Too little fiber in Mom’s diet during pregnancy may slow a baby’s mental development, Japanese research suggests.

Animal studies have found that a low-fiber diet during pregnancy slows brain nerve function in offspring. The new study, published July 27 in the journal Frontiers in Nutrition, shows the same effect in humans.

“Most pregnant women in Japan consume far less dietary fiber than what is the recommended intake,” said study leader Kunio Miyake, an assistant professor of environmental genetics at the University of Yamanashi.

“Our results provided reinforcing evidence that undernutrition during pregnancy is associated with an increased risk of neurodevelopmental delay in children,” Miyake said in a journal news release.

For the study, the researchers compared the development of children whose mothers ate the most fiber to those of mothers who consumed less fiber. The study included 76,000 mother-infant pairs who were part of the Japan Environment and Children’s Study.

Compared with children whose mothers ate the most fiber during pregnancy, those whose moms ate the least were more likely to show neurodevelopmental delays. The delays affected communication, problem-solving and personal-social skills.

Researchers also saw delayed development of movement and coordination.

In Japan, the recommended daily dietary fiber intake is 18 grams; in the United States and Canada, it is 28 grams.

“Our results show that nutritional guidance for pregnant mothers is crucial to reduce the risk of future health problems for their children,” Miyake said.

Good sources of dietary fiber include nuts and seeds, whole grains, fruits and vegetables.

More information

For more on dietary fiber, see the Mayo Clinic.

SOURCE: Frontiers in Nutrition, news release, July 27, 2023