The pancreas can be triggered to regenerate itself through a type of fasting diet, say US researchers.
Restoring the function of the organ – which helps control blood sugar levels – reversed symptoms of diabetes in animal experiments.
The study, published in the journal Cell, says the diet reboots the body.
Experts said the findings were “potentially very exciting” as they could become a new treatment for the disease.
People are advised not to try this without medical advice.
In the experiments, mice were put on a modified form of the “fasting-mimicking diet”.
It is like the human form of the diet when people spend five days on a low calorie, low protein, low carbohydrate but high unsaturated-fat diet.
It resembles a vegan diet with nuts and soups, but with around 800 to 1,100 calories a day.
Then they have 25 days eating what they want – so overall it mimics periods of feast and famine.
Previous research has suggested it can slow the pace of ageing.