The natural sugars you get from eating an orange are the same type as granulated sugar, but you don't have to worry as much about their impact on your health. Oranges actually contain three different forms of natural sugar, but the sugar gives you an energy boost without spiking blood sugar because it's part of a whole food. You'll also get a significant amount of vitamin C and other beneficial nutrients.
Three Types of Natural Sugar
Fructose is commonly known as "fruit sugar," but it's not the only type of natural sugar in fruits. In fact, it's usually found with other sugars, according to Elmhurst College. That holds true for oranges because they contain fructose, glucose and sucrose. Fructose and glucose consist of a single unit of sugar, so they're called monosaccharides. When glucose and fructose bind together, they create the disaccharide sucrose. Each sugar imparts a different level of sweetness. Sucrose, which you know as table sugar, has a sweetness score of 100. Compared to sucrose, fructose has a score of 140, while glucose is not as sweet and only rates 70 to 80.
Amount in One Orange
One medium-sized navel orange contains 17.56 grams of total carbohydrates, which includes 11.9 grams of natural sugar. Sucrose accounts for half of the total sugar. Another 23 percent of the total comes from glucose, while fructose represents 27 percent of the sugar in an orange. One navel orange has 69 calories. Almost 48 of the total calories come from sugar because each gram of sugar provides 4 calories, according to Iowa State University.
Impact on Blood Sugar
The glycemic index rates carbohydrate-containing foods according to how much they raise your blood sugar. Oranges have a glycemic index score of 40. On the glycemic scale, scores under 55 fall into the low category, so oranges have a small effect on blood sugar. This is due to fiber. One navel orange contains 3.1 grams of dietary fiber, or about 8 percent of women's and 12 percent of men's recommended daily intake. More importantly, oranges are a good source of soluble fiber, which slows the digestion of sugar and prevents a large spike in blood sugar.
Sugar With Nutritional Benefits
Oranges illustrate another reason why natural sugar is healthy, while sugar added to foods contributes to weight gain: They're filled with nutrients; added sugar is just empty calories. One navel orange supplies 82.7 milligrams of vitamin C. This value exceeds women's recommended dietary allowance of 75 milligrams and nearly fulfills the 90 milligrams of vitamin C men should get daily. You'll also get folate, vitamin B-6, potassium and calcium. Oranges contain beneficial phytonutrients called flavonoids. One in particular, hesperetin, may help lower cholesterol and provide antioxidant protection.
- Elmhurst College: Carbohydrates -- Classification
- Elmhurst College: Fructose
- Elmhurst College: Sweeteners
- USDA National Nutrient Database: Oranges, Raw, Navels
- Harvard Health Publications: Glycemic Index and Glycemic Load For 100+ Foods
- Harvard Health Publications: Use Glycemic Index to Help Control Blood Sugar
- Drug Bank: Hesperetin
- Harvard University: Fiber Content of Foods in Common Portions
- Iowa State University: Carbohydrate
- Institute of Medicine: Dietary Reference Intakes