For years we have been assured that fructose, unlike regular sugar, is healthy. It was even recommended for people with diabetes. But a study by experts from Weill Cornell College of Medicine and New York Presbyterian Hospital (USA), published in the journal Nature, showed that there may be a relationship between the increase in consumption of fructose worldwide and the increase in obesity and some types of cancer.
Fructose is found in baked goods, breakfast cereals, corn syrup, sauces, and drinks. It tastes sweeter than regular sugar and has a lower glycemic index than glucose. Therefore, the sweetener is included in many dietary products.
American researchers have discovered the mechanism by which fructose disrupts metabolism and causes the body to accumulate fat stores.
The inner surface of our intestines is covered with a huge number of microscopic villi that increase the surface area of the intestines and help the body absorb nutrients from food.
Scientists conducted experiments on mice that were fed foods high in fructose. It turned out that their intestinal villi were 25-40% longer than in mice that were not given fructose. That is, the process of assimilating food went much faster. Accordingly, the mice began to gain weight rapidly.
Once in the intestinal villi, fructose binds to an important signaling protein responsible for cell metabolism, which, in turn, promotes intensive cell growth. Malignant intestinal tumors on fructose feeding also grow more intensively.
But how dangerous is a compound found in almost all sweet berries and fruits? One of the authors of the study, Professor Robert Lustig, explains that we consume natural fruit sugar together with fiber substances – plant fibers that regulate blood sugar levels. The scientist calls these plant fibers “a kind of antidote that prevents an overdose of fructose in the body.”
According to him, “the metabolism of fructose in the body resembles that of alcohol and can cause ailments typical of alcoholism – diseases of the liver and cardiovascular system. Fructose enters the liver and can seriously impair liver function. As a result, this often leads to such serious diseases as metabolic syndrome – an excessive increase in the mass of internal fat, decreased sensitivity of peripheral tissues to insulin, impaired carbohydrate and lipid metabolism and hypertension. “
The researchers concluded that fructose itself is not harmful. This is an overconsumption problem.
Will the results obtained in experimental mice be confirmed in humans? This will be the focus of future research.
Commentary by Tamara Pruntseva, nutritionist, therapist of the Federal State Budgetary Institution “Federal Research Center of Nutrition and Biotechnology”:
– Fructose refers to monosaccharides that are present in free form in foods such as sweet fruits, some vegetables, honey. For a long time fructose was included in the diet for patients with diabetes mellitus, but today it has become clear that the metabolism of this substance is similar to that of glucose. Accordingly, the risks of diseases will be the same as with the use of glucose. The more a person eats sugar or fructose, the more he wants. In such cases, it is possible to wean a person from sugar in a short period of time – 10-14 days, and the receptors will return to their previous perception.
If there is a lot of fructose in the body, then it is processed into fat and enters the bloodstream in the form of triglycerides. Accordingly, there may be risks of increased cholesterol levels, and, therefore, cardiovascular diseases. Added sugars, which include fructose, should be no more than 10 percent of the daily calorie intake. Excessive consumption can lead to weight gain and consequences such as increased blood sugar levels.
There is another danger that fructose is fraught with – a hereditary-genetic disease of fructosemia, which indicates defects in the enzymes in the human body that break down fructose. Fructose intolerance is found in childhood during the introduction of complementary foods in the form of fruits, vegetables, juices, purees. We can diagnose it in blood tests, and the clinical symptoms will be vomiting and diarrhea, lethargy and possible signs of gout.
But fructose also has beneficial properties. Its natural sources are honey, dates, dried fruits. It has a lower glycemic index than glucose, but in any case, the consumption should be moderate. The use of sweeteners in baby food is not permitted.
As for the relationship of fructose with intestinal cancer, then, despite the fact that such studies were carried out, we do not yet have an evidence base.
.