Seven years after the end of a trial in which young people at severe risk of developing psychotic disorders were given fish oil tablets, most remain mentally healthy, a new study has found.
The study, presented today at the International Early Psychosis Conference in Japan, lends weight to the theory that concentrated fish oil, which contains omega-3 fatty acids, may help prevent the development of psychosis.
But more evidence is needed to confirm the results, say the international team of researchers including Professors Patrick McGorry and Paul Amminger of the Orygen Youth Health Research Centre at the University of Melbourne.
“If it’s true that omega-3 fatty acids prevent the onset of the likes of schizophrenia and psychosis, and the results are consistent with this belief, then it could be valuable replacement for anti-psychotic drugs during early intervention,” says McGorry.
“[However], omega-3 fatty acids appear to only work at the early warning stage, before the more advanced stages of illness develops,” he adds.
“Once it has developed, anti-psychotics are an essential component, along with cognitive behavioural therapy and other recovery orientated therapies.”
Previous research has found that people with schizophrenia, a severe form of psychosis, have low levels of omega-3 fatty acids in their cells.
Omega-3 fatty acids are a group of polyunsaturated fats that are present in a wide variety of foods, including ‘oily’ fish such as mackerel, salmon, tuna and sardines.
In the original trial, the researchers assessed the impact of a 12-week course of fish oil tablets on 81 young people aged between 13 and 25 who were assessed as being at high risk of developing a psychotic disorder.
Half took capsules containing concentrated marine fish oil (1.2 grams/day), while the other half took a placebo. They were periodically assessed for mental health changes over the following 40 weeks.
At the end of 12 months, 2 out of the 41 people who took fish oil developed psychosis while 11 in the placebo group developed a psychotic disorder.
The recent follow up research shows that seven years after the original trial, four of those who took fish oil capsules have developed a psychotic disorder, compared to 16 from the placebo group.
Those who took the fish oil capsules were also much better at dealing with challenges in their lives, while those who took the placebo tended to move into a psychotic stage more rapidly.
Scientists are unsure how omega-3 fatty acids work, but one theory suggests that it might increase a chemical called glutathione in the temporal lobes in the brain. Glutathione is a key antioxidant that exists in plant and animal cells. It helps prevent damage caused by destructive free radical molecules.
The anti-inflammatory properties of omega-3 fatty acids might also be important. They are also known to interact with dopamine and serotonin in the brain, which are both associated with mood.
“It might be a more general neuro-protective effect,” McGorry says. “We are also currently studying omega-3 fatty acids in relation to depression.”
Omega-3 fatty acids have also been shown to have very few side effects apart from nausea and diarrhoea, have good public acceptance, and are low cost, say the researchers.
But, while the new study shows promise, the researchers can’t confirm the results until two replica trials are analysed. They hope to release the results of these trials next April.