I've been doing more research on sugar. What is it, really? What foods break down into sugars? How much is too much? What do carbohydrates have to do with blood sugar? Should we cut out all carbs?
I came across a very informative article by Harvard's School of Public Health.
How are carbohydrates and sugar related?
- "Carbohydrates are found in a wide array of foods—bread, beans, milk, popcorn, potatoes, cookies, spaghetti, soft drinks, corn, and cherry pie. They also come in a variety of forms. The most common and abundant forms are sugars, fibers, and starches.
- The basic building block of every carbohydrate is a sugar molecule, a simple union of carbon, hydrogen, and oxygen. Starches and fibers are essentially chains of sugar molecules. Some contain hundreds of sugars. Some chains are straight, others branch wildly.
- Carbohydrates were once grouped into two main categories. Simple carbohydrates included sugars such as fruit sugar (fructose), corn or grape sugar (dextrose or glucose), and table sugar (sucrose). Complex carbohydrates included everything made of three or more linked sugars. Complex carbohydrates were thought to be the healthiest to eat, while simple carbohydrates weren't so great. It turns out that the picture is more complicated than that.
- The digestive system handles all carbohydrates in much the same way—it breaks them down (or tries to break them down) into single sugar molecules, since only these are small enough to cross into the bloodstream. It also converts most digestible carbohydrates into glucose (also known as blood sugar), because cells are designed to use this as a universal energy source.
- Fiber is an exception. It is put together in such a way that it can't be broken down into sugar molecules, and so it passes through the body undigested. Fiber comes in two varieties: soluble fiber dissolves in water, while insoluble fiber does not. Although neither type nourishes the body, they promote health in many ways. Soluble fiber binds to fatty substances in the intestines and carries them out as a waste, thus lowering low-density lipoprotein (LDL, or bad cholesterol). It also helps regulate the body's use of sugars, helping to keep hunger and blood sugar in check. Insoluble fiber helps push food through the intestinal tract, promoting regularity and helping prevent constipation."
What is insulin, and how does it relate to sugar?
"When you eat a food containing carbohydrates, the digestive system breaks down the digestible ones into sugar, which then enters the blood. 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 begin to fall. That's when other cells in the pancreas start making glucagon, a hormone that tells the liver to start releasing stored sugar. This interplay of insulin and glucagon ensure that cells throughout the body, and especially in the brain, have a steady supply of blood sugar."
What is the glycemic index? What is the glycemic load?
- "A new system, called the glycemic index, aims to classify carbohydrates based on how quickly and how high they boost blood sugar compared to pure glucose.
- Foods with a high glycemic index, like white bread, cause rapid spikes in blood sugar. Foods with a low glycemic index, like whole oats, are digested more slowly, causing a lower and gentler change in blood sugar.
- One of the most important factors that determine a food's glycemic index is how much it has been processed. Milling and grinding removes the fiber-rich outer bran and the vitamin- and mineral-rich inner germ, leaving mostly the starchy endosperm.
- That's why researchers developed a related way to classify foods that takes into account both the amount of carbohydrate in the food and the impact of that carbohydrate on blood sugar levels. This measure is called the glycemic load.
- You can't use the glycemic index to rule your dietary choices. For example, a Snickers bar has a glycemic index of 41, marking it as a low glycemic index food. But it is far from a health food. Instead, use it as a general guide. Whenever possible, replace highly processed grains, cereals, and sugars with minimally processed whole grain products."
Lastly, the article ends with an emphasis on
"Good Carbs, not No Carbs."
- "For optimal health, get your grains intact from foods such as whole wheat bread, brown rice, whole grain pasta, and other possibly unfamiliar grains like quinoa, whole oats, and bulgur. Not only will these foods help protect you against a range of chronic diseases, they can also please your palate and your eyes."
-"The Nutrition Source: Carbohydrates: Good Carbs Guide the Way," by Harvard School of Public Health