11/05/2020
In a crossover randomized trial, exogenous ketones improved glucose tolerance during an oral glucose tolerance test (OGTT).
An OGTT is used to measure an individual’s response to glucose, which represents how well we can take in glucose from our blood, and is indicative of how well we metabolize sugar or carbohydrates in our diet. This can be used to diagnose disorders of carbohydrate metabolism such as diabetes and insulin resistance. In short, the procedure involves measuring a patient’s fasting blood glucose before consuming a glucose load (75 grams was used in this study), followed by additional blood glucose measurements to see how long it takes for levels to return to normal. In this study, blood glucose was tested every 15 minutes over a three hour period.
Nine adults with impaired glucose tolerance underwent an OGTT with or without the ingestion of exogenous ketones on two separate occasions. When participants consumed the ketone supplement, blood ketones rose to an average maximum of 2.4 mmol/L at 90 minutes. The ketone supplement drink also significantly reduced blood glucose levels compared to control. Interestingly, the researchers found the ketone supplement increased insulin secretion during the first half of the OGTT. While excess insulin secretion is detrimental over time, remember that just like glucose, insulin is a normal and important component of our metabolism and physiology. In fact, individuals with impaired glucose tolerance often have decreased “early phase” insulin secretion. This insulin is an important signal to the liver to stop producing its own glucose. Without an appropriate early phase insulin response, glucose consumed through food (or drink) in addition to the glucose that your liver is producing in the fasted state, can result in postprandial hyperglycemia. The authors suggest that the enhancement in insulin levels and insulin secretion caused by the ketone supplement may be a possible mechanism for why it improved OGTT results. Of course, this was a small trial, but these findings are certainly interesting and add to our increasing understanding of why exogenous ketones may help manage blood glucose levels. To learn more visit: https://onlinelibrary.wiley.com/doi/pdf/10.1111/jdi.13423
