- Researchers recently examined the effects of a low-carbohydrate diet in people with prediabetes and people who have mild, untreated type 2 diabetes (T2D).
- In the randomized clinical trial, participants who reduced their carbs saw a modest drop in blood sugar, an indicator of diabetes.
- The study’s findings are somewhat tempered by a variety of variables beyond the researchers’ control.
The link between carbohydrates and type 2 diabetes (T2D) it’s well established, but new research suggests that cutting carbs could help minimize risk for those who may be susceptible to developing the condition.
The study, a randomized clinical trial (RCT) recently published in JAMA Open Network Diabetes and Endocrinologyfound that a low carb diet promoted weight loss and improved fasting glucose levels in subjects who were at risk of developing T2D.
Lead author and epidemiologist Kirsten S Dorans from Tulane University in New Orleans, LA, said Today’s medical news:
“While low-carbohydrate diets are often recommended for people with type 2 diabetes, there is little evidence that eating fewer carbohydrates can affect blood sugar in people with mild diabetes or prediabetes who are not treated with medication. This study was done in people with blood sugar levels ranging from prediabetes to mild diabetes who were not taking diabetes medications.”
hemoglobin a1c is a widely used clinical term for measuring long-term blood sugar levels.
According to the American Diabetes Foundation, a person who has prediabetes has A1C levels between 5.7 and less than 6.5%. Higher A1C levels can mean diabetes.
Dr. Dorans explained that the subjects enrolled in the study had a hemoglobin A1C range of 6.0 to 6.9%.
“This range chosen as the lower bound aligns with the World Health Organization lower cut-off point for prediabetes and the upper limit with less than 7.0% target hemoglobin A1C of the American Diabetes Association,” he said.
For the study, 150 adults were recruited at an academic center in New Orleans. The 6-month trial took place from September 2018 to June 2021. The participants were between 40 and 70 years old and were divided into two groups.
The first group was tasked with reducing their daily carbohydrate intake to less than 40 grams for the first 3 months and to less than 60 grams from month 3 to the end of the trial.
“We found that nutritional counseling promoting a low-carbohydrate diet lowered hemoglobin A1C over 6 months,” said Dr. Dorans.
“Consistent with previous work, the low-carb diet group also lost a significant amount of weight compared to the group of people following their usual diet.”
At the end of 6 months, Dr. Dorans and her research team found that A1C levels dropped 0.23% more in the low-carb group than in the usual diet group.
Very low-carbohydrate diets, such as ketogenic dietit can trigger a metabolic process known as ketosis, which is when the body burns stored fat for energy instead of glucose.
But ketosis doesn’t usually happen on a low-carb diet.
According to the study authors, “few participants had detectable urinary ketones, suggesting that ketosis is unlikely to explain the findings.”
Yet, Dr. Samuel KleinA professor of cell biology and physiology at Washington University School of Medicine in St. Louis, who was not involved in the study, expressed concern about study participants reaching their carbohydrate goals.
He said MNT the data “shows that there is poor adherence to the diet.”
“It does not mean [study participants] they did not reduce their intake of carbohydrates, but they did not achieve their goals. If they were more obedient, [there] It could have been a bigger change. They must have changed their carbohydrate intake, which reduced their calorie intake. It doesn’t seem like they were very ketogenic.”
– Dr. Samuel Klein, professor of cell biology and physiology
The authors point out a limitation of the study:
“There were significant decreases in caloric intake in the low-carbohydrate diet intervention group during follow-up, which aligns with the large weight loss observed. With this study design, we cannot perform a isocaloric comparison between low-carbohydrate and usual diet groups or to determine effects on HbA1 C [hemoglobin A1C] regardless of weight loss,” the authors wrote.
Dr. Klein noted the amount of contact the low-carbohydrate group had with the study interventionists who offered guidance compared to the usual diet group.
Both groups received a manual containing dietary guidelines and recipes at the beginning of the trial.
To help reach the goal of less than 40 grams of carbs, the carb-reduction group received individual sessions, along with four group sessions every other week and four phone follow-ups. For the 60-gram goal, there were three monthly group meetings and three phone calls.
The usual diet group was offered optional monthly sessions but received no guidance beyond the initial brochures.
“There was much more contact in the treatment group than in the control group,” Dr. Klein said.
Dr Jason Ngclinical associate professor of medicine at the University of Pittsburgh Medical Center, who was not involved in the study, said MNT:
“Improving blood sugar levels through lower carbohydrate intake may be an effective lifestyle treatment for type 2 diabetes. This may or may not influence weight loss, as weight loss has many variables. to consider. However, if you have prediabetes or mild type 2 diabetes, this intervention may lower your blood sugar levels even if you don’t experience concomitant weight loss.”
Dr. Klein added that when you reduce carbohydrate intake and increase fat intake, “you tend to increase LDL cholesterolwhich wasn’t the case here, but it does lower triglycerides and raise HDL cholesterol, which is a good thing.”
But whether a low-carb diet is dangerous to your health can really depend on the individual.
“I would say that we don’t have good evidence of long-term adverse effects. We know a lot of people are on the Atkins diet and we don’t see any real reports of problems,” she said.
.
