John Myers
Hidden sugars in food are a problem, doctors and nutritionists agree. In particular, foods enriched with fructose (fruit sugar) are unhealthy in large quantities and are responsible for obesity, fatty liver, and increased blood lipid levels.
Contrary to popular belief, fructose is no healthier than table sugar. On the contrary, it makes you fat in three ways:
- Fructose is converted directly into fat and stored in the fat deposits
- Fructose prevents fat burning while at the same time increasing fat build-up
- Fructose blocks the feeling of fullness.
Why are we eating more and more fructose?
Fructose belongs to the group of carbohydrates and, like dextrose (glucose), is one of the so-called simple sugars (monosaccharides). In terms of calorie count, fructose and glucose are no different: they both provide four kilocalories per gram.
However, pure fructose is twice as sweet as pure glucose. It is therefore particularly popular in the food industry for sweetening – often in the form of fructose-enriched corn starch syrup. Fructose is also cheaper to produce than table sugar and has a flavor-enhancing effect.
Fructose in fruits and vegetables is better for the body
Fruits also contain fructose, and it is found in almost all types of vegetables – but in much smaller quantities than fruit. Examples of the fructose content per 100 grams of fruit/vegetables:
- Apple: 6 grams
- Grapes: about 8 grams
- Raisins: 33 grams
- Broccoli: about 1 gram.
However, fructose is not the same as fructose. It is crucial for the human body whether it is delivered in the form of a fruit or as part of a chocolate bar, ready meal, or sweetened drink.
The fructose content of fruit juices is significantly higher than that of unprocessed fruits because they lack fiber. In general, fresh and natural foods are preferable to industrially produced ones, as they also contain valuable components such as fiber, phytochemicals, vitamins, and minerals. Special care should be taken with sweetened beverages. So-called functional food, such as wellness drinks, sometimes contain very large amounts of fructose, up to 40 grams per liter.
How fructose works in the body
Sugar is the main fuel in our cells. However, the body cells prefer glucose for energy production. Glucose moves quickly from the blood into the cells with the help of the hormone insulin. It is introduced there actively, i.e. while consuming energy. Fructose, on the other hand, can only be used indirectly for energy production. Even in the intestines, people absorb it to varying degrees and, above all, more slowly than glucose: It flows passively and without energy consumption from the intestines along a concentration gradient into the cells of the intestinal mucosa, from where it gets into the blood. It travels with the blood to the liver, where it is converted into fat. Much of the fat that is produced in this way returns to the bloodstream. It increases blood lipid levels and is stored in fat deposits. A part is also stored directly in the liver.
Excessive fructose consumption and the consequences
Studies have confirmed that increased fructose intake has an unfavorable effect on the metabolism and promotes the development of overweight and obesity as well as dyslipidemia and type 2 diabetes. In addition, the increased intake of fructose increases the risk of high blood pressure. A study by the German Institute for Nutritional Research, which was carried out on mice, has also proven the connection between fructose consumption and obesity. It is based on influencing the fat and carbohydrate metabolism. A study on humans showed that the body converts fructose into body fat much faster than glucose.
