The ketogenic diet now used for epilepsy in children is a tightly controlled high-fat, low-carbohydrate diet that stimulates the production of substances called ketones, produced when body fat is broken down for energy. Although cells normally burn glucose for energy, if the body is starved of carbohydrates, it will start to use ketones as an alternative source of fuel. The diet is high in fat but extremely low in carbohydrates and protein, and failure to adhere to the correct proportions disrupts the diet's effectiveness.
A ketogenic diet meal might include an omelet made with eggs, heavy cream, butter and cheese. Or a small portion of chicken, a bit of fruit and large helpings of fat. The kinds of foods that provide fat include butter, heavy cream, mayonnaise and canola or olive oil. The diet completely eliminates candy, cookies and desserts. All foods must be carefully prepared and weighed on a scale.
The next step is to test the diet on diabetic men and women with kidney failure.
"We don't yet understand how the diet works," Mobb says. "Once we learn that, we can identify ways to mimic the diet's effect."
If this diet works as well on people as it did on the mice, "it would be a dramatic improvement in our ability to slow or reverse the damage caused by diabetes," says kidney specialist Lynda Frassetto, M.D., of the University of California, San Francisco, who was not involved in the research. But that's a big "if" because "it's often true that what you can do in mice cannot be replicated in humans." This is interesting research but not yet ready for prime time, she says.
The study shows that it's feasible to reverse diabetic kidney failure, notes Mobbs. "Whether this is the best way to do it for people is uncertain," he says, "but it can be done. And that should give us all reason to hope."
Nissa Simon is a freelance writer who lives in New Haven, Conn.