Your body needs sugar, but not the white stuff sitting on your kitchen counter. Your body needs a sugar called glucose, the type of sugar found in your blood. Glucose is your body's primary and preferred source of energy. While your entire body needs glucose to function properly, your brain needs the most blood sugar.
Blood Glucose
A blood glucose test measures the amount of sugar in your blood at a specific moment. While it is most often used to help diagnose diabetes, blood glucose levels are also tested if you've been experiencing fainting spells, have sudden onset of confusion or have had a seizure. In general, a normal fasting blood glucose test should measure up to 100 milligrams per deciliter (mg/dL). While a high blood sugar may indicate diabetes, medications, illness and stress can also raise blood sugar levels.
Carbohydrates
The glucose in your blood is important because it supplies your body with energy. The glucose comes from the food you eat. Carbohydrate-containing foods -- including bread, starches, fruits, milk and sweets -- are your body's primary source of glucose. Your body digests these foods and metabolizes them into sugar, or glucose. The glucose enters your bloodstream and is transported to the cells to supply energy. The hormone insulin helps transport the glucose from your bloodstream into your cells.
The Brain
While every cell in your body needs glucose to survive, your brain uses the most. Your brain cells need twice as much blood glucose as any of the other cells in your body, according to the Franklin Institute. Your brain's cells, called neurons, cannot store glucose for later use and must have a steady dose of sugar to function normally. About half of the blood sugar sent to your brain is used by the neurons that send bioelectric signals throughout your nervous system.
Daily Needs
Carbohydrates are an important nutrient in your diet. The U.S. Department of Agriculture recommends that 45 to 65 percent of your diet consist of carbohydrates. On a 2,000-calorie-per-day diet, that means 225 to 325 g of carbohydrates. For normal and healthy brain function, the Institute of Medicine recommends adults consume a minimum of 130 g of carbohydrates each day. For health and improved energy levels, most of your carbohydrate choices should come from healthy sources including fruits, vegetables, whole grains and low-fat dairy foods.
References
- MedlinePlus; Glucose Test -- Blood; David Dugdale
- Institute of Medicine: Dietary Reference Intake Table
- Franklin Institute: Nourish -- Carbohydrates Fuel Your Brain
- American Diabetes Association: Carbohydrate Counting
- U.S. Department of Agriculture; Dietary Guidelines for Americans: Balancing Calories to Manage Weight; 2010
