Study Finds Choline Deficiency Harms Memory Center In Mammals' Brains

Researchers at the University of North Carolina at Chapel Hill report for the first time in this month's issue of Developmental Brain Research that diet during a critical period of pregnancy can change the birth and death of cells in the developing memory centers of babies' brains.

Dietary deficiency of choline, an essential nutrient, significantly changed the structure of those memory centers - the hippocampus and septum -- by reducing cell division, changing cell migration and by increasing the number of cells that die prematurely. Although the research took place on rats, something similar could happen in human babies, researchers say.

"We already knew that pregnant rats offered extra choline during days 12 to 18 of their 21-day pregnancies had babies that performed much better on memory tests for the rest of their lives," said Dr. Steven Zeisel, chair of nutrition at the UNC-CH schools of public health and medicine. "Even very old rats performed better on such tests as running through a maze."

Because they had no explanation for the improved performance, the UNC-CH group examined brains of unborn rat pups to learn whether they could detect physical differences between those whose mothers received extra choline and those whose mothers did not receive enough.

"For the first time we have shown that the very structure of brain is influenced by what the mothers eat during pregnancy and that this specific nutrient choline appears to be critical," Zeisel said.

Other report authors include Dr. Craig D. Albright, research assistant professor of nutrition, graduate students Amy Y. Tsai and Claudia B. Friedrich and technician Mei-Heng Mar.

The findings are of special interest because the National Academy of Sciences' Institute of Medicine last fall for the first time recommended choline as an essential nutrient for humans, Zeisel said.

Comparable research cannot be done in humans for obvious reasons, he said. Other kinds of studies that compare pregnant women's diets and choline intake with how their children perform in school later would be less direct and could take decades to complete.

"Developing babies get choline from their mothers during pregnancy and from breast milk after they are born," Zeisel said. "Other foods rich in choline include eggs, meat, peanuts and dietary supplements. Breast milk contains much more of this nutrient than many infant formulas."

Pregnancy and nursing make female rats - and presumably women - especially susceptible to becoming choline deficient, the scientist said. The months before and immediately after childbirth appear to be special times when women need more in their diets.

Choline is a vitamin-like substance that is sometimes treated like B vitamins and folic acid in dietary recommendations. The body uses it in making the nerve messenger chemical known as acetylcholine and in making cell membrane - the biological "wrapper" that keeps cells from leaking.

A research report in the British Medical Journal late last year indicated that diet in human newborn alters intelligence, Zeisel said. The National Institute on Aging funds the continuing research.

"The idea that mother's diet is critically important around the time of pregnancy is not limited to the need for choline," he said. "The Institute of Medicine and the Centers for Disease Control recently issued recommendations that all women who might conceive take a folate supplement, for if this nutrient is missing during early development the brain and spinal cord don't form correctly. The choline story now expands our recognition of how important mother's diet really is."