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Nature: The reason why high-fructose drinks make people gain weight has been found. Fructose expands the intestinal surface area, promotes nutrient absorption, and increases weight.
Nature: The reason why high-fructose drinks make people gain weight.In recent years, the rate of human obesity has been steadily increasing. Between 1975 and 2016, the rate of obesity worldwide has tripled, which has brought a huge burden to public health and people’s health. In addition to affecting personal image, obesity also brings various health risks such as cardiovascular disease and cancer. It is estimated that the number of deaths caused by obesity worldwide is as high as 2.8 million every year.
Fructose is a monosaccharide, an isomer of glucose, and the second most abundant sugar in the diet after glucose. Fructose has the advantages of good taste, high sweetness, and low glycemic index. Therefore, it was once regarded as “healthy sugar” and was widely added to beverages and foods to enhance the taste. For example, the sugar added in milk tea that everyone often drinks is mainly fructose.
Although a fat-rich diet is the main cause of increased obesity, excessive consumption of processed sugars, especially high-fructose corn syrup, is closely related to diet-induced obesity. However, whether fructose will cause obesity in humans and how to cause obesity in humans is still debated.
On August 18, 2021, researchers from Weill Cornell Medicine in the United States published a research paper titled: Dietary fructose improves intestinal cell survival and nutrient absorption in the top international academic journal Nature.
In this study, the researchers fed mice high-fructose corn syrup (a sweetener widely used in human diets) to increase the surface area of the intestine, thereby promoting the absorption of dietary nutrients and increasing weight.
Due to the large amount of fructose contained in beverages, candies, and processed foods, people’s fructose intake has increased greatly in recent years, especially in developed countries and regions. Previous studies have shown that fructose consumption is related to the rising incidence of obesity and cancer. Obesity and cancer are important causes of global morbidity and mortality.
However, whether fructose will cause obesity in humans and how to cause obesity in humans is still debated.
The metabolism of fructose in food and beverages begins in the epithelium of the small intestine. Fructose is transported by the type 5 glucose transporter (GLUT5, encoded by the SLC2A5 gene), and is phosphorylated by ketohexose kinase to form fructose 1-phosphate, and accumulates at high levels in cells . Although this pathway is related to obesity and tumorigenesis and development, the exact mechanism of fructose driving these pathologies in the intestine is still unclear.
In this study, the research team fed mice high-fructose corn syrup (a sweetener widely used in human diets) and found that this dietary fructose can increase the survival rate of intestinal cells and increase the intestines in the mouse model. Villi length. The increase in intestinal villi length expands the surface area of the intestine and increases nutrient absorption and obesity in mice on a high-fat diet.
The tip of the intestinal villi is in a hypoxic state because it is far away from the blood vessels, so the intestinal cells are easy to die here, which inhibits the length of the intestinal villi. In hypoxic intestinal cells, fructose 1-phosphate inhibits the M2 subtype of pyruvate kinase to promote cell survival. The research team’s inhibition of ketohexose kinase or activation of pyruvate kinase can prevent the growth of intestinal villi and eliminate nutrient absorption and tumor growth caused by high-fructose-fed mice.
Overall, this study provides convincing data, showing that dietary fructose can improve the survival of intestinal cells, increase the length of intestinal villi, thereby increase the surface area of the intestine, promote nutrient absorption, and lead to obesity. The fructose diet promotes tumor growth and provides a convincing explanation.
In addition, in February 2021, a research paper published in the journal Nature Communications entitled: Fruitose reprogrammes glutamine-dependent oxidative metabolism to support LPS-induced inflammation showed that a short-term high fructose diet can induce inflammation of the immune system. It will continue to damage cells and tissues, and cause organs and body systems to fail to function properly, and may further lead to diseases. Moreover, low levels of inflammation are usually related to obesity.
These studies remind us: Before drinking a high-fructose beverage, you have to think twice.
(source:internet, reference only)