High-fat diet during pregnancy can create depressed offspring

Research has shown that an unhealthy diet during pregnancy can lead to a host of physical problems in offspring.

It can also cause mental health problems that persist into youth, a new study shows.

In a nine-year study, scientists at Oregon Health and Science University found that a group of monkeys that were fed a high-fat diet during pregnancy produced offspring with were more anxious than those whose mothers ate a healthy diet during the same period.

What's more, the mood changes did not go away even after the offspring were put on a healthy diet after weaning, researchers found.

"Given the high level of dietary fat consumption and maternal obesity in developed nations, these findings have important implications for the mental health of future generations," the report said.

Other researchers have observed a range of mental health disorders in children of obese mothers. This is the first study to show that anxious behavior persisted over time.

The researchers found that the newborn monkeys of obese mothers had defects in their brain, with abnormalities in the central serotonin system. Serotonin, a neurotransmitter,  is believed to affect mood as well as appetite, digestion, sleep, memory and sexual desire.

In the United States, nearly half of women are overweight or obese before they become pregnant, according to recent studies by the Centers for Disease Control and Prevention. Obesity during pregnancy can lead to stillbirth or congenital anomalies in newborns. It is also associated with health problems later in life for the mother and the child.

"It's not about blaming the mother," said Elinor Sullivan, an OHSU scientist and senior author on the study. "It's about educating pregnant women about the potential risks of a high-fat diet in pregnancy and empowering them and their families to make healthy choices by providing support. We also need to craft public policies that promote healthy lifestyles and diets."

Scientists studied 65 female Japanese macaques at the Oregon National Primate Research Center in Beaverton. They were divided into two groups: One ate a high-fat diet during pregnancy, the other did not. They produced 135 offspring, both males and females.

The young animals were assessed at 11 months. Researchers found that both males and females in the high-fat group had anxiety disorders.

The findings suggest that diet is at least as important as genetics on behavioral disorders such as anxiety or depression, according to an OHSU pediatric psychiatrist who was not involved in the research.

"I think it's quite dramatic," said Joel Nigg, professor of psychiatry, pediatrics, and behavioral neuroscience in the OHSU School of Medicine. "A lot of people are going to be astonished to see that the maternal diet has this big of an effect on the behavior of the offspring. We've always looked at the link between obesity and physical diseases like heart disease, but this is really the clearest demonstration that it's also affecting the brain."

The researchers said the study provides scientific fodder for developing healthy food programs for pregnant mothers of all socioeconomic classes to reduce mental health disorders in future generations.

The study, published in the journal Frontiers in Endocrinology, was funded with several grants, including from the National Institutes of Health.

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