There are healthy eating habits and foods that most people can choose from. A low-carb diet can help people with prediabetes to drop their A1C levels quickly. A trial published in JAMA Network shows.
While this research showed many benefits to low-carb eating for blood sugar control, Dr. Giulio Romao, associate medical director at the Adult Diabetes Section at Harvard’s Joslin Diabetes Centre, questions whether such a strict approach can be applied in daily life. He says, “Clearly, this study has shown that a low-carb, and even a borderline very low-carb, diet is effective in reducing A1C, which is a measure of blood glucose during the past three months.” It may not be sustainable long-term, however.
Prediabetes is a condition that affects approximately 96 million Americans. This condition is characterized by higher-than-normal-range blood sugar levels and puts people at higher risk for developing full-blown diabetes.
What foods were participants asked to avoid or eat?
The randomized clinical trial considered the gold standard for scientific research, enrolled 150 older adults suffering from untreated prediabetes and less severe diabetes. All were overweight, with an average BMI of 35. Nearly three-quarters were women, and 59% were Black. Half of the participants were randomly assigned to low-carb diets and received frequent counseling, while the other half continued their regular diets.
Low-carb participants had to limit their carb intake to 40 grams daily for the first three months. This is equivalent to the carbs in an English muffin or an apple. Their carb limit was lower at 60 grams per day in months four and six.
Researchers recommended that participants eat more protein and healthier fats. This included non-starchy foods like fish, poultry, and eggs. Participants were instructed to avoid dairy, fruits, legumes, beans, and grains. Throughout the study, low-carb participants received a variety of foods, including olive oil and green beans, tomatoes, and tuna. They also received non-sugar sweeteners and nuts.
What was the result of the study?
All participants were subject to blood tests three and six months after the trial began. Participants who followed the low-carb diet had higher A1C and fasting glucose levels than those who followed the standard diet. The average weight loss was 13 pounds. Although modest, A1C improvements resulted in a nearly 60% reduction in the risk of developing diabetes within three years.
Dr. Romeo states that participants who were white had a lower A1C than those who were black. This is an important fact to know. The study includes many Black participants to help us understand if the responses to low-carb diets are comparable across races. It did not appear to be in this trial.
Did a low-carb diet play a role in better blood sugar control, or was it the other?
No. Dr. Romeo states that it’s difficult to determine how much weight loss low-carbohydrate participants have contributed towards better blood sugar control. Insulin resistance can be reduced by losing fat. He says that this means your body will respond better to insulin. This is very beneficial.
He says that there are two main effects of low-carb diets. Your appetite will be reduced if your body uses other energy from sources than carbohydrates. Your pancreas must produce more insulin if you consume higher amounts of carbs. Consuming fewer carbs lowers insulin resistance and reduces the burden on your pancreas, independent of weight loss.
Other limitations of the study may also have skewed the findings. These include the intensive low-carb diet counseling received by participants and self-reporting daily diets. Dr. Romeo also noted that the study was small and short-term. These attributes would have helped strengthen its findings. He says, “It doesn’t necessarily address how sustainable low-carb diets are, so a 12-month or 18-month study would have been welcome.” “But it’s a good step in the right direction,” he said.
Can a sensible approach to carbs make any difference?
Prediabetic patients may not be able or willing to reduce their carbohydrate intake to those of the study participants. Dr. Romeo believes that cutting out some carbohydrates can result in weight and blood sugar control.
He says that the relatively high carbohydrate intake of bread, sweets and starchy vegetables can be reduced. This can reduce diabetes risk and may also help with weight loss.
