It's no secret that eating fish rich in fatty acids during pregnancy boosts baby's brain health, but a new study dives into the why.

fresh salmon with spices
Credit: Shutterstock

We already knew that eating fish during pregnancy ensures a good balance of the omega 6 and omega 3 fatty acids essential for the brain development of an unborn child.

But now a new study from the Tohoku University's School of Medicine took the premise further, focusing on the effects of dietary lipids in order to give us an explanation for why there's a correlation between eating fish while preggers and the health of your baby's brain.

The answer? An imbalance of omega-6 and omega-3 leads to premature aging of the fetal neural stem cells, which in turn can cause abnormality inside the brain, especially among offsprings.

For the study, Professor Noriko Osumi and collegues looked at female mice. They found that pregnant mice who were fed a diet rich in omega-6 but deficient in omega-3 produced offsprings with a relatively smaller brain. And this abnormal brain development can lead to long-term adverse effects—like anxiety—in the mental state of the offsprings.

The researchers said these findings are significant because an imbalanced diet of excess omega-6 and not enough omega-3 resembles the modern diet of people today. This is due to the fact that most people have poor dietary patterns and are likely to have more omega-6 fatty acids intake from consuming more seed oils and less of the omega-3 fatty acids from fish.

"The results reveal why omega-6 and omega-3 balance is important for future brain function, the researchers said in a statement. "And reinforce earlier suggestions that more fish intake by women during pregnancy can advantageously affect the child's health."

Hollee Actman Becker is a freelance writer, blogger, and a mom. Check out her website for more, and follow her on Twitter at @holleewoodworld.