Can fish oil prevent schizophrenia?

Could schizophrenia be nipped in the bud? Yes, according to a seven-year study by Paul Amminger and colleagues at the University of Melbourne. And the wonder drug to halt this terrifying disease? Fish oil. That remarkable conclusion was published in Nature Communications in August.

Psychiatrist Vaughan Carr, chief of Sydney’s Schizophrenia Research Institute, calls the work “extraordinary”. But adds, “I’d like to see someone independently replicate it”.

Schizophrenics may hear voices, fear their thoughts aren’t private and lose their drive and ability to experience joy. “It’s like a person loses their life,” says Amminger.

Around one in 100 people develop the disease, most often between the ages of 15 and 30. Antipsychotic medications can stop the hallucinations, but also have side-effects such as weight gain and drowsiness. But omega-3 fatty acids don’t have these disadvantages. They have been found at high concentrations in fish oil, and have been earmarked as a possible treatment since the 1990s when researchers suggested schizophrenia might be triggered by a deficit of phospholipids in nerve membranes. Fatty acids are precursors for phospholipids. Since then, research has also shown omega-3 is a precursor for molecules that protect neurons. And recently, it was found that schizophrenia patients have about half as much omega-3 in their red blood cell membranes as healthy individuals do.

Since schizophrenia often begins in the teen years with early warning symptoms such as paranoia, Amminger wondered if a course of fish oil could stop the disease from progressing. Between 2004 and 2007, his team put their theory to the test. They administered a 12-week course of 1.2 grams of omega-3 daily to 41 young people aged between 13 and 25 who had a family history of schizophrenia and had begun to experience mild symptoms. At the same time another group of 40, with the same family history and early symptoms, took a placebo.

A year after treatment, only two of the omega-3 supplemented group had developed full-blown psychosis, compared to 11 in the placebo group.

According to the latest study, seven years after the 12-week fish oil treatment, the psychotic symptoms were still significantly reduced in the supplemented group. While 16 individuals (40%) in the placebo group had developed psychosis, only four (9.8%) of the omega-3 takers had succumbed.

Reducing the risk of full-blown schizophrenia by four-fold is impressive. But Carr points out the study was small, and similar studies have not found this magnitude of effect. “It’s either an extraordinarily effective treatment that needs to be looked at seriously, or it’s a false positive finding,” he says.

Amminger says his group and others are already repeating the trials. He agrees it’s too early to brand omega-3 as a miracle cure, but given there are no side-effects, he says patients with early symptoms of psychosis may as well try a month or two of daily omega-3 supplements to see if there are any benefits. Amminger is also investigating whether omega-3 can help sufferers of depression.

Because the molecular mechanisms leading to psychosis are not clear, it’s difficult to know how omega-3 works. Amminger thinks the supplement acts in two ways – it integrates into the membranes at the ends of neurons to keep them firing smoothly, and it reduces inflammation.

The study might also improve the quality control of commercial fish oil supplements: Amminger says the amounts of omega-3 in these capsules has been found to be much lower than the levels claimed.

So while trials continue, Amminger recommends taking the supplement directly from the source. “If you can eat fish three to four times a week, you’re in the right ball park.”