NEW ORLEANS — Diabetes patients often receive advice to follow a low-carb diet, but doctors have never been able to establish whether cutting back on carbohydrates also benefits those with diabetes or prediabetes who aren’t taking medication — until now. Researchers from Tulane University have found that a low-carb diet can indeed help both those with unmedicated diabetes and those at risk for diabetes lower their blood sugar.
The team compared two groups to reach this conclusion. One switched to a low-carb diet, while the other just continued eating their usual diet. After six months, the low-carb diet group displayed greater drops in hemoglobin A1c, a marker for blood sugar levels, in comparison to the standard dieting group. Patients eating a low-carb diet also tended to lose weight and had lower fasting glucose levels.
“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,” says lead study author Kirsten Dorans, assistant professor of epidemiology at Tulane University School of Public Health and Tropical Medicine, in a university release.
Roughly 37 million Americans live with diabetes, a condition that occurs when the body doesn’t use insulin properly and thus can’t regulate blood sugar levels. The vast majority of those cases (over 90%) are Type 2 diabetes, according to the CDC. Type 2 diabetes can significantly impact a person’s quality of life, and can cause symptoms including blurred vision, numb hands and feet, and overall tiredness. It can also lead to more serious complications such as heart disease, vision loss, and kidney disease.
What is prediabetes?
This work is particularly noteworthy for prediabetic individuals with A1c levels that are higher than normal but lower than what doctors consider diabetes. The CDC estimates about 96 million Americans have prediabetes and more than 80 percent of those with prediabetes are unaware of their condition. Prediabetes contributes to an increased risk for Type 2 diabetes, heart attacks, and strokes. However, most prediabetics aren’t taking medications to lower their blood sugar levels, which means a healthy diet is even more important.
This project included patients whose blood sugar ranged from prediabetic to diabetic levels and were not on diabetes medications. The low-carb group saw their A1c levels drop 0.23 percent more than the usual diet group, an observation Prof. Dorans calls “modest but clinically relevant.”
Significantly, fats made up around half of the calories eaten by the low-carb group, but those fats were mostly healthy monounsaturated and polyunsaturated fats found in healthier foods like olive oil and nuts. In summation, Prof. Dorans cautions that this work does not prove a low-carb diet can prevent diabetes. However, this study does open up the possibility to conduct further meaningful research regarding how best to mitigate the health risks of those with prediabetes, and those with diabetes not taking medication.
“We already know that a low-carbohydrate diet is one dietary approach used among people who have Type 2 diabetes, but there is not as much evidence on effects of this diet on blood sugar in people with prediabetes,” Prof. Dorans concludes. “Future work could be done to see if this dietary approach may be an alternative approach for Type 2 diabetes prevention.”
The study is published in JAMA Network Open.
