Pinto beans contain carbohydrates, and all carbohydrates increase blood sugar, although to a different degree. One method of determining whether a carbohydrate-containing food has a large or small effect on blood sugars is called the glycemic index, which ranks how fast and how high a particular food can raise your blood glucose. Pinto beans fall into the low glycemic-index category and as a low GI food have only a small effect on blood sugar.
Glycemic Index Effects
Most of the energy used by cells comes from glucose in the foods you eat or from storage in fat cells. All carbohydrates break down into glucose, but some break down much more quickly than others. Foods that break down quickly cause a steeper rise in blood sugar levels. Foods that break down rapidly are said to have a high glycemic index. Pinto beans, with a low glycemic index of 45, digest slowly, so they cause a slow and more controlled rise in blood sugar.
Determining the Glycemic Index
To determine the glycemic index of a food, researchers give subjects a controlled amount of carbohydrate after an overnight fast. Researchers then draw blood samples over the next two hours to assess the rise in blood sugar, which is compared to the rise that occurs when you eat pure glucose. The glycemic scale ranges from one to 100, with a GI value of less than 55 considered low, like pinto beans.
Effects of Increased Blood Sugars
When glucose enters your bloodstream rapidly and in large quantities, your pancreas releases large amounts of insulin. Insulin helps cells absorb glucose. Large rises in insulin can cause insulin resistance. As cells become resistant to the signals of insulin, the pancreas must release more and more insulin to remove the glucose from the bloodstream. Insulin resistance can lead to type 2 diabetes. By choosing foods like pinto beans over food with a higher GI, you keep blood sugar levels rising slowly and in a controlled fashion, which helps control insulin release.
Considerations
Pinto beans are a low GI food that also serves as a good source of both protein and fiber. However, while the GI of a food may help determine a food's effect on your blood sugar, other factors, such as foods eaten at the same time, portion size and the presence of health conditions such as diabetes can also contribute to its effect on your blood sugar. Also, while pinto beans make a healthy food choice, not all low GI foods are healthy for you.
