Steven H. Zeisel, MD, PhD
Steven H. Zeisel, MD, PhD, Kenan Distinguished University Professor and Director, Nutrition Research Institute at Kannapolis, in the School of Public Health at University of North Carolina at Chapel Hill.
Researchers continue to look to the Mediterranean region, particularly Greece and Italy, for secrets to heart-healthy eating, since heart disease mortality is so much lower there. Their latest exciting discovery relates to a nutrient called choline, abundant in the Mediterranean diet, especially in fish and eggs. The health benefits of choline and one of its most important metabolites, betaine (which can also be obtained from food sources), are just beginning to be understood, but they range from keeping the liver healthy to boosting brainpower and more. With its assorted virtues, choline is worth learning more about.
As part of a large Greek study called ATTICA, researchers used food questionnaires to investigate dietary habits of 1,514 men and 1,528 women with no history of cardiovascular disease (CVD)… they then collected blood samples from the participants which they used to assess inflammatory biomarkers that indicate higher risk for CVD and other disorders. The biomarkers were C-reactive protein (CRP), interleukin-6 (IL-6), homocysteine and tumor necrosis factor-alpha (TNF-a). Findings: People who ate high amounts of choline and betaine compared with those who ate the lesser amounts had lower concentrations of all four measures.
Although scientists have long been aware of choline, it wasn’t until 1998 that it acquired official status as a required nutrient, when the National Academy of Sciences established a Dietary Reference Intake for it, a move that led scientists to undertake more in-depth research. I spoke with Steven H. Zeisel, MD, PhD, who is the director of the Nutrition Research Institute at the University of North Carolina and a leading expert on choline. He told me that research to date shows that choline exists in every cell and that it helps the body control inflammation. It also protects the liver from fat buildup caused by several problems, including excess alcohol and/or insufficient food intake and contributes to the health and flexibility of cell membranes, including in the brain, thereby allowing nutrients to enter and exit.
Choline is a particularly important brain nutrient, especially for fetal development. Current research shows that maternal choline prompts more rapid division in fetal stem cells in parts of the brain associated with memory, resulting in a greater number of these brain cells — and animal studies show that offspring of mothers fed a high choline diet perform better on memory testing for their entire lifetime. Dr. Zeisel says that scientists believe consumption breeds cellular development not only during fetal development but also throughout the lifespan. Though it has not yet been studied, it is possible that choline given later in life could increase the proliferation of these cells.
Both choline and betaine are relatively easy to incorporate into a healthy and balanced diet. Dietary choline is largely found in animal products — eggs, meat and dairy — as well as fish and potatoes. Betaine is mostly in plant foods, notably beets, spinach and whole wheat. You can find a complete listing of choline-containing foods and their associated betaine metabolite content at this site: fnic.nal.usda.gov. Though there are many forms of choline metabolites, it’s the “total choline” column that has the information you need. Lecithin, often added as an emulsifier to foods, contains choline (about 15% by weight).
Dr. Zeisel says that one-half to one gram (500 mg to 1,000 mg) per day of choline is sufficient. For comparison, with food sources, one large egg has 113 mg choline, 100 g of beef contains about 100 mg of choline and one cup of whole milk has 35 mg choline. In our country it now appears the general population is getting less than optimal levels of choline, with average intake of about one-quarter to one-third of a gram per day. Choline is available in supplements, but Dr. Zeisel warns that very high doses have been linked with vomiting, sweating, low blood pressure and unusual body odor. Betaine supplements are also available and have been used to address high homocysteine levels. Betaine is best taken as betaine-hydrochloride, a supplement that also bolsters stomach acid production with meals (though it is not appropriate for all patients). Speak to a trained professional before taking choline or betaine supplements. Stay tuned… we can expect to see much more research concerning this intriguing area of nutrient research.