Curbing Type 2: Carb reduction improves blood sugar regulation in diabetics, study says

14 Aug 2019 --- Contrary to conventional dietary recommendations for Type 2 diabetes treatment, patients can better regulate their blood sugar levels if they consume foods with reduced carbohydrate and increased protein and fat content. This is according to a recent study by Bispebjerg Hospital in collaboration with Aarhus University and the Department of Nutrition, Exercise and Sports at the University of Copenhagen, Denmark. The findings may lead to improved nutritional therapy methods for diabetics, the researchers note.

According to the Danish Health Authority, up to 85 percent of newly diagnosed patients with Type 2 diabetes are overweight, and they are typically advised to follow a diet focused on weight loss. This includes an overall calorie deficit, low-fat content and a high content of carbohydrates with a low “glycaemic index” (which indicates how quickly a food affects blood sugar levels). Nutritional therapy is also reportedly important in treating Type 2 diabetes, but the recommendations are unclear.

A significant aspect in Type 2 diabetes treatment is the patient’s ability to regulate blood sugar levels. This new research indicates that a diet with a reduced carbohydrate content and an increased share of protein and fat improves the patient’s ability to regulate his or her blood sugar levels compared with the conventional dietary recommendations. In addition, it reduces liver fat content and also has a beneficial effect on fat metabolism in Type 2 diabetics.

The purpose of the study, published in the journal Diabetologia, was to investigate the effects of the diet without “interference” from weight loss. For that reason, the patients were asked to maintain their weight. “Our study confirms the assumption that a diet with a reduced carbohydrate content can improve patients’ ability to regulate their blood sugar levels – without the patients concurrently losing weight,” explains Senior Consultant, DMSc Thure Krarup, MD, from the Department of Endocrinology at Bispebjerg Hospital.

Patients can better regulate their blood sugar levels if they consume foods with reduced carbohydrate content.He notes that the findings are important because they removed weight loss from the equation. Previous studies have provided contradictory conclusions, and weight loss has complicated interpretations in a number of these studies.

The study was supported by a grant of DKK 4 million (US$600k) from Arla Food for Health. The researchers followed 28 patients with Type 2 diabetes over a total period of 12 weeks. For six weeks, the patients were given a conventional diabetes diet with a high carbohydrate content, and, for the other six weeks, they were given a diet with a reduced carbohydrate content, high protein content and moderately increased fat content. The patients were given the diet types in random order.

“We hypothesized that hemoglobin A1c would decrease as a consequence of the lower postprandial plasma glucose on the carbohydrate-restricted diet. In this respect, our main findings were as expected. Even though we hypothesized that the liver fat content would decrease irrespective of weight loss, the efficacy of the carbohydrate-reduced high-protein diet to reduce liver fat fraction was somewhat of a surprise to us,” Krarup tells NutritionInsight.

Based on the growing body of evidence, dietary recommendations for patients with Type 2 diabetes should be revised, stresses Krarup. “Further intensive research is needed in order to optimise our dietary recommendations for patients with Type 2 diabetes.” However, the findings should be confirmed in large-scale, long-term controlled trials, he adds.

The question remains however whether refined carbs or wholegrain consumption makes a difference. “We aimed to investigate the effects of two specific macronutrient compositions in a highly controlled setting, but the study was not designed to determine if the quality of either of the macronutrients are responsible for beneficial or deleterious metabolic effects,” says Krarup.

“It has been established that carbohydrates, proteins and fat exhibit various effects on the metabolic system. However, based on the present study, we are not yet able to distinguish between the effects of single macronutrients but merely to conclude on the specific matrix under study,” he concludes. 

By Kristiana Lalou