Warning: Is Grapefruit Juice That Potent?

The said article reports on a study in which mice were fed a combination of a high-fat diet and grapefruit juice still put on weight, but at a lower rate than mice fed a sugary drink.

Their blood sugar levels and insulin sensitivity were better regulated than mice that did not drink the juice.

The mice were given either a high-fat diet or a low-fat diet.

Mice fed a high-fat diet and grapefruit juice had an 18% reduced rate of weight gain when compared to mice given sugary water with the same number of calories as the grapefruit juice. They also had 13% lower fasting blood sugar levels. There was no effect on weight gain in mice fed a low-fat diet.

Drinking grapefruit juice only improved insulin sensitivity, regardless of their diet (in people, reduced insulin sensitivity can be a sign of diabetes).

Grapefruit juice lowered blood sugar as effectively as metformin, a drug used to treat people with type 2 diabetes. However, none of the mice actually had the disease, so this research has little immediate relevance to humans with the condition.

For the time being, people with diabetes should not swap their metformin for grapefruit juice on the basis of this study.