Scientists have identified naringin, a bioactive compound in grapefruit juice as a key agent in weight loss.
According to the study by researchers at University of California, Berkeley, mice fed a high-fat diet gained 18 percent less weight when they drank clarified, no-pulp grapefruit juice compared with a control group of mice that drank water and juice-drinking mice also showed improved levels of glucose, insulin and a type of fat called triacylglycerol compared with their water-drinking counterparts.
Lead authors of the study, Andreas Stahl and Joseph Napoli, found that Juice-drinking mice also showed improved levels of glucose, insulin and a type of fat called triacylglycerol compared with their water-drinking counterparts and that grapefruit juice lowered blood glucose to the same degree as metformin, a glucose-lowering drug often prescribed for those with Type 2 diabetes, meaning that a natural fruit drink lowered glucose levels as effectively as a prescription drug.
The study also found that the mice that ate the high-fat diet and drank diluted grapefruit juice not only gained less weight than their control counterparts, they also had a 13 to 17 percent decrease in blood glucose levels and a threefold decrease in insulin levels, which reveals greater sensitivity to insulin. (In Type 2 diabetes, the pancreas makes extra insulin to compensate for increased resistance to the hormone.)
The study did not find as big an impact on mice that ate a low-fat diet. Those that drank the grapefruit juice saw a two-fold decrease in insulin levels, but there was no significant change in weight or other metabolic variables.
The study was published in the journal PLOS ONE.