Grapefruit juice could lower blood sugar in high-fat dieters

Many low-carb or diabetic diets often include an increase in fat consumption.

The ketogentic diet, for example, advocates eating about 60-80 percent of daily calories from fat sources.

For high-fat dieters that don't want to gain weight, a new mouse study reveals that drinking grapefruit juice might help to prevent added pounds, while also providing the added benefit of lowered blood sugar.

"The grapefruit juice lowered blood glucose to the same degree as metformin," said Joseph Napoli, professor and chair of nutritional sciences and toxicology at the University of California, Berkeley. "That means a natural fruit drink lowered glucose levels as effectively as a prescription drug."

Health-promoting properties

In the study, mice were fed a diet that was either 60 percent fat or 10 percent fat for 100 days. During this period they were either given diluted grapefruit juice or sugar water that was similar to the grapefruit juice in terms of calories and sugar content.

Mice who drank the grapefruit juice gained less weight than the other group, and they also had a 13- to 17-percent decrease in blood glucose levels and a three-fold decrease in insulin levels.

Mice who ate a low-fat diet and also drank the grapefruit juice did not see the same benefits as the high-fat dieters.

After ruling out factors like food consumed, calories ingested, and activity levels, the authors said they still couldn't explain how grapefruit juice might influence overall metabolic health.

"Basically, we couldn't see a smoking gun that could explain why or how grapefruit juice affects weight gain," said Andreas Stahl, study author and UC Berekely faculty member. "Obesity and insulin resistance are such huge problems in our society. These data provide impetus to carry out more studies."

Source: University of California, Berkeley