Researchers continue to test whether restricting calorie intake in mice can prevent brain aging. They’re also working on a pill to help keep the human brain young.

Of all the reasons to rethink how much you’re eating, a healthy, functioning brain in your golden years might be the best motivation.

New research published in The Journal of Neuroscience says that calorie restriction activates an enzyme that delays the loss of neurons and protects brain function.

While testing has only been done in mice, for now, researchers are working on an experimental new drug that may prevent the human brain from aging.

The secret is the enzyme Sirtuin 1 (SIRT1), which prior research suggests can protect cells from the harmful effects of aging, including mental decline.

In 2004, Harvard researchers published a widely-cited study in Science that also determined that calorie restriction promotes cell survival because SIRT1 has a protective effect. That study also involved mice on a calorie-restricted diet.

The latest study examined the effects of SIRT1 on nerve cells in an attempt to find a pharmaceutical equivalent of calorie restriction to delay the onset of nerve cell loss in degenerative brain disorders like Alzheimer’s disease.

“There has been great interest in finding compounds that mimic the benefits of caloric restriction that could be used to delay the onset of age-associated problems and/or diseases,” Dr. Luigi Puglielli, an aging expert at the University of Wisconsin, Madison, who was not involved in the study, said in a press release. “If proven safe for humans, this study suggests such a drug could be used as a preventive tool to delay the onset of neurodegeneration associated with several diseases that affect the aging brain.”

In the newest study, Li-Huei Tsai, Johannes Gräff, and others at the Picower Institute for Learning and Memory, Massachusetts Institute of Technology (MIT), and Howard Hughes Medical Institute decreased the calorie intake in lab mice that were genetically engineered to experience neurodegeneration.

After three months on a restricted diet, the mice were given numerous memory and learning tests and fared better than mice with normal diets. The dieting mice also had delayed neurodegeneration, even though they were genetically predisposed to it.

In a second round of testing, researchers gave a separate group of mice a drug that specifically activates the SIRT1 enzyme. After similar testing, researchers found that those mice had lost fewer brain cells than the mice who didn’t get the drug. The drugged mice performed just as well in testing as the untreated mice.

“The question now is whether this type of treatment will work in other animal models, whether it’s safe for use over time, and whether it only temporarily slows down the progression of neurodegeneration or stops it altogether,” Tsai said in a press release.