In previous articles, I discussed the importance of eating little or no meat (especially beef)1-3. Unfortunately, the food industry is a powerful force working against this idea. Clever marketing continues to increase the demand for mass-produced beef throughout the world. So, it’s especially disappointing when news agencies publish headlines like this one: “Vegan and Plant-Based Diets Worsen Brain Health”4. The anonymous author of this article wrote that it was based on an article that was published in the widely respected British Medical Journal Nutrition, Prevention & Health entitled “Could we be overlooking a potential choline crisis in the United Kingdom?” 5. This article refers to the fact that choline is an essential nutrient and that people who don’t eat eggs, dairy products or meat may might want to consume dietary supplements that contain choline, without specifying which ones are available. This could be especially important for pregnant women and young children5. Moreover, the American Medical Association (AMA) advised in 2017 that prenatal vitamin supplements should contain “evidence-based” amounts of choline6. The US FDA set a daily value of choline at 550 mg for adults and children age 4 years and older7. Perhaps the most popular dietary supplement that contains choline is called lecithin. It is a type of lipid whose scientific name is phosphatidylcholine, abbreviated as PC8. However, over-consumption of red meat and dietary supplements that contain lecithin can cause a toxin called trimethylamine oxide (TMAO) to be produced. People who have chronic kidney disease or are susceptible to cardiovascular diseases may want to limit their consumption of red meat and egg yolks, as well as lecithin. Instead, a different supplement called citicoline, or CDP-choline, could be a healthier and safer choice8. So, the goals of this article are:
1) to describe the importance of choline in human health
2) to list major dietary sources of choline
3) to describe the toxin TMAO
4) to tell why citicoline might be a preferable dietary supplement for some people.
The importance of choline in human health
Choline is required for the healthy development of the Central Nervous System in fetuses, babies and infants8. It is part of two lipids (lecithin and sphingomyelin) that are needed to maintain the structural integrity of cell membranes and to make the myelin sheath that surrounds the cores of nerve fibers. Choline is also part an important molecule in the brain that is called cytidine diphosphocholine, CDP-choline and citicoline. The need for choline increases during pregnancy and lactation. Human breast milk has a relatively high amount of biochemicals that contain choline, but soy-derived infant formula does not. That could be one reason why people fed breast milk during infancy tend to have higher IQs than those who were not. In addition, choline is part of the important neurotransmitter, acetylcholine (Ach). Ach is needed to transmit nerve impulses, help improve muscle control and memory. Elderly people who suffer from an excessive decline in choline are susceptible to Alzheimer’s disease. Dietary supplementation with compounds containing choline (like lecithin and citicoline) may be able to help prevent Alzheimer’s disease, while improving memory and cognition8,9.
Major dietary sources of choline
The US Department of Agriculture (USDA) Food Composition Database lists the choline content of thousands of foods and beverages10. The major dietary sources of choline are beef liver, chicken liver, eggs, wheat germ, bacon, dried soybeans and pork8,10. However, consuming meat – especially beef – is bad for the environment and one’s health. Egg yolks are the most concentrated dietary source of choline, containing an average of 680 mg per 100 g. Whole eggs have 251 mg of choline per 100 g. So, eggs can be an adequate source of dietary choline for vegetarians, but vegans might need to take a dietary supplement to get adequate choline. There are about 500 mg of PC in a 3600 mg capsule of one source of soy lecithin. This can be useful in estimating the amount of choline in soy lecithin. However, PC molecules contain two fatty acyl side chains each. The size and molecular weight of the fatty acyl side chains varies from one type of PC to another. For example, if the fatty acyls are both relatively short (six carbons as in dihexanoyl PC), the molecular weight is 453.5 g/mol. If the fatty acyls are both relatively long (16 carbons as in dipalmitoyl PC), the molecular weight is 734.0 g/mol. One of the major types of PC in soy lecithin has a molecular weight of 758.1 g/mol, with a palmitoyl on carbon number one and a linoleoyl on carbon number two11. The molecular weight of choline is 104.2 g/mol. So, dihexanoyl PC, dipalmitoyl PC and soy lecithin PC contain 23.0, 14.2% and 13.7% choline, respectively. On the other hand, citicoline has a molecular weight of 489.3 g/mol and contains 21.3% choline.
The US Institute of Medicine recommends that the Adequate Intake (AI) of choline is 425 and 550 mg per day for adult women and men, respectively. The AIs for pregnant and lactating women are 450 and 550 mg per day, respectively. For children under three years of age, the AI of choline is in the range of 100-200 mg per day and 200-400 mg per day for older children8,12,13. So, adult men and women would need to eat an average of about two eggs per day to get their AI of choline. To obtain this, adult vegans who don’t eat eggs or meat would need to take three or four capsules of soy lecithin (containing about 411 or 548 mg of choline) or two capsules of citicoline (containing about 426 mg choline) daily.
TMAO – Toxic to the kidneys and heart
Even though soy and egg lecithin supplements are less expensive than citicoline, they are potentially toxic to the kidneys and heart8. This is because PC is converted to a toxin called TMAO when it is metabolized in the body8,14. TMAO has been shown to be not only a risk factor for cardiovascular diseases, but also a biomarker for chronic kidney disease8. Moreover, an amino acid that is found in red meat and sold as a dietary supplement, L-carnitine, can also be metabolized into TMAO8,15, which promotes atherosclerosis (a major risk factor for heart attacks and stroke). So, the articles that upset me so much4,5 completely ignored the dangers of eating meat. They did not include anything about the citicoline either.
Citicoline might be preferable to lecithin for some people
Citicoline is not just a healthy, non-toxic source of choline, but also can improve memory and cognitive function8,15,16. It is metabolized into choline (but not TMAO). Citicoline may also be an excellent addition to the Mediterranean diet that is rich in fruits, vegetables, nuts, grains and olive oil, as well as moderate amounts of whole grain pasta and rice, but little or no red meat. Together, they can help prevent cardiovascular diseases, chronic kidney disease, memory loss and other problems caused by aging.
So, vegans and vegetarians have nothing to fear – despite propaganda that is disguised as science. In contrast, they have plenty to fear from the potential toxicity and environmental damage caused by the mass production of meat – especially beef1-3.
1 Smith, R.E. Don’t Eat Meat. Save Yourself and the Planet. Wall Street International, 24 October 2018.
2 Smith, R.E. Switching to Plant-Based Diet from Animal-Based Food. Continuously Improving Dietary Guidelines. Wall Street International, 24 September 2019.
3 Smith, R.E. Historical Differences in Dietary Guidelines. Continuously Improving Dietary Guidelines. Wall Street International, 24 October 2019.
4 Neuroscience News. Vegan and Plant-Based Diets Worsen Brain Health. 1 September, 2019.
5 Derbyshire, E. Could We Be Overlooking a Potential Choline Crisis in the United Kingdom? BMC Nutrition, Prevention & Health, published online, 2019. Doi:10.1136/bmjnph-2019-000037.
6 Berg, S. AMA Backs Global Health Experts in Calling Infertility a Disease. American Medical Association, 2017.
7 U.S. Food and Drug Administration. Food Labeling: Revision of the Nutrition and Supplement Facts Labels, 2016.
8 Smith, R.E. et al. Lecithin (Phosphatidylcholine): Healthy Dietary Supplement or Dangerous Toxin? The Natural Products Journal. Volume 6, pp. 242-249, 2016.
9 Cohen, B.M. et al. Decreased brain choline uptake in older adults. An in vivo proton magnetic resonance study. Journal of the American Medical Association, Volume 274, pp. 902-902, 1999.
10 USDA Food Composition Database. Choline. 2019.
11 U.S. National Library of Medicine. Soybean Lecithin, 2019.
12 Zeisel, S.H. et al. Choline: An Essential Nutrient for Public Health. Nutrition Reviews, Volume 67, pp. 615-623, 2009.
13 Ozarda, I. et al. Free and Phospholipid-Bound Choline Concentrations in Serum during Pregnancy, after Delivery and in Newborns. Archives of Physiology and Biochemistry, Volume 110, pp. 393-399, 2002.
14 Tang. W.H.W. et al. Intestinal Microbial Metabolism of Phosphatidylcholine and cardiovascular risk. New England Journal of Medicine, Volume 368, pp. 1575-1584, 2013.
15 Grieb, P. Citicoline: A Food That May Improve Memory. Medical Science Review, Volume 2, pp. 67-72, 2015.
16 Alvarez, X.A. et al. Citicoline Improves memory Performance in Elderly Subjects. Methods in Findings Experimental Clinical Pharmacology, Volume 19, pp. 201-210, 1997.