Carbohydrate has become a ubiquitous term that many people don’t understand. Often it is used synonymously with bread and pasta. But there are many possible dietary sources of carbohydrates, including fruits and vegetables.
Despite the frequent misunderstandings, carbohydrates are at the center of many nutritional debates—particularly whether we should eat high- or low-carbohydrate diets. The problem is, not all carbohydrates are made the same. Literally.
All carbohydrates consist of some combination of three simple sugars—glucose, fructose, and galactose. Simple carbohydrates are made up of a single sugar molecule or just a few bound together. As a result, they are broken down quickly. Complex carbohydrates consist of strings of dozens to hundreds of sugar molecules that are broken down slowly and can have many health benefits. For example, fiber is a complex carbohydrate we can’t break down and which plays a critical role in digestion.
Breads and pastas—what many people think of when they think of carbohydrates—contain mostly simple carbohydrates. Candy is also a carbohydrate source made entirely of simple sugars. Fruits and vegetables tend to be higher in complex carbohydrates.
Humans crave sugar—almost more than any other food. A growing body of research is showing that simple sugars are highly addictive. This explains why more and more processed foods often contain high levels of glucose and fructose—more commonly in the form of table sugar and high-fructose corn syrup.
What’s frightening about the increasing introduction of simple sugars into the Western diet is that overconsumption is being linked to almost every inflammatory disease. In 2016, two studies were published in JAMA and the American Journal of Clinical Nutrition—respected peer-reviewed journals—showing that the sugar industry saw the growing body of research linking sugar to heart disease in the 1960s and funded new research to point the finger at fat instead. The result was the low-fat craze of the 1980s and 1990s. Ironically, this is also when the obesity epidemic took off.
Despite the industry’s continued push-back, an enormous body of research is linking high consumption of simple sugar to a vast array of diseases including the metabolic syndrome, diabetes, liver disease, cancer, heart disease, and even neurodegeneration.
The high glycemic load of a diet high in simple sugars is one of the reasons why it is so damaging. All foods are ranked from 1 to 100 on a glycemic index. Setting the high mark, at 100, are glucose (simple sugar) and white bread. A diet consisting of high glycemic index foods is said to have a high glycemic load. And a high glycemic load diet has been associated with inflammation and insulin resistance—both of which, over time, can contribute to diabetes, heart disease, neurodegeneration, and cancer.
