While low-carb diets are often recommended for individuals being treated for diabetes, there is little evidence to show whether eating fewer carbs can impact the blood sugar of people with diabetes or prediabetes who aren’t treated with medications.

Researchers from Tulane University set out to study this question, and found that a low-carb diet can help both those with unmedicated diabetes and those at risk for diabetes lower their blood sugar.

The team compared two groups: one assigned to a low-carb diet and another that continued with their usual diet. After six months, the low-carb diet group had greater drops in hemoglobin A1c, a marker for blood sugar levels, when compared with the group who ate their usual diet. The low-carbohydrate diet group also lost weight and had lower fasting glucose levels.

Those in the low-carb group saw A1c levels drop 0.23% more than the usual diet group, an amount lead author Kirsten Dorans, assistant professor of epidemiology at Tulane University School of Public Health and Tropical Medicine called “modest but clinically relevant.” Importantly, fats made up around half of the calories eaten by those in the low-carb group, but the fats were mostly healthy monounsaturated and polyunsaturated fats found in foods like olive oil and nuts.

“The key message is that a low-carbohydrate diet, if maintained, might be a useful approach for preventing and treating type 2 diabetes, though more research is needed,” Dorans said.

The study’s findings are especially important for those with prediabetes whose A1c levels are higher than normal but below levels that would be classified as diabetes. Those individuals are at increased risk for type 2 diabetes, heart attacks or strokes and are usually not taking medications to lower blood sugar levels, making a healthy diet more crucial. 

To read the study, “Effects of a Low-Carbohydrate Dietary Intervention on Hemoglobin A1c,” click here