A simple way to smooth out a blood sugar spike after eating has been named

Scientists at Kyoto University in Japan have found that olive oil consumed shortly before carbohydrates significantly smooths the post-meal blood sugar spike — at least in mice. The study was published in the journal Diabetes.

In the experiments, mice after an overnight fast were divided into groups: some received olive oil 15 minutes before glucose, others received glucose followed by oil, and a third group (control) received water before glucose. In the animals given oil first, blood glucose levels immediately after eating were significantly lower, especially at the 15- and 30-minute marks; by one hour, the effect had worn off.

The mechanism turned out to be not hormonal alone but a "bundle" of hormones and nerves. In the mice that received oil, the stomach emptied more slowly, and blood levels of glucagon, GIP, and GLP-1 rose. When both glucagon and GLP-1 were blocked simultaneously, the benefit disappeared; if only one pathway was switched off, the effect was preserved. And disruption of vagus nerve signaling weakened the oil's effect even when hormone levels remained unchanged.

"The order in which nutrients reach the intestine can trigger a coordinated hormonal and neural response," noted the study's lead author, endocrinologist Daisuke Yabe. The scientists also tested other fats — flaxseed oil, lard, coconut oil, and fish oil; olive oil overall performed best, although on certain individual measures flaxseed oil and lard were comparable.

The appeal of this approach, according to Yabe, lies in its simplicity: "only how the meal is eaten changes." However, the results were obtained in mice and have not yet been tested in humans, so extrapolating them to the human diet is premature. Nevertheless, the idea of "eating fat before carbohydrates" aligns with the already known practice of food sequencing, which in small human studies has smoothed sugar spikes, and the authors consider it worthy of a full-scale clinical trial.