It may not be the focus of many people's diets, but the vitamin choline is more important than once thought, according to new research at Duke University, the University of North Carolina at Chapel Hill and Boston University.
By administering different levels of choline to pregnant rats, researchers have found that the prevalence of choline in the mother's diet has a dramatic effect on brain functions in the offspring, especially memory capacity and attention span.
Choline is a vital nutrient that is a critical signaling chemical in cells, a component of biological membranes and a producer of acetylcholine, a neurotransmitter necessary for brain functions.
Largely because of research done at Duke and UNC, the National Academy of Sciences decided in 1998 that choline is an essential vitamin and gave a recommended daily amount: 550 milligrams per day for men and 425 milligrams for women, and more if the woman is pregnant.
Good sources of choline include eggs, milk, soy products, fish and other meat.
Studying the behavioral effects of choline, Psychological and Brain Sciences Chair Christina Williams examined the relationship between extra choline exposure during gestation and the subsequent mental abilities of the adult.
"We find these adult animals have better memory... and the animals can sustain attention over long periods of time," said Williams.
"These offspring also show better maintenance of memory... They don't show age-related decline in memory," she said.
Animals deficient in choline, even as adults, show lower memory capacities and a far greater decline in memory as they age.
Working on the electro-physiological component of choline research, Duke Clinical Professor of Medical Psychology Scott Swartzwelder has found yet another benefit of choline. "We look at how brain circuits change in reaction to choline, and a major part is how the brain protects itself," said Swartzwelder.
A recent study suggests that animals prenatally supplemented with choline suffer less brain damage from a variety of toxins, including alcohol, and are less susceptible to brain seizures.
Swartzwelder studied the effects of MK-801, a chemical that causes brain damage in animals.
He found that an extra abundance of choline in the diet helped ameliorate the damage done to the brain.
"The chance that [the findings] are transferable to humans is extremely likely," said Williams.
"The expectation is that brain organization is very similar in humans as in rats.... [Humans] probably will need choline, and a lot more than in rats," she said.
Based on the new findings, Steven Zeisel, chair of the UNC School of Medicine's Department of Nutrition, is leading research on human subjects to determine exactly how much choline is needed in the diet.
"The next step is to figure out why choline works the way it does on a cellular level," Swartzwelder said.
"Why do the brain cells from choline-supplemented animals support memory better?" he asked.
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