Moderate low-carbohydrate diet is beneficial for adults with type 1 diabetes
A moderate low-carbohydrate diet for adults with type 1 diabetes has advantages over traditional diet. The average blood sugar level is reduced and the time with good values during a 24 hour period is increased, without any negative health impact. This has been shown in a study carried out at the University of Gothenburg.
The study published in The Lancet Regional Health - Europe is the largest of its kind to date. Participants were randomly assigned for different periods in a crossover manner to eat a traditional diet with 50% of the energy from carbohydrates or a moderately low-carbohydrate diet with 30% of the energy from carbohydrates.
This is a moderate reduction in carbohydrates, with 24-hour monitoring of all participants via continuous glucose monitoring (CGM). Blood glucose levels were recorded at least every 15 minutes during the 16 weeks of the study and were followed up by a dietitian and diabetes nurse.
The researchers emphasize that for safety reasons, significant changes in carbohydrate intake in type 1 diabetes should always be made in consultation with the healthcare provider. Individuals should not make these dietary changes on their own, especially not for children with type 1 diabetes. The current study concerns only adults.
Benefits of a moderate low-carbohydrate diet
The 50 participants all had type 1 diabetes with elevated mean glucose, long-term blood sugar, and injection therapy with insulin or an insulin pump. Half were women, and half were men. The average age was 48 years.
Both diets tested were healthy in terms of fat and carbohydrate quality. They included vegetables, fibre-rich carbohydrate sources, unsaturated fats, nuts, seeds and legumes and were individualized by a dietitian.
Participants on a moderately low-carbohydrate diet were found to spend more time within the target range, the range within which people with type 1 diabetes should be in terms of glucose levels. The increase in time within the target range was an average of 68 minutes per day compared to the traditional diet, while the time with elevated values was reduced by 85 minutes per day, overall clinically important changes.
The first author of the study is Sofia Sterner Isaksson, a doctoral student at the Sahlgrenska Academy at the University of Gothenburg and a dietitian in the NU Hospital Group.
“The study shows that a moderately low-carbohydrate diet lowers the average blood sugar level and that more patients can keep their blood sugar within the target range, which is considered beneficial in reducing the risk of organ damage for people with type 1 diabetes,” she says.
No adverse effects of the diet
The researchers saw no evidence of adverse effects. Cholesterol and blood pressure levels were similar for both diets, and participants also felt a bit more satisfied with the moderate low-carbohydrate diet. It has been discussed whether a form of acids, ketones, can become too high when carbohydrates are reduced in type 1 diabetes, but these were also kept at reasonable levels.
“A moderate low-carbohydrate diet can be a good treatment option for adults with type 1 diabetes with elevated glucose levels. However, it is important that the diet is healthy with a particular focus on fat and carbohydrate quality and that the amount of carbohydrates is not too low to be considered safe. Therefore, Healthcare providers should offer help and diet monitoring,” says Sofia Sterner Isaksson.
Responsible for the study is Marcus Lind, professor of diabetology at the University of Gothenburg and senior physician at the research units for diabetes at Sahlgrenska University Hospital and the NU Hospital Group.
“All patients should find the diet that suits them, in consultation with their healthcare professionals, but there has been a lack of sufficiently large studies randomizing participants to different experimental treatments of this kind. Therefore, we must present data showing that a moderately low-carbohydrate diet is effective and safe for adults with type 1 diabetes,” he says.