Eating oily fish during pregnancy could prevent schizophrenia in the child, new study suggests

September 7, 2017 by David Mazzocchi-Jones, The Conversation
Credit: Sea Wave/Shutterstock

Mice that are deprived of an essential fatty acid, called docosahexaenoic acid (DHA), during pregnancy, are more likely to produce pups that display schizophrenia-like symptoms as adults, according to a new study from Japan.

DHA is an essential fatty acid – "essential" because our bodies can't produce it. It must be obtained from food. Oily fish, such as salmon and sardines, are good sources of dietary DHA. It is well understood that DHA plays a role in brain development. It is especially important during the last three months of pregnancy, and in the first two years of adolescence.

Studies have shown that babies fed on DHA-supplemented formula milk display higher visual acuity and problem-solving at 10 to 12 months. In an animal study, rats deprived of DHA – resulting in a 50-80% reduction in DHA levels in the brain – were shown to have impaired learning and memory. Conversely, dietary DHA supplementation has been shown to improve learning and memory in brain damaged lab rats.

In the Japanese study, conducted by researchers at the RIKEN Brain Science Institute in Tokyo, mice were fed on a free from DHA, prior to conception and up to the point the offspring had been weaned. The mouse pups were then given a standard diet, containing DHA, and tested at eight weeks, which roughly translates to human adolescence.

The cognitive function of the mice was assessed using standard mazes; they needed to find and remember the location of a food reward. And depression and motivation were assessed by monitoring the mice's general activity and how quickly they avoided open spaces in special mazes (mice prefer enclosed spaces).

Mice born from mothers fed on a diet that excluded DHA showed significantly lower performance on the range of tests, compared with mothers fed on a . Consequently, these mice displayed schizophrenia-like symptoms including, impaired cognitive function, and reduced motivation; characteristic of the early stage of disorder. This led the study's authors to suggest that getting enough DHA during pregnancy may protect against schizophrenia-like symptoms in the offspring.

The role of epigenetics

The mechanisms underlying how diet can play such an important role in brain function and health are poorly understood. The dogma of genetics being entirely based on what we inherit, rather than the environment we are exposed to, has been questioned by scientists in recent years. The advent in understanding of the concept of epigenetics has revolutionised the field of genetic science and provided a potential mechanism through which the environment exerts an influence on .

Under epigenetic modification, certain mechanisms can change the way a gene functions, or is expressed – without changing DNA itself – resulting in vastly different outcomes. These mechanisms are in turn activated by environmental factors, including diet.

In the Japanese study, the researchers investigated the levels of two genes (Rxr and Ppar), known to be associated with schizophrenia in humans. They found evidence that these genes had been modified by epigenetic factors, resulting in lower activity in the mice that displayed schizophrenia-like symptoms.

It's very difficult to draw a direct comparison between evidence gained from studies in , to humans. However, the study identified similar low levels of the RxR and Ppar gene in hair follicle samples obtained from schizophrenic patients. This suggests that adequate levels of DHA in the maternal diet protects normal gene function, which in turn protects against expression of genes associated with schizophrenia.

Ultimately, given that to genes can also be passed on to future offspring, this study provides further evidence for the critical role dietary levels of DHA play in brain function and health. Also, given that epigenetic modifications to genes can be passed on, adequate maternal nutrition is not just essential to their offspring, but also to future generations.

Explore further: Prenatal lack of omega-3 and omega-6 fatty acids linked to schizophrenic symptoms in mice

Related Stories

Prenatal lack of omega-3 and omega-6 fatty acids linked to schizophrenic symptoms in mice

September 5, 2017
Researchers at the RIKEN Brain Science Institute in Japan have discovered a process through which changes in nutrition during early mouse pregnancy lead to offspring that develop schizophrenic-like symptoms as adults. Published ...

Study uncovers possible roots of schizophrenia

August 16, 2017
An abundance of an amino acid called methionine, which is common in meat, cheese and beans, may provide new clues to the fetal brain development that can manifest in schizophrenia, University of California, Irvine pharmacology ...

Poor adolescent diet may influence brain and behavior in adulthood

June 19, 2017
Adolescent male mice fed a diet lacking omega-3 fatty acids show increased anxiety-like behavior and worse performance on a memory task in adulthood, according to new research published in The Journal of Neuroscience. The ...

Early supplementation may help offset early-life stress on the adult brain

October 26, 2016
Early-life stress has been shown to impair learning and memory in later life, but new research, published online in The FASEB Journal, suggests that improved nutrition may help offset the negative effects of this stress. ...

Study shows that paternal nutrition affects offsprings' mental fitness

April 4, 2017
The father's lifestyle affects the cognitive skills of his offspring—at least in mice. Scientists at the German Center for Neurodegenerative Diseases (DZNE) have now shown that if male rodents are fed a diet rich in folic ...

Recommended for you

Biomarker, clues to possible therapy found in novel childhood neurogenetic disease

February 22, 2018
Researchers studying a rare genetic disorder that causes severe, progressive neurological problems in childhood have discovered insights into biological mechanisms that drive the disease, along with early clues that an amino ...

Neuroscientists discover a brain signal that indicates whether speech has been understood

February 22, 2018
Neuroscientists from Trinity College Dublin and the University of Rochester have identified a specific brain signal associated with the conversion of speech into understanding. The signal is present when the listener has ...

Study in mice suggests personalized stem cell treatment may offer relief for multiple sclerosis

February 22, 2018
Scientists have shown in mice that skin cells re-programmed into brain stem cells, transplanted into the central nervous system, help reduce inflammation and may be able to help repair damage caused by multiple sclerosis ...

Color of judo uniform has no effect on winning

February 22, 2018
New research on competitive judo data finds a winning bias for the athlete who is first called, regardless of the colour of their uniform. This unique study, published in Frontiers in Psychology, puts to rest the debate on ...

A look at the space between mouse brain cells

February 22, 2018
Between the brain's neurons and glial cells is a critical but understudied structure that's been called neuroscience's final frontier: the extracellular space. With a new imaging paradigm, scientists can now see into and ...

Superagers' youthful brains offer clues to keeping sharp

February 22, 2018
It's pretty extraordinary for people in their 80s and 90s to keep the same sharp memory as someone several decades younger, and now scientists are peeking into the brains of these "superagers" to uncover their secret.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.