Eating too many carbohydrates is largely considered to be bad for our health—leading to weight gain, higher cholesterol levels, and more heart disease risk factors. But when people follow a low-carb diet, the types of carbs they eat may not be so important, finds a new study out of Harvard and Johns Hopkins published this week in the journal JAMA. Following the highly regimented diets of 163 participants (each assigned to one of four diets, all of which contained the same calories but had different carbs), researchers were surprised to find that when overall carb levels were low, the glycemic level of the carbs consumed didn't seem to matter, reports LiveScience.
Some argue that low glycemic diets, with lots of whole grains and low-starch veggies, are better for blood sugar levels and insulin sensitivity. But the New York Times reports that the new findings suggest that low glycemic diets actually worsened insulin sensitivity. "The dogma out there is that a high glycemic index is bad," a former president of the American Heart Association not involved in the study tells the Times. "I hope that ultimately the glycemic index will be left on the shelf." Still, the findings only relate to short-term health effects and didn't take into account the effects on the growing population of adults with Type 2 diabetes. (Diets low in carbs overall also appear to lower blood pressure.)