Schizophrenia, characterised by hallucinations, delusions and disordered thinking and behavior, affects millions of people worldwide. While drugs used to treat schizophrenia can cause a variety of undesirable side effects for its patients, researchers at Johns Hopkins Medicine in Maryland, US, have singled out a compound from broccoli sprouts that may supplement traditional antipsychotic medicines for schizophrenia.

For the study, the researchers looked at the differences in brain metabolism between those with schizophrenia and healthy controls – 81 participants were selected from the Johns Hopkins Schizophrenia Center alongside 91 healthy controls from the community. The participants were an average of 22 years old, and more than half were men.

When a powerful magnetic resonance spectroscopy (MRS)measured individual chemical metabolites and their quantities in the brains of people with and without psychosis, there was an average 4% significantly lower levels of the brain chemical glutamate in people with psychosis compared to healthy people, as well as a significant reduction of glutathione.

In another study, the researchers found that halting the formation of glutathione resulted in an effect on rat nerve cells similar to those in the brains of people with schizophrenia. In contrast, the chemical sulforaphane, known to make glutathione and found in cruciferous vegetables like broccoli sprouts, pushed the rat brain cells to behave less like the pattern found in schizophrenic brains.

Glutamate is responsible for sending messages between brain cells, and has been linked to depression and schizophrenia, while glutathione is made of glutamate.

Thomas Sedlak, an assistant professor of psychiatry and behavioral sciences at Johns Hopkins, likens the glutamate/glutathione imbalance to a gas tank analogy – a big, full gas tank allows for a longer drive, but those with schizophrenia only have a small gas tank, which empties quickly.

Currently, Sedlak and colleagues are testing sulforaphane to see if it can safely reduce symptoms of psychosis or hallucinations in people with schizophrenia. They have yet to determine an optimal dose or the duration of its efficacy, but advise against using over-the-counter sulforaphane supplements, most of which aren’t regulated by the US Food and Drug Administration (USFDA).

Sedlak hopes to one day prevent some mental illnesses, “For people predisposed to heart disease, we know that changes in diet and exercise can help stave off the disease, but there isn’t anything like that for severe mental disorders yet.”

“It’s possible that future studies could show sulforaphane to be a safe supplement to give people at risk of developing schizophrenia as a way to prevent, delay or blunt the onset of symptoms,” adds Akira Sawa, a professor at the Johns Hopkins University School of Medicine.