The “grapefruit diet” that gained attention decades ago may actually have something to it. A new study conducted by researchers at the University of California, Berkeley, suggests that perhaps a closer look at grapefruit juice may be warranted.

In the new study, mice were fed a high-fat diet while consuming either clarified, no-pulp grapefruit juice, or just plain water, while having their metabolic health monitored throughout the study.

The researchers fed one group of mice naringin, a bioactive compound found in grapefruit juice that has been noted to be an important agent in weight loss. The other group of mice were fed metformin, a drug that lowers blood glucose, and is often prescribed to patients with Type 2 diabetes.

The juice-drinking mice gained 18 percent less weight compared to the water-drinking control group. The mice that drank grapefruit juice also showed improved levels of glucose, insulin and triacylglycerol (a type of fat ), in comparison to their water-drinking counterparts.

Andreas Stahl and Joseph Napoli, the UC Berkeley faculty members who led the study, were surprised at their findings. “We even re-checked the calibration of our glucose sensors, and we got the same results over and over again. We see all sorts of scams about nutrition. But these results, based on controlled experiments, warrant further study of the potential health-promoting properties of grapefruit juice,” said Stahl in a statement.

The findings of the study are published in the peer-reviewed journal PLOS ONE.