What are complex carbohydrates

There is some misunderstanding about what are complex carbohydrates, what are their effects on the body and the difference between simple and complex carbohydrates.

I, too, used to be confused. Without fully understanding what are simple and what are complex carbohydrates, I used to think that simple carbohydrates are "sugars" that digest easily and enter the blood stream quickly, causing a sudden sharp rise in the blood sugar level - which, in turn, can cause problems for the body.

And I used to think that complex carbohydrates are those starchy foods that take longer to digest and so do not cause sudden increases in blood sugar levels. Instead, they provide the body with a steady supply of sugar for long-term, sustained energy.

This differentiation is generally correct. But not always. There are some simple carbohydrates, like fructose or fruit sugar, that digests slowly and do not create havoc with blood sugar levels.

At the same time, foods like white bread, white rice and potatoes are complex carbohydrates. Yet they digest quickly and send blood sugar levels shooting upwards almost immediately.

A bit of chemistry...

To understand what are complex carbohydrates, we need to know a bit of chemistry. But don't worry, I will explain it as simply as I can.

First, before we look at what are complex carbohydrates, we need to look at what are carbohydrates in general. These are chemical compounds that consist of only carbon (C) and hydrogen (H) atoms, along with hydrogen.oxygen (OH) molecules.

The chemical name for these compounds is "saccharide" while the common name is "sugar". They mean the same thing as saccharide is merely the Greek word for sugar. There many different types of carbohydrates / saccharides / sugars but these are classified into four main categories:

• monosaccharides, which consist of only one saccharide molecule
• disaccharides, which consist of two saccharide molecules
• oligosaccharides, which consist of three to 10 saccharide molecules
• polysaccharides, which consist of more than 10 saccharide molecules.

So what are simple and what are complex carbohydrates? The answer is simple.

The first two types, mono- and di-saccharides are considered "simple". These are sometimes called "simple sugars". These have chemical names ending with "ose", for example:

• glucose or blood sugar is a monosaccharide. This is the form of sugar present in the blood and is used by the body as fuel for energy.
• fructose or fruit sugar is another monosaccharide. This is the one that does not get converted so quickly into glucose that enters the blood, even though it is a simple carbohydrate.
• sucrose, a disaccharide, is the sugar that we use to sweeten food and drinks.
• lactose, a disaccharide, is the sugar present in milk. Many people, especially Asians and Africans, have difficulty digesting lactose and are said to be "lactose intolerant:.

The next two types, oligo- and poly-saccharides, are considered complex carbohydrates. They are sometimes called complex sugars, or also starch.

Casual classifications

Part of the confusion over what are simple and what are complex carbohydrates arise from the way nutritionists and health authorities sometimes use the terms loosely and casually.

For example, in the 1977 Dietary Goals for the United States, complex carbohydrate were defined as "fruit, vegetables and whole grains" even though fruits contain mainly simple carbohydrates.

Adding to the confusion, some nutritionists use the term "complex carbohydrate" to refer to whole foods, where the carbohydrates are present along with fibre, vitamins, minerals and other nutrients. In this usage, whole grains are considered complex carbohydrates while refined grains are considered simple carbohydrates.

Such casual definitions of "what are complex carbohydrates", in turn, led to the misconception that complex carbohydrates are digested slowly while simple carbohydrates are digested quickly.

Blood sugar levels

But this is an important issue. How quickly cabohydrates are digested, and how quickly they raise the blood sugar level, are more important than whether they are simple or complex.

Because when the blood sugar level rises too quickly and too greatly, serious problems can occur. A slight increase in the blood sugar level will make a person feel more energetic and happy, or in high spirits. Too huge an increase, however, can lead to coma and even death.

To prevent wild fluctuations in the blood sugar level, the pancreas secretes insulin to bring the sugar level back down. When the pancreas has to do this too often, it gets overworked and eventually stops functioning. That is when a person develops diabetes.

Rather than knowing what are simple and what are complex carbohydrates, it is more important to know how different foods affect the blood sugar level. This is where the glycemic index and the related conceot of glycemic load come in useful.

Click here to understand how the glycemic index relates to what are complex carbohydrates.

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