hemorrhages. Hereditary fructose intolerance requires total exclusion of fruit sugar from your diet. Remaining un-fructose leads to liver and kidney damage, and lead to the death.
Diet with fructose intolerance - what you can not eat?Products to be absolutely eliminated from the diet are:
- small seeds fresh fruit (apples, pears, melons, papayas, watermelons);
- dried fruit (apples, plums, apricots, figs, dates, raisins);
- formed on the basis of fruit preserves (jams, mousses, marmalade, syrups);
- fruit and vegetable juices;
- vegetables: green peas, carrots and parsley, potatoes, cucumbers, radishes;
onions, beans, peas and beans. These vegetables are defined as permitted in small quantities.
dairy products enriched with fruit and fruit flavors: fruit yogurt, fruit curd, buttermilk fruit, fruit whey, milk flavored;
agave syrup and maple syrup;
wheat and barley;
and all other products, the manufacture of which table sugar (sucrose).
Diet with fructose intolerance - you can eat?
- natural dairy products such as milk, curd, buttermilk, yogurt, curdled milk, cheese (although in this case, better to first read the label);
- vegetables - asparagus, spinach, lettuce, celery, cauliflower and root vegetables - with the exception of carrots and parsley (especially cooked), potatoes, cucumbers, radishes. In small quantities, you can eat tomatoes and squash;
Patients with malabsorption of fructose can reach the fruit lower fructose and those in which fructose is balanced with adequate glucose, ie.
- citrus (grapefruit, oranges, lemons, kumquats, mandarins);
- fresh fruit coarsely stone fruit (apricots, plums, peaches, nectarines);
- berries (blueberries, cranberries, raspberries, strawberries);
- other fruit: ripe bananas, kiwi, pineapple;
However, you should eat them in small quantities and never on an empty stomach. In addition, people with malabsorption of fructose can drink fruit juice diluted with water 1: 1 ratio.
If a baby is fed artificially (milk replacers), should only be chosen blend of free fructose and sucrose.
Where it can be hidden fructose?
- sauces, mustards, ketchups
- marinades for meat and fish
- soup bags
- flavored milk
- bread (especially hamburger buns, toast)
- drugs (both coated tablets and syrups)
- dietary products
- products for diabetics
Fruit sugar can also hide in products with additives on the label marked "E" symbol: E420: sorbitol, E473 and E474: esters of carbohydrates, E491-E495: sorbitan esters may liberate sorbitol.