Sugar serves far more purposes than sweetening your coffee. It is the primary fuel your body runs on, a critical tool in cooking chemistry, a surprisingly effective wound treatment, and even a raw material for biodegradable plastics. Here’s a closer look at the major ways sugar is used, from the everyday to the unexpected.
Fuel for Every Cell in Your Body
The most fundamental use of sugar is as energy. Every cell in your body breaks down glucose (the simplest form of sugar) through a process called cellular respiration, converting it into ATP, the molecule your cells use to power virtually everything they do. This happens in three stages: first, glucose is split in half, producing a small amount of energy; then those halves are processed further in your cell’s mitochondria; and finally, an electron transport chain generates the bulk of the energy. A single molecule of glucose yields roughly 36 ATP molecules total.
Your brain is especially hungry for sugar. It consumes about 20 to 25 percent of all the glucose your body uses, despite making up only about 2 percent of your body weight. This is why low blood sugar can cause confusion, dizziness, and difficulty concentrating. Your brain has very limited ability to store glucose or use alternative fuels, so it depends on a steady supply from your bloodstream.
Browning, Texture, and Flavor in Cooking
Sugar does far more in the kitchen than make things taste sweet. It is essential to two of the most important chemical reactions in cooking: caramelization and the Maillard reaction.
Caramelization happens when sugar is heated past a specific threshold. Table sugar and glucose caramelize around 160°C (320°F), while fructose (the sugar found in fruit) caramelizes much lower, at about 110°C (230°F). As sugar molecules break apart at these temperatures, they produce hundreds of new compounds that create the complex, nutty, buttery flavors associated with caramel, toasted marshmallows, and the browned crust on crème brûlée.
The Maillard reaction is different. It occurs when a sugar reacts with an amino acid (a building block of protein) in the presence of heat. This is the reaction responsible for the golden crust on bread, the sear on a steak, and the deep color of roasted coffee beans. Without sugar, these flavors and colors simply don’t develop.
Beyond browning, sugar plays structural roles in baking. It traps moisture, keeping cakes and cookies soft. It interferes with gluten formation, producing tender textures. It feeds yeast during bread fermentation, generating the carbon dioxide that makes dough rise. And in jams and preserves, high sugar concentrations help set the gel and prevent spoilage by binding up available water so bacteria can’t grow.
Treating Dehydration
One of sugar’s most important medical uses is deceptively simple: oral rehydration therapy. When someone is severely dehydrated from diarrhea or vomiting, plain water isn’t enough because the body struggles to absorb it efficiently. Adding a precise amount of sugar and salt to water changes that. The sugar activates a transport mechanism in the intestinal wall that pulls sodium and water into the bloodstream far more effectively than water alone.
The World Health Organization’s oral rehydration solution calls for 2 tablespoons (30 grams) of sugar and half a teaspoon (3 grams) of salt dissolved in just over 4 cups (about 1 liter) of water. This ratio has saved millions of lives, particularly in developing countries where IV fluids aren’t readily available. It remains one of the most cost-effective medical interventions ever developed.
Wound Healing
Applying sugar directly to wounds is an old practice with real science behind it. Sugar paste creates an extremely high-concentration environment that pulls water out of bacterial cells through osmosis, effectively dehydrating and killing them. At a concentration of about 183 grams of sugar per 100 grams of water, growth of common wound-infecting bacteria like Staphylococcus aureus, E. coli, and Pseudomonas is completely inhibited.
Clinically, sugar paste has been applied to a wide range of difficult wounds: diabetic ulcers, burn injuries, pressure sores, and even open chest wounds following cardiac surgery (alongside IV antibiotics). It has also been used on fungating tumors to control odor. Sugar dressings are inexpensive, widely available, and particularly useful in settings where advanced wound care products are hard to come by.
Preservation and Fermentation
Sugar is one of the oldest food preservatives. At high concentrations, it binds water molecules so tightly that bacteria, mold, and yeast can’t access the moisture they need to grow. This is the principle behind jams, jellies, candied fruit, condensed milk, and honey’s remarkable shelf life. A sugar concentration above about 65 percent effectively halts microbial growth.
Conversely, sugar also fuels fermentation when you want microbial activity. Yeast and bacteria convert sugars into alcohol, carbon dioxide, and organic acids. This is the basis of beer, wine, spirits, bread, yogurt, and kombucha. Sugarcane juice is fermented to produce ethanol, which is used as biofuel in countries like Brazil, where it powers a significant portion of the vehicle fleet.
Industrial and Manufacturing Uses
Sugar is increasingly used as a renewable raw material in manufacturing. One of the most prominent examples is polylactic acid (PLA), a biodegradable plastic made by fermenting sugars from sugarcane, corn starch, or food waste into lactic acid, then polymerizing that lactic acid into a plastic resin. PLA is used in packaging, disposable cups, 3D printing filament, and medical implants like dissolvable sutures. It breaks down in industrial composting facilities, unlike petroleum-based plastics.
Sugar also appears in pharmaceuticals as a coating and filler for pills, making them easier to swallow and helping control how quickly medication dissolves. In concrete production, small amounts of sugar act as a retardant, slowing the setting process so workers have more time to pour and shape large structures. And in the cosmetics industry, sugar granules are a common base for physical exfoliants, while sugar-derived compounds serve as humectants that help skin retain moisture.
Rocket Fuel and Smoke Signals
Sugar mixed with an oxidizer like potassium nitrate creates a solid rocket propellant known colloquially as “rocket candy.” It burns predictably and produces substantial thrust, making it a staple of amateur rocketry and educational demonstrations. The same basic mixture has historically been used in smoke bombs, where incomplete combustion of the sugar produces dense, visible smoke. These applications take advantage of sugar’s high energy density: gram for gram, sugar stores a significant amount of chemical energy that can be released rapidly through combustion.