With more than 4,300 varieties and a global yearly production of 300 million metric tons, the potato is a very versatile and popular vegetable. Indeed, the International Potato Center ranks potatoes third among the top food crops, after rice and wheat. More than a billion people eat them every year, relying on their rich supply of carbohydrates and other nutrients for nourishment. Just as it does with other complex carbohydrates, your body breaks down potatoes into sugar for energy.
Simple vs. Complex Carbohydrates
Carbohydrates have undoubtedly become the most wanted items on many diets' hit lists. Yet they remain indispensable to your body's normal function as a major source of energy for all your cells. You may eat them in their simple forms, known as sugars, or complex forms, such as starches and fiber. Simple carbohydrates have one or two linked sugar units, while their complex counterparts contain three or more linked units. Starches specifically range from 300 to 1,000 joined sugar units, according to the Georgia State University. Foods like potatoes form these starch granules as a storage form of energy, just like your muscles and liver store glycogen for later energy needs.
Your body ultimately metabolizes any type of carbohydrate you eat into glucose, or blood sugar. For potatoes, the process begins in your mouth, where an enzyme known as salivary amylase breaks down starch into smaller chains or sugars. Some glucose results from this chemical reaction, but the main products are the sugar chains of maltose, maltotriose and dextrins. Digestion intensifies in the small intestine as pancreatic amylase continues the starch breakdown process. Simultaneously, various intestinal enzymes break down the different products of amylase digestion to single sugar units. Some of the most important enzymes involved include maltase, sucrase and isomaltase.
Once your body has digested potato starch into its basic units of glucose, absorption can begin. Glucose absorption primarily occurs in the upper region of your small intestine, although it can continue in the lower regions as enzymes digest more of the remaining starch granules. Multiple hairlike projections on the surface of your small intestine form a brush border and facilitate the absorption process. However, moving glucose from your intestinal surface to the bloodstream requires transport proteins.
Carbohydrates ultimately yield 4 calories of energy per gram, regardless of their origin. However, unlike nutrient-poor refined sugars, plant sources of carbohydrates have much more to offer than just carbohydrates. Plain potatoes, for instance, are not only a low-fat source of carbohydrates but also provide an array of vitamins, calcium and fiber.
- Lippincott's Illustrated Reviews: Biochemistry (3rd Edition); Pamela C. Champe, Ph.D. et al
- International Potato Center: Potato Facts and Figures
- Food and Agriculture Organization of the United Nations: Digestion, Absorption and Energy Value of Carbohydrates
- Georgia State University: Carbohydrates
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