Though it’s present in a variety of foods and an essential part of a person’s diet, many people may not have heard of the nutrient choline.
Researchers from the University of North Carolina at Chapel Hill’s Nutrition Research Institute, located at the NC Research Campus in Kannapolis, have studied the impact that diets lacking in choline could have on everything from liver and muscle tissue to brain development.
Steven Zeisel, director of the Nutrition Research Institute, has been working since 1990 on what choline means to a human body. An egg, for example, has about 230 mg of choline, and many other foods – meats, milk, fish, chicken – have enough choline necessary for a healthy diet. Zeisel said the average person should consume about 500 mg of choline per day.
The researchers’ work led the US National Academy of Science to set a minimum amount of choline required for a healthy diet, and this year, the Food and Drug Administration approved labelling on packaging to tell consumers how much choline is in a food product.
Choline intake may be most critical among pregnant women, according to Zeisel, because research indicates that fetuses that receive the proper amount of choline should develop normal brain functions. Zeisel’s team studied the issue with mice and rats.
“It turns out women were designed to deliver choline to their babies through the umbilical cord, and later, through their breast milk,” he said. “With rats, we found that if we change the amount of choline given to a pregnant mother – give her less – what we find is that we dramatically affect brain development. In a recent paper, we showed that brain stem cells don’t mature and develop the kinds of nerves in a brain that are needed for higher-level function. Specifically, we studied the brain cortex where higher-level functions, such as judgment, are stored. We found that mice, whose mothers didn’t have choline for five days during pregnancy, didn’t develop normally and that they had differences in behavior for the rest of their lifetime.”
Zeisel noted the affected mice also had much poorer memories than those whose mothers received the proper amount of choline in their diet.
“If you miss the window during pregnancy, or try to give choline after the baby is born, it’s too late,” he said. “We think this is really important because the same kind of changes in development we see in these mice are the same kind of changes we see in models of autism – certain areas of the brain develop differently. This may be important as to understanding why some children have different brain development than others.”
Zeisel said he has just submitted a proposal to the National Institute of Health to study potential links between autism and a lack of choline during pregnancy.
Zeisel said that studies indicate that the intake of choline is quite marginal in the United States – only seven percent of American women are eating the recommended intake of choline. The lowest quartile of American women are eating half the recommended intake. Worldwide, especially in developing nations, the problem is even worse.
It wasn’t just women who are pregnant that need choline, Zeisel said. The research showed that a lack of choline in a diet could lead to liver and muscle damage.
Zeisel said men and post-menopausal women needed to consume choline, as did about half the pre-menopausal women. One study suggests that low choline in men could lead to fertility issues.
“What we discovered is that the ability to make choline in your liver is turned on by the hormone estrogen, and during pregnancy, estrogen rise provides the ability to make choline to its maximum capacity,” he said. “That’s why young women who have estrogen don’t need to eat choline.”
Why are people not getting enough choline? Zeisel believes the problem is that many of the foods that people are cutting out of their diets – meats, eggs, and other high-protein foods – because of cholesterol concerns happen to be the same foods highest in choline.
“We’ve probably created an artificial situation where choline intake is less than the days where every mother would have fed their child eggs a few times a week for breakfast,” he said.
Zeisel suggests using the US Department of Agriculture’s website to to calculate if your diet is meeting the suggested choline level: https://data.nal.usda.gov/dataset/usda-database-choline-content-common-foods-release-2-2008. Vegetarians and vegans may consider foods such as wheat germ that contain higher levels of choline and fit into their diet.
Zeisel said people don’t need to go overboard on their choline intake. Too much choline can cause bacteria in the stomach to create a fish-like body odor, and could also lead to heart disease. But that data, he said, is very preliminary.
“Like everything else in nutrition, eating the right amount is good for you, and too much of anything can lead to problems,” he said.
Written by Phillip Ramati