Foods that have similar carbohydrate content can differ in the amount they raise blood glucose, which has given rise to a scale called the glycemic index. A popular diet is based on the idea that people should choose carbohydrates on the lower end of the glycemic scale because they do not cause blood sugar levels to spike, and could help prevent cardiovascular risk factors, including diabetes.

 
However, a new study from from Brigham and Women's Hospital and Harvard Medical School disputes this notion. Researchers gave 163 overweight people with pre-or-mild high blood pressure one of four different diets to follow which varied in glycemic effect.

 

The researchers found that the glycemic index of the diets did not have an effect on sensitivity (a diabetes precursor), cholesterol levels, or high blood pressure.

 

“In the context of an overall DASH-type diet, using glycemic index to select specific foods may not improve cardiovascular risk factors or insulin resistance,” the study authors concluded.