It wasn’t until 1998 that Choline was recognised as an essential nutrient by the Institute of Medicine. It is a water-soluble B-group vitamin and some of the richest sources are beef liver, eggs and salmon. Choline plays multiple roles in our biological processes including cell membrane integrity, brain function and liver health. It still doesn’t get the attention it needs and we are consuming sub-optimal levels of choline. Given its role in critical functions, it’s important that it is incorporated as part of a whole food diet.
Why is choline so important?
- Brain and nervous system function. Choline is required in the synthesis of acetylcholine, a neurotransmitter which regulates learning, memory, sleep and muscle function.
- Structural integrity of our cell membranes. One of choline’s metabolites is a compound called phosphatidylcholine which makes up 70-95% of phospholipids in lipoproteins and bile. In addition, it constitutes 40-50% of our cell membranes.
- Lipid (Fat) Transport and Metabolism. Fats and cholesterol are transported to the liver by lipoproteins. Once in the liver, they are packaged into Very Low Density Lipoproteins (VLDL) for transport into the bloodstream. Phosphatidylcholine is required for assembly of VLDL and secretion from the liver. But in the absence of phospatidylcholine, fat and cholesterol will accumulate in the liver.
- Fetal and early year development. It is important that pregnant women and breastfeeding mothers eat a choline-rich diet. Breast milk naturally contains choline but the amount is dependent on how much the mother gets from her diet. Studies show that choline is required for the development of the fetal brain and plays a role in memory and cognitive function. It also decreases the risk of neural tube defects. In a recent article, published in October 2018 in Maternal and Child Nutrition the benefit of eggs in children’s nutrition and pregnant women and the positive effect on brain health due to choline was highlighted.
- Maintaining liver function. Most of choline metabolism occurs in the liver. Choline is an important methyl donor (alongside folate, methionine and betaine) and has a role to play in the methylation of DNA. This has an impact on the epigenetic modulation of gene expression. Methylation occurs mainly in the liver and a diet low in choline can result in liver damage and non alcoholic fatty liver. This is because the pathways for the development of these conditions are epigenetically regulated. People with SNPs (Single Nucleotide Polymorphisms) in their genes for choline metabolism are more likely to develop liver dysfunction. Interestingly pre-menopausal women have less incidence of fatty liver because they are somewhat protected by oestrogen which induces the hepatic gene PEMT which to produce phosphatidylcholine. However, in over 20% of premenopausal women with a SNP in the PEMT gene, these women will need to consume a choline-rich diet to prevent incidence of fatty liver.
Rich dietary sources of choline (per 100g)
- Beef liver , 333mg
- Egg yolk, 294 mg
- Chickpeas, 99mg
- Salmon, 95mg
- Chicken breast, 67mg
- Cauliflower, 44mg