To most of us, dieting is about losing weight, looking better and feeling healthier, but researchers at the University of Southern California have recently uncovered a diet for which fat loss is secondary to its many other beneficial health effects. A fasting-mimicking diet (or periodic fasting) is classed as a diet in which individuals alternate extended time periods of little or no energy intake with intermittent periods of normal food intake, on a regular basis.The effects of a fasting-mimicking diet have for several years been recognised to improve a myriad of conditions, including cancer, multiple sclerosis, cardiovascular disease, Alzheimer’s disease, Parkinson’s disease, and stroke.
Last month, a clinical trial was published in Science Translational Medicine which involved 100 healthy participants, out of which some followed a normal diet, while some stuck to a fasting-mimicking diet (a low-calorie, low-sugar, low-protein and high-fat diet) for five days per month, over the course of three months. Surprisingly, the subjects on the fasting-mimicking diet exhibited an improvement in biological signs of ageing, cancer, cardiovascular disease and diabetes. To add to this substantial list of benefits, recent discoveries by the same research group reveal that a fasting-mimicking diet can reverse the development of Type I and Type II diabetes, restoring insulin-generating function in the cells of the pancreas.
Diabetes, both Type I and Type II, is characterised by a loss of insulin signalling, which impairs the regulation of blood glucose levels and which can result in hyperglycaemia. This study found that maintaining diabetic mice on a fasting-mimicking diet (4 days fed on a low-calorie, low carbohydrate but high-fat diet, followed by 10 days of normal food intake) caused the generation of new insulin-producing cells in the pancreas and restored insulin signalling and blood glucose regulation. Furthermore, human insulin-producing pancreatic cells were grown in the lab using blood serum from subjects on either a fasting-mimicking diet or a normal diet. The cells grown in fasting-mimicking diet serum were found to produce more insulin than those grown in serum from the normal diet, indicating that the composition of fasted blood contributes to the ability of the cells to produce insulin.
In an interview with the BBC, Dr Valter Longo – principal investigator of the group – said that this dietary intervention enabled the diabetic pancreas to “rebuild” its malfunctioning parts. Pushing the mice into an extreme state then bringing them back caused the cells to reprogramme themselves into functioning cells.These findings are remarkable because current diabetes medication treats the symptoms (such as the lack of insulin signalling) but cannot currently address the initial cause of the condition – the defective pancreatic cells. The possibility of reversing the development of diabetes would be life-changing for diabetes patients, who would finally be relieved of the delicate fine-tuning of insulin and blood glucose levels.
This article was written by Bonnie Nicholson and edited by Teodora Aldea.