It’s the latest buzzword in anti-aging circles—the “fasting-mimicking” diet—a special low-calorie, high-fat diet designed to deliver many of the health benefits of water-only fasting in a way that’s at least a little easier to swallow.

The latest finding shows that it actually may help regenerate pancreas cells that have stopped working because of type 1 or type 2 diabetes. The promise is that semi-fasts could actually reverse diabetes. But there’s a catch—it’s only been shown to work in mice.

Is it too early to get excited?

Background: The pancreas contains insulin-producing beta cells. In type 1 and late-stage type 2 diabetes, these cells stop working—requiring the use of insulin medications. Stem-cell therapies are being studied for their ability to help regenerate these cells, but there are major challenges that need to be overcome. However, fasting has also been shown in some animal studies to stimulate stem cells. Researchers designed a study to find out if a diet that mimics fasting can stimulate the body’s own stem cells enough to rejuvenate beta cells—so that they started producing insulin again, essentially reversing diabetes.

Study: Researchers at University of Southern California (USC) developed a low-calorie diet that contains plenty of fat but very little protein or carbohydrates. It mimics the effects of a water-only fast, causing the body to switch from carbohydrates to fat as fuel. Mice—some with type 1 and some with type 2 diabetes—were given the “fasting-mimicking” diet for four days each week for three months. The researchers examined whether cycles of the fasting-mimicking diet were able to promote the generation of insulin-producing beta cells.

Although the lead study author does not receive financial benefit, the university does have a financial interest in a company (L-Nutra) that sells fasting-mimicking diet kits. These are available to the public for about $300 for a five-day supply, but to buy one you need to either take an online health assessment survey and work with the company’s online dietitian or nurse practitioner…or buy a kit through your own health-care practitioner once he/she has been approved by the company to oversee using its product.

Results: A surprising reversal of diabetes, even in mice in the later stages of the disease. All the type 2 mice regained healthy insulin production, had reduced insulin resistance and demonstrated more stable levels of blood glucose. (The type 1 mice showed benefits, too.) Human pancreas type 1 cells were also examined in this study, and they showed a similar improvement in the ability to produce insulin, too.

Bottom line: It’s exciting new research, but it’s way too early to act on it. More research will be needed before this is recommended for anyone with diabetes.

There has been one small human study by the same team that showed health benefits—71 healthy people followed a fasting-mimicking diet for five days once a month for three months, a less strict regimen than the mice endured. The USC researchers hope to see a larger, longer clinical trial to test whether this approach could actually help people with diabetes—one that might even lead to FDA approval for this approach.

Until then, they emphatically warn that it could be dangerous for anyone with diabetes who is taking insulin (or other drugs) to attempt this approach—even under the supervision of a health-care professional. There simply isn’t enough known, not just about the benefits but the risks, to try this yourself.

On the positive side, it does show that fasting, once dismissed as health quackery, can have health benefits—perhaps extraordinary ones. We already know that intermittent fasting can enhance metabolic health—and even going on a low-carb diet just two days a week may help with weight loss. In the future, people with diabetes may be able to go on a diet that mimics fasting for just five days a month to stave off the progression of the disease. We’re just not there yet.