Maternal Obesity Alters Infant Brain Function

High-fat diets during pregnancy can induce lifelong cognitive impairments

Posted Oct 25, 2012

Women who eat an unhealthy high-fat diet prior to and during pregnancy are more likely to give birth to children, particularly males, who are at risk of abnormal behaviors, particularly anxiety, during adulthood.

Physicians frequently warn pregnant women to monitor their caloric intake and maintain a healthy weight prior to and during pregnancy.  Maternal nutritional status, infection, or physical or psychological trauma during pregnancy can all increase the risk of obesity, diabetes and mental disorder in offspring.  In the past, the concern was maternal malnutrition, i.e. that the developing fetus might lack critical nutrients for normal growth.  Today, in the US, the concern has shifted to overnutrition and obesity and the risks faced by the developing fetal brain. 

A recent study published in Behavioural Brain Research (vol 233, p.398, 2012) by scientists at the Institute of Food Nutrition and Health in Switzerland investigated the consequences of a maternal high-fat diet on the psychological wellbeing and emotional health of offspring.

They reported that a high-fat diet prior to mating, during gestation and during lactation produced significant anxiety-related behaviors when the offspring became adults. Overall, maternal obesity may negatively influence brain function for a lifetime, including unwanted effects on brain development, emotional stability and intelligence.

Another study of maternal obesity, published in the International Journal of Developmental Neuroscience (vol 30, p.75, 2012), reported serious inattention problems and a two-fold increase in the incidence of impaired emotional regulation that was still evident five years after birth.  Animal studies have demonstrated that maternal obesity causes developmental abnormalities in areas of the brain responsible for feeding behavior and memory.  These studies determined that the mother’s obesity significantly altered the fetal brain’s neurotransmitters that are responsible for controlling mood and pleasure, leading to increased anxiety and impaired learning and memory.  All of these changes were most noticeable in male offspring.

How does maternal obesity contribute to fetal brain development? A few years ago it became clear that fat cells produce inflammation throughout the body and brain by releasing specialized proteins called cytokines.  The more fat cells you have the more cytokines get released into your blood.  I study the effects of cytokines in the brain.  A few years ago I discovered that these proteins are capable of inducing shrinkage of brain regions that are used in the process of learning.  The longer the inflammation progressed, the more shrinkage occurred and the greater was the memory loss. I recently discussed this concept in TED presentation available here on YouTube.

One recent epidemiological study concluded that by the year 2050 the number of overweight or obese Americans would increase to above fifty percent.  The studies mentioned above predict that as the obesity rate among young women of childbearing age increases the incidence of adult-onset anxiety and related cognitive disorders will likely also increase.

© Gary L. Wenk, Ph.D.  Author of Your Brain on Food (Oxford University Press)

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