Schizophrenia is a difficult and often lifelong brain disorder to battle, affecting more than 2.5 million adults in America every year. But what if you could prevent developing full-blown illness when early signs of it emerge as a teenager? In a new study, published in the journal Nature Communications, researchers demonstrated the preventive effects of fish oil on a group of young people who were at risk of schizophrenia.

In their study, researchers observed the effects of fish oil in 81 participants between the ages of 13 and 25, the ages in which schizophrenia symptoms start to appear. Fish oil is packed with omega-3 fatty acids and known for its positive effects on brain health. Half of the group was assigned to take fish oil pills, while the other half of the group received placebos. Every 12 weeks, researchers checked on the participants to track their symptoms and see if they developed psychosis, which is one of the early symptoms of schizophrenia. This went on for seven years.

Only 10 percent of those who received fish oil went on to develop schizophrenia or a related psychotic disorder, whereas 40 percent of those who received the placebo went on to develop the illness. The study group was small, but the results were so significant that the researchers now plan to move forward with a larger group.

“This is an amazing finding and we were surprised that the effect at the long-term follow-up was exceeding the results at 12 months,” the study’s lead researcher G. Paul Amminger, a researcher from the University of Melbourne, told Forbes. “This indicates that some cases of psychosis were truly prevented in the omega-3 group. ”

Researchers based their study on a previous experiment they conducted in 2010, which examined how the omega-3 fatty acids affected a group of young people over the course of a year. The results were promising; only five percent of those in the group who took omega-3s developed a psychotic disorder, while 27.5 percent who took a placebo developed a psychotic disorder.

Symptoms of schizophrenia often begin to peak during a person’s teenage years or early adulthood. It’s a serious psychiatric condition that causes a person to think, behave, and perceive the world in unusual ways. According to the Royal College of Psychiatrists, health care providers are hesitant to diagnose people with these types of psychotic disorders at a young age because of the gravity of the illness, and the intensity of the medications used to treat them.

How Does Fish Oil Affect Mental Illness?

Fish oil contains a powerful omega-3 fat known as docohexaenoic acid (DHA). Because the brain is made up of 60 percent fat, it requires more DHA than any other tissue in the body. Each of our 100 billion brain cells is encased in a fatty membrane called myelin, which helps send messages to other brain cells while also absorbing nutrients and blocking toxins. By providing the brain with protective DHA, the chance that something will go awry within its circuitry decreases, according to the study.

Your body doesn’t naturally produce omega-3 DHA, which is why consuming it via diet and supplementation is so important. When you don’t eat DHA fats, your brain turns to other sources to build its fat membranes, using lower-class fats that are less flexible than DHAs. The more flexible the brain cells’ membranes are, the faster and more efficient your brain works. The brain is unable to function at full efficiency as a result, leaving you at higher risk for not only schizophrenia but depression, aggression, anxiety, and bipolar disorder, according to registered dietitian Elizabeth Somer.

There are other types of omega-3s but they’re often found in flaxseed or walnuts, and have only been shown to lower risk of heart disease. When it comes to your brain health, not just any omega-3 will do because they’re not created equally. Besides consuming supplements containing at least 1,000 milligrams of fish oil, dietary sources of DHA include salmon, mackerel, herring, and sardines.

Source: Amminger GP, Schafer MR, Schlogelhofer M, Mlier CM, and McGorry PD. Longer-term outcome in the prevention of psychotic disorders by the Vienna omega-3 study. Nature Communications. 2015.