Understanding Carbohydrates
Carbohydrates provide the body with the fuel it needs for physical activity and for proper organ function. The healthiest sources are fruits, vegetables, and whole grains which provide essential vitamins and minerals, fiber, and a host of important phytonutrients. What are Carbohydrates?
Carbs come from a wide array of foods - bread, beans, dairy, potatoes, pasta, corn, etc. And they come in many forms. The most common and abundant are sugars, fibers, and starches. The basic building block of a carbohydrate is the sugar molecule, which is a simple union of carbon, hydrogen, and oxygen. Starches and fibers are basically chains of sugar molecules. Some contains hundreds of sugars.
Carbohydrates were once grouped into two main categories of simple carbohydrates including sugars such as fruit sugar (fructose), corn or grape sugar (dextrose or glucose),table sugar (sucrose), and complex carbohydrates including everything made of three or more linked sugars. It was once thought that simple sugars were bad and complex carbohydrates good. Now we know there's more to it than that. All carbohydrates are basically handled the same way by the digestive system, which attempts to break them down into single sugar molecules that can pass into the bloodstream. Most digestible carbohydrates are converted into glucose (also called blood sugar), because cells are designed to use this as a universal energy source. However,Fiber is an exception. Since it can't be broken down into sugar molecules, fiber passes through the body undigested.
Carbohydrates and the Glycemic Index The glycemic index is a system of measuring how quickly blood sugar rises, and how high it rises, after carbohydrates are ingested.
For example, white bread is converted to blood sugar almost immediately,causing a rapid spike in blood sugar levels. It is therefore classified as having a high glycemic index. Conversely, brown rice, which digests rather slowly, will convert to less sugar, and will not cause a rapid spike. It therefore has a low glycemic index.
A diet consisting largely of high glycemic foods, which cause consistent spikes in blood sugar, has been linked to an increased risk of diabetes and heart disease.
It's important to understand how blood sugar effects our overall health. As blood sugar levels rise, special cells in the pancreas churn out more and more insulin, a hormone that signals cells to absorb blood sugar for energy or storage. As cells sponge up blood sugar, its levels in the bloodstream fall back to a preset minimum. So do insulin levels. Individuals with type 1 diabetes don't make enough insulin, and their cells can't absorb sugar. Those with type 2 diabetes are insulin resistant. Their cells don't respond well to insulin's signal to open for sugar, which causes both blood sugar and insulin levels to stay high long after eating. Eventually, the insulin-making cells wear out and insulin production slows, then stops. Understanding the glycemic response can help us make better food choices.
One of the main things that determine a food's glycemic index is how highly processed it is. When carbohydrates are processed, the outer, fiber-rich bran is removed, along with the mineral-rich inner germ, and what is left is basically a blob of starch. Other things that influence how fast carbohydrates raise blood sugar include: Fiber ~ Fiber cannot be broken down and acts as a shield which slows the release of sugar molecules into the bloodstream. Ripeness ~ Fruits and vegetables that are ripe will have a higher sugar content and tend to have a higher glycemic index. Starch Type ~ Some types of starch convert more readily into sugar molecules than others. For example, the starch from potatoes converts to sugar more rapidly than the starch from most whole grains. Fats & Acids ~ The higher the fat and acid content of a food, the slower its carbohydrates will convert to sugar and be absorbed into the bloodstream. Now we can see why there's more to it than just simple and complex carbs. Complex carbs like potatoes have a much higher glycemic index than simple carbohydrates such as fruits, which raise blood sugar more slowly than potatoes do.
The Glycemic Load
The glycemic index alone, however, may not tell us everything we need to know about a food's impact on blood sugar levels. For example, it does not tell us the relative amount of carbohydrate a food contains. Watermelon, for example, has a high glycemic index, but it has only a small amount of carbohydrate per serving. To get the whole picture we need to take into account both the amount of carbohydrate in the food and the impact of that carbohydrate on blood sugar levels. Researchers have coined a term for this called,the glycemic load. A food's glycemic load is determined by multiplying its glycemic index by the amount of carbohydrate it contains.
Keeping it Simple
This may seem very complicated - but like most other areas of nutrition it comes back to avoiding processed foods.
~ Choose minimally processed whole-grains over highly processed grains, cereals, and sugars.
~ Keep high glycemic foods like potatoes to a minimum.
~ Eat plenty of fiber.
The information on this web site is intended for educational purposes only, and not as any form of medical advice. You should not use the information contained herein for diagnosing or treating a health problem or disease, or prescribing any medication. If you have or suspect you have a medical problem, contact your health care provider. 
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