Choline: An Essential Nutrient for Metabolism and Liver Health
Choline [(2-Hydroxyethyl)-trimethylammonium] is a primary amino alcohol and is mostly found in biological systems in the form of phospholipids. The most important choline-containing phospholipid is phosphatidylcholine. This is a member of the phosphoglycerides, consisting of the trivalent alcohol glycerol, to which two fatty acid residues and one phosphate residue are attached. The latter is esterified with choline. Phosphatidylcholine is also known as lecithin. Eggs, soybeans, and liver are rich in choline or phosphatidylcholine. Nutritionally, these compounds belong to the group of vitaminoids, substances with vitamin-like effects.
Choline and Homocysteine Metabolism
Choline contributes to normal homocysteine metabolism. Homocysteine is an amino acid whose elevated blood levels are associated with a higher risk of cardiovascular diseases. Choline helps maintain homocysteine levels within the normal range, contributing to overall cardiovascular health.
Choline and Fat Metabolism
Another important benefit of choline is its involvement in fat metabolism. Choline supports the processing and transport of fats in the body. This is particularly important for energy production and maintaining a healthy body weight.
Choline and Liver Function
Choline contributes to the maintenance of normal liver function. In the form of phosphatidylcholine, choline is the quantitatively most important phosphoglyceride of the cell membrane and is present in high concentration in the membranes of liver parenchyma. There it supports the liver in producing lipoproteins necessary for transporting fats in the blood, thus contributing to liver health and function.
To benefit from these health effects, foods should contain at least 82.5 mg of choline per 100 g or 100 ml or per serving.
Good to Know!
Choline or phosphatidylcholine can be synthesized by the human body from the amino acids serine and methionine. However, this endogenous production is not sufficient to meet the human requirement. For this reason, the US Institute of Medicine (IOM) and the European Food Safety Authority (EFSA) have provided recommendations for adequate choline intake (healthy adults: 400–550 mg/day). In metabolism, choline works closely with vitamins B2, B6, B12, and folate.
Sources
REGULATION (EU) No. 432/2012 OF THE COMMISSION of 16 May 2012
Zeisel, S. H., & da Costa, K. A. (2009). Choline: an essential nutrient for public health. Nutrition Reviews, 67(11), 615-623.
Institute of Medicine. (1998). Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. National Academy Press.
Corbin, K. D., & Zeisel, S. H. (2012). Choline metabolism provides novel insights into non-alcoholic fatty liver disease and its progression. Current Opinion in Gastroenterology, 28(2), 159-165.