If the findings can be replicated in humans, the diet would have profound implications for personal health and for the nation's health care, says neuroscientist Charles Mobbs of Mount Sinai School of Medicine in New York. "This is the first study to show that a dietary intervention alone is enough to reverse this serious complication of diabetes," says Mobbs, senior author of a paper published online in PLoS One on April 20.
The mice, bred to develop type 1 or type 2 diabetes, were allowed to develop kidney failure, known as diabetic nephropathy. Then half were fed a standard high-carbohydrate diet while the other half ate a high-fat ketogenic diet, typically used to control epilepsy in children.
After eight weeks, kidney failure was reversed in the mice on the ketogenic diet. Their blood glucose returned to normal and the presence of the protein albumin in urine, a strong predictor of the progression of kidney disease, also was corrected.
Controlling blood glucose and blood pressure slows the progression of diabetic kidney disease, but once the kidneys are damaged there currently is no way to repair them. If they fail, dialysis or a kidney transplant is the only option, experts say, which means that reversing the disease would be far more valuable than simply delaying it.
"I believe that glucose metabolism in the cells drives diabetic complications," says Mobbs. "But controlling blood glucose levels alone doesn't correct the complications. We had to go beyond simply correcting blood glucose." In monitoring the diet, the researchers also identified an array of genes not previously associated with diabetic kidney failure. These genes "had been turned on and the ketogenic diet turned them off," Mobb says.
Mobbs says it appears this diet can reverse the genes' harmful effects in as little as a month, basically resetting the genetic switch.