That is perhaps a clumsy lead-in to my story about the danger of carbohydrates, which is much more insidious than the steel shard my child, thankfully, never found.
Not so long ago, carbohydrates were the good guys and fat was the enemy. A famous study done by one scientist in the 1950s set nutritional thinking and political policy for decades, declaring that eating fat makes you fat and causes heart disease. You are what you eat. Eat fat, get fat. It turns out he was wrong, which is a fascinating story that I will leave for another time. Suffice it to say that the research was flawed, yet we bought it for half a century.
Lowfat food products sprung up everywhere. The nation eschewed fat and chewed carbs and protein. You know the rest of the story. We only got fatter. We are fatter than ever. Along with obesity, we have record rates of diabetes, heart disease and other related problems. After a few decades of this, scientists began to wonder.
The old research was re-examined and discredited. New research was performed, checked and double checked, and out of the swirling millennial fog a new villain emerged: The carbohydrate.
What is so bad about carbs? All carbohydrates are eventually broken down into glucose, a basic energy source. Our pancreas produces insulin to pull the glucose out of our blood into the tissues where it is needed. But too much blood glucose leads to too much insulin, which leads to insulin resistance and diabetes. Insulin also causes increased fat storage in our bodies. It all starts with carbs.
OK, you say, that’s easy enough. Swap one villain for another, and just eat less carbs. The food industry was quick to jump on that bandwagon, churning out tons of low carb products to restock the lowfat shelves.
But it turns out it isn’t quite that simple. All carbs are not created equal, and some are worse for you than others. How dangerous a carbohydrate is depends on its effect on your blood sugar.
Blood sugar is the amount of glucose measured in the blood. It varies over time, depending on what you ate and when. If glucose gets too high for too long in your blood, your insulin will follow suit, and I just told you where that leads.
Sugar scientists came up with a way to quantify the effect a food has on blood sugar. It’s called the glycemic index. Here’s what they did. First thing in the morning they took 10 healthy people and fed them foods containing 50 grams of some kind of carbohydrate. They then measured the glucose in the blood of these lucky folks every 15 to 30 minutes for two hours. They made a graph, x versus y. On the x axis is time, on the y axis is glucose. As you might imagine, the resulting curve looks like a hill. After eating, blood sugar rises and then falls.
The scientists then measured the area under the curve. They compared that area to the result of the same experiment done with pure glucose. Pure glucose is the simplest carb of all, easily absorbed and measured in the blood as itself. It rises sooner, goes higher and gives a bigger area under the curve than anything else. The pure glucose number was assigned to be 100 percent. The other food is expressed as a percent of the pure glucose number and that is the glycemic index. Glycemic index will be somewhere between zero and 100. Sometimes the standard used is not glucose but white bread, because they both act the same. Think about that one.
Glycemic index is a tidy way to categorize carbs, but it doesn’t have great practical application. We tend to eat in portions, not in units of 50 carbohydrate grams of carb. So another measurement was developed, called glycemic load.
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The glycemic load of a food is its glycemic index times the amount of food in a typical serving. The higher the glycemic load, the more it will raise your blood sugar. Foods with a low glycemic load rank from one to 10; those with medium load range from 11-19 and those with high glycemic load rank at 20 or above.
For optimum health, you want to minimize foods that have a high glycemic load and maximize foods with a low glycemic load. Eating that way has been shown, with good science this time, to make a difference in your blood glucose levels, weight control and diabetes prevention.
What makes a food have high glycemic load? It has to do partly with the surface area of the component carbohydrates, which affects how quickly they can be digested and broken down into glucose. For example, a whole kernel of wheat has a smaller total surface area than the flour made from grinding up the kernel into a zillion tiny bits. Whole wheat grain has a lower glycemic load than whole wheat flour. Actual whole grains like rice, oats and wheat berries are better for you than products made with whole grain flour.
The closer a food is to its original natural state, the lower its glycemic load. The more processed a food is, the higher the glycemic load. The glycemic load of your meal can be lowered by eating fewer carbohydrates or eating carbohydrates along with other foods like protein, fat and other carbs with lower glycemic load.
The take home message in all of this is to eat fewer carbohydrates, avoid simple sugars like soda and candy and eat a variety of foods close to or in their natural state. I know you are no 6-year-old with a bag of candy anymore, but you are still young enough, no matter your age, to make choices that can improve your life now and in the long run. Your own health is an investment worth making.
Dr. Peggy Spencer is a physician at Student Health and Counseling and UNM Center for Life. She is also co-author of the book “50 Ways to Leave Your 40s.” Email your questions directly to her at pspencer@unm.edu. All questions will be considered, and all questioners will remain anonymous.
