The Case for Choline

It's the newest essential ingredient in the dietary cupboard, added in 1998, and its public profile has been so low that the vast majority of Americans do not consume enough of it. But choline is a rising nutritional all-star, and recent research is proving it to be a vitamin so critical for functioning that all food labels must now declare their choline content.

So far, the most compelling role of choline is to regulate brain development. Maternal intake at the start of and during pregnancy is critical for developing layering of the brain cortex in the fetus, reports Steven Zeisel, director of the Nutrition Research Institute of the University of North Carolina. The need continues during the first few years of life, when brain growth is especially rapid. Problems with judgment and anxiety are just two of the consequences when maternal choline deficiency during pregnancy or lactation undermines cortical development. "These are the results of mouse studies," Zeisel says, "but they likely reflect what happens in people."

Clinical studies add to the evidence that adequate choline consumption during pregnancy is necessary for cognitive capability of offspring throughout life. Higher levels of dietary choline intake during the first and second trimesters of pregnancy resulted in better performance on visual memory tasks in children at 7 years of age, a team of Harvard researchers has found. In a recent study of 234 Swedish adolescents, those with the highest plasma choline levels achieved higher grades on school tests than those with lower blood levels of the nutrient. Other studies suggest that adequacy of choline during early development may play a role in preventing memory decline later in life.

But choline's role is not limited to the brain. It builds every cell membrane and is necessary for the integrity of cells and their ability to send and receive signals. It plays an important role in the liver and is responsible for transporting fats from the liver to the rest of the body. Along with the B vitamin folate, choline is needed for defanging homocysteine, a substance that undermines the integrity of blood vessels and is implicated in cardiovascular and Alzheimer's diseases.

As the precursor molecule to the neurotransmitter acetylcholine, choline also serves both memory and muscle function. Did we mention it seems to be vital for male fertility?

The body produces some choline—but only in women, says Zeisel, because its biosynthesis is tied to estrogen. Even then, almost 50 percent of women have a genetic variation that compromises their ability to turn estrogen into choline. Boys, men, and postmenopausal women must meet all their needs for choline through what they consume. Eggs, chicken, turkey, and salmon are top sources.

The data are worrisome. One recent study, reported in the Journal of the American College of Nutrition, found that most Americans do not consume enough choline. Analysis of data from the 2009-2012 National Health and Nutrition Examination Survey shows that only 6.6 percent of adult Americans achieve an adequate intake of choline. The mean intake is approximately 300 mg a day, versus a recommended level of 550 mg a day.

Choline deficiency is now implicated in conditions as diverse as fatty liver, atherosclerosis, and neurological disorders. Further, Zeisel says, because of possible genetic variations all along the multiple metabolic pathways in which choline is involved, some people may show symptoms of muscle problems and liver dysfunction at levels of choline intake that do not affect other people. Symptoms of inadequacy cover a wide range: low energy level, memory loss, cognitive decline, muscle aches, and mood changes or disorders. Many symptoms are reversible with adequate intake.

The Ages of Choline

Prebirth & Infancy

• Spurs development of neocortex, hippocampus

• Sets neural pathways for lifelong

• memory function

Adulthood

• Maintains visual and verbal memory
• Improves cognitive function
• Provides neuroprotection

Senior years

• Preserves visual and verbal memory
• Protects against cognitive decline

Choline Confidential

• Choline is essential for brain development, particualarly of the cortex, the seat of such high-level functions as judgment.
• Maternal deficiency of choline during pregnancy permanently stunts the developing brain.
• Choline deficiency during pregnancy is now under investigation as a possible cause of autism.
• Low choline intake impairs the structure, motility, and energy of sperm.
• For adults as well as children, choline is essential for neurotransmitter synthesis.
• Liver dysfunction, including fatty liver, is a common consequence of inadequate choline intake.
• Normal muscle function requires choline.
• The U.S. Food and Drug Administration recommends an intake of 550 mg of choline a day.
• Physiologic needs for choline differ significantly by ethnic group.
• Only 7 percent of American women consume the recommended amount of choline.