The Dietary Fiber in Oranges

Oranges are a very good source of dietary fiber.

Oranges are a very good source of dietary fiber.

Oranges are known for many things, from their sweet zest to their high vitamin-C content, but they are also very good sources of dietary fiber. Dietary fiber provides many health benefits such as reduced risk of high cholesterol and improved regularity of bowel movements. To get the most dietary fiber from your oranges, consider peeling them and eating the delicious fruit, because orange juice alone doesn't have much fiber.

Benefits of Dietary Fiber

Dietary fiber is the carbohydrate-based material in fruit, vegetables, grains, nuts and legumes that your body doesn’t digest or metabolize. The vast majority of it passes right through your gastrointestinal system essentially intact. However, as the fiber is passing through your intestines it does a few things that are beneficial to your health. For example, water-soluble fiber is able to stick to toxins and cholesterol and eliminate them from your body. It also makes you feel full longer. Water-insoluble fiber, also called cellulose, bulks up the stool, cleans the sides of the large intestine and promotes regular bowel movements. However, eating too much fiber without drinking enough water can lead to constipation.

Fiber Requirements

Females younger than 50 years need about 30 grams of fiber per day, whereas women older than 50 need at least 21 grams daily. In general, men need between 30 and 40 percent more fiber than women, depending on their size. Kids need at least 10 grams of dietary fiber a day, and that requirement increases about 1 gram per year until adulthood. A lack of dietary fiber can lead to sluggish digestion, constipation and reduced absorption in the intestines.

Soluble Fiber in Oranges

The total fiber available from a medium-sized peeled orange, weighing about 130 grams, ranges from 3 grams to slightly more than 4 grams. Valencia oranges tend to have the most fiber, whereas Mandarin oranges tend to have the least, although the amount partially depends on growing conditions and ripeness. In general, about 60 percent of the fiber in oranges is water-soluble. Most of an orange’s fiber is in the white fibrous material between the peel and the flesh, so if you want the most from your orange, don’t remove that part!

Insoluble Fiber in Oranges

About 40 percent of an orange’s fiber is water-insoluble, which means many medium-sized oranges contain about 2 grams of cellulose and other insoluble fibers. In comparison, an 8-ounce glass of fresh-squeezed orange juice has only 0.5 grams of total fiber. Therefore, if increasing the amount of dietary fiber is important to you, you should eat most of your fruit and vegetables whole as opposed to juiced. Furthermore, to maximize your insoluble fiber intake, chew on the seeds of the orange well before you swallow them. The seeds are the most fibrous part of oranges.

 

References

  • Advanced Nutrition and Human Metabolism; James L. Groff et al.
  • Contemporary Nutrition: Functional Approach; Gordon M. Wardlaw et al.
  • The Nutribase Complete Book of Food Counts; Art Ulene

About the Author

Sirah Dubois is currently a PhD student in food science after having completed her master's degree in nutrition at the University of Alberta. She has worked in private practice as a dietitian in Edmonton, Canada and her nutrition-related articles have appeared in The Edmonton Journal newspaper.

Photo Credits

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