By the wwai Editorial Team
Recently a topic shot to the top of Chinese social media: "Give us back the white sugar in the ingredient list." Many consumers noticed that in drinks and snacks, white sugar had quietly disappeared from the label, replaced by "high-fructose corn syrup" — while the package cheerfully advertised "no sucrose", making the product seem healthier. But high-fructose corn syrup is neither healthier than white sugar, nor does it have anything to do with fruit.
What Exactly Is High-Fructose Corn Syrup?
High-fructose corn syrup (HFCS) is, in fact, a starch sugar. Its raw material is usually corn starch or cassava starch. During production, the starch is first hydrolyzed into glucose, then enzymes convert part of the glucose into fructose, producing a mixed syrup of glucose and fructose. The "fruit" in its name only means it contains fructose — it does not come from fruit at all.
Manufacturers use it to replace white sugar because it is cheap and convenient. Corn starch is inexpensive and the process is mature, and because the syrup is already liquid it needs no dissolving before blending. HFCS also tastes sweeter at low temperatures, which improves the flavor of chilled drinks.
White Sugar vs. HFCS: What Is Actually Different?
White sugar is mostly sucrose, a disaccharide in chemical terms: one molecule of glucose and one molecule of fructose joined by a glycosidic bond. Sucrose cannot be absorbed directly; it must first be split. On the surface of our intestinal wall, an enzyme called sucrase (invertase) acts on the glycosidic bond, hydrolyzing sucrose into two monosaccharides — glucose and fructose — which are then absorbed separately.
High-fructose corn syrup, by contrast, is already a mixture of glucose and fructose, skipping the digestion step. It can be absorbed and used directly, and its fructose is in a free state.
How Your Body Handles Glucose vs. Fructose
Glucose entering the body stimulates insulin secretion, sends a signal, and produces a sense of fullness that tells you to stop. Fructose barely stimulates insulin and barely triggers fullness signals; it is mainly metabolized by the liver.
The fructose metabolic pathway lacks the feedback regulation that the glucose pathway has. When intake exceeds the liver's processing capacity, excess fructose is converted into triglycerides in the liver, and its intermediate metabolites also generate uric acid. Seen from human metabolism, long-term high fructose intake adds to the liver's metabolic burden and raises the risk of fatty liver; for people with already high uric acid or gout, it may even trigger an attack.
Wait — Does That Mean White Sugar Is Safer?
Not really. Sucrose is "glucose + fructose", and HFCS is also "glucose + fructose". The monosaccharides that finally enter your body are very similar. From a metabolic point of view, both deliver a fructose load to your liver — the difference is small. Replacing one sweetener with the other does not dodge the metabolic cost.
