A new study recommends cutting carbs.
Although low-carb diets are often recommended for individuals who are being treated for diabetes, there is little proof that cutting down on carbohydrates has any effect on blood sugar levels in those with diabetes or prediabetes who aren’t receiving medication.
Now, a new study from Tulane University suggests that a low-carb diet may help those with unmedicated diabetes, as well as those who are at risk for developing the condition, reduce their blood sugar levels.
The research, which was published in the journal JAMA Network Open, compared two groups: one that was given a low-carb diet and another that continued eating as normal. After six months, the low-carb diet group experienced higher decreases in hemoglobin A1c, a blood sugar level measure, than the control group. In addition to losing weight, the low-carbohydrate diet group also had reduced 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,” said lead author Kirsten Dorans, assistant professor of epidemiology at Tulane University School of Public Health and Tropical Medicine.
Diabetes is a disorder that affects around 37 million people in the United States and results from the body’s inability to properly utilize insulin and control blood sugar levels. The Centers for Disease Control and Prevention estimate that type 2 diabetes accounts for more than 90% of these cases (CDC). Type 2 diabetes can have a negative influence on one’s quality of life by causing symptoms such as impaired vision, numb hands and feet, and fatigue, as well as more major health issues such as heart disease, vision loss, and kidney disease.
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. Approximately 96 million Americans have prediabetes and more than 80% of those with prediabetes are unaware, according to the CDC. Those with prediabetes 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.
The study involved participants whose blood sugar ranged from prediabetic to diabetic levels and who were not on diabetes medication. Those in the low-carb group saw A1c levels drop 0.23% more than the usual diet group, an amount Dorans 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.
Dorans said the study doesn’t prove that a low-carb diet prevents diabetes. But it does open the door to further research about how to mitigate the health risks of those with prediabetes and diabetes not treated by 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,” Dorans said. “Future work could be done to see if this dietary approach may be an alternative approach for Type 2 diabetes prevention.”
Reference: “Effects of a Low-Carbohydrate Dietary Intervention on Hemoglobin A1c” by Kirsten S. Dorans, ScD, Lydia A. Bazzano, MD, Ph.D., Lu Qi, MD, Ph.D., Hua He, Ph.D., Jing Chen, MD, MMSc, MSc, Lawrence J. Appel, MD, MPH, Chung-Shiuan Chen, MS, Ming-Hui Hsieh, MS, Frank B. Hu, MD, Ph.D., Katherine T. Mills, Ph.D., MSPH, Bernadette T. Nguyen, BS, RDN, LDN, Matthew J. O’Brien, MD, Jonathan M. Samet, MD, MS, Gabriel I. Uwaifo, MD and Jiang He, MD, Ph.D., 26 October 2022, JAMA Network Open.
The study was funded by the National Institute of General Medical Sciences and the California Walnut Commission.