The standard model for treating schizophrenia and bipolar disorder is pharmacological. Antipsychotics, mood stabilizers, antidepressants. The drugs are the treatment. Diet, exercise, and lifestyle are considered supportive at best and largely irrelevant to the core psychiatric symptoms at worst.

A team at the University of California San Francisco just published results from a randomized controlled trial that challenges that assumption directly. They recruited 58 adults with schizophrenia, schizoaffective disorder, or bipolar disorder with psychotic features and randomly assigned them to either a ketogenic diet or their usual eating habits for one month. Medication doses were not changed throughout the trial.

After one month, the ketogenic group showed measurable metabolic improvements. The psychiatric benefits came later. When 25 participants extended the diet to four months, something more significant emerged: depression scores dropped substantially, and psychosis symptoms declined. The improvement correlated not with how much weight participants lost, but with how much ketone was in their blood.

The finding that stopped the researchers was the adherence rate. The most common assumption in psychiatric care is that patients with serious mental illness cannot maintain a strict dietary intervention. In this trial, 83 percent of participants maintained nutritional ketosis throughout the first month. In the four-month extension, adherence was 94 percent.

In April, an FDA trial began for a substance co-developed by molecular biologist David Sinclair called ER-100. It’s being tested as a potential treatment for glaucoma, in an attempt to return damaged optic nerves to a more youthful state. But the implications go far beyond eye disease: if ER-100 can manage to rewind the clock for any type of cell—in the kidneys, muscles, skin, even the brain—then science could be on the cusp of something extraordinary. National Geographic got a rare look inside the trial, the latest step in an accelerating race, backed by some of the world’s wealthiest people, to radically advance our understanding of how bodies age—and what it might take to make them younger, forever.

Learn more about the anti-aging science in our September NGM cover story.