The scientific community has long recognized that improving one’s diet and losing weight can decrease the risk of developing type 2 diabetes. The questions and the debate over what type of diet to follow continues, however. A new study evaluating the ketogenic diet (KD), a popular diet that promotes the breakdown of fatty acids rather than carbohydrates, finds that this diet triggers alternative pathways that impair glucose tolerance, one of the hallmarks of type 2 diabetes.

The researchers at the ETH Zurich compared the effects of the KD to a high-fat diet (HFD) on laboratory mice and found that although the KD mice initially appeared metabolically healthy, they ultimately exhibited a greater magnitude of reduced glucose tolerance later on. Conversely, mice fed on a KD diet for 3 days had minimal effects on insulin sensitivity and were reported to be in a “healthy, glucose-tolerant state.” However, when both the KD and HFD fed animals were given a glucose challenge after 3 days, both sets of animals showed impaired glucose clearance and insulin tolerance.

Co-corresponding author and Associate Professor of the Institute of Food Nutrition and Health at the ETH Zurich, Christian Wolfrum, PhD, said that although the ketogenic diet is considered to be healthy, this study reveals that it may raise the risk of insulin resistance and type 2 diabetes. The team has identified a future research question to be whether this diet-induced state of glucose intolerance and insulin resistance may be a physiological adaptation or a signaling of the brain in an altered manner. Wolfrum explained that the importance of their work is addressing diabetes as one of the largest public health issues.

According to the researchers, “These early impairments of glucose homeostasis typically present as a failure of elevated glucose or insulin levels to suppress hepatic glucose output, leading to decreased glucose tolerance.” This is the case in the animals fed on the high-fat diet that also develop glucose intolerance and insulin resistance in the liver and brain after a few days. It may take longer for them to develop profound insulin resistance in the major organs.
 « Click here to return to Diabetes Update.